WorldWideScience

Sample records for thermophotovoltaics wood powder

  1. Thermophotovoltaics, wood powder and fuel quality

    Energy Technology Data Exchange (ETDEWEB)

    Marks, J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Operational Efficiency; Broman, L.; Jarefors, K. [Solar Energy Research Center, Borlaenge (Sweden)

    1998-06-01

    PV cells can be used for electricity production based on other heat sources than the sun. If the temperature of the source is around 1500 K it is possible to get reasonably high conversion efficiency from heat radiation to electricity. This is due to recent advances in low-bandgap PV cells and selectively emitting fibrous emissive burners. There are some different biomass fuels capable of producing this temperature in the flame, especially gas and liquid fuels of different kinds. Wood powder is the only solid wood fuel with a sufficiently stable quality and properties for this high temperature combustion. A joint project between SERC, SLU and National Renewable Energy Laboratory NREL in Golden, Colorado, USA aims at building a wood powder fuelled thermophotovoltaic (TPV) generator for cogeneration of heat and electricity. A stable flame temperature of 1500 K has been achieved in a prototype pilot-scale burner that includes feeder and combustion chamber. Furthermore, a setup for measuring TPV cell efficiency for a wide region of black body emitter temperatures and cell irradiation has been constructed and several 0.6 eV GaInAs TPV cells have been investigated. A setup for testing the chain IR emitter - selectively reflecting filter - TPV cell has been designed. In order to limit the region of filter incident angles, which will make the filter act more efficiently, a special geometry of the internally reflecting tube that transmits the radiation is considered 23 refs, 4 figs

  2. Effects of Mixing Temperature and Wood Powder Size on Mechanical Properties of Wood Plastic Recycled Composite

    Science.gov (United States)

    Miki, Tsunehisa; Sugimoto, Hiroyuki; Kojiro, Keisuke; Kanayama, Kozo; Yamamoto, Ken

    In this study, wood (cedar) powder ranging from 53 µm to 1 mm sizes, recycled polypropylene (PP) / polyethylene (PE) and acid-modified PP as a compatibilization agent were used to produce a wood-plastic recycled composite (WPRC). For discussing the effects of the wood powder sizes on the mechanical properties of the WPRC, a mixing process of the wood powder and the plastics in a constant wood content of 50% weight was firstly performed by a mixing machine controlled temperature and rotation of mixing blade. And then, to obtain WPRC panels the wood and plastics mixtures were compressed in a mould under a constant pressure and a temperature for a certain holding time. WPRC specimens for mechanical tests were cut from the WPRC panels, and a tensile strength and a size-stability were acquired. The results show that the successful mixing process runs above 180°C, where the mixing torque required compounding keeps constant or slightly increases. The tensile strength of the WPRC increases when the smaller size of wood powder is used for wood/plastic compound under successful mixing conditions. It is shown from thickness change rate of specimens that mixing temperature of wood/plastic compound affects a size stability of the WPRC.

  3. Preparation and characterization of waste wood post- industrial plastic reinforced with wood powder waste

    OpenAIRE

    Wallace Fernando Pedrosa de Paula; Luciana Portal da Silva

    2016-01-01

    The aim of this study is to assess the feasibility of production of composite plastic with wood waste and wood powder with improved properties.Post-industrial waste to be used as base High Density Polyethylene (HDPE) as used plastic wood, called plastic wood waste (RMP) were benefited and mixed with wood dust residues (RPM). The mixtures were prepared with different percentages (by mass) RPM (0, 10, 20, 30 and 40%) in the twin-screw extruder model TeckTrill DCT 40, with L/D: 40 and ten temper...

  4. Preparation and characterization of waste wood post- industrial plastic reinforced with wood powder waste

    Directory of Open Access Journals (Sweden)

    Wallace Fernando Pedrosa de Paula

    2016-04-01

    Full Text Available The aim of this study is to assess the feasibility of production of composite plastic with wood waste and wood powder with improved properties.Post-industrial waste to be used as base High Density Polyethylene (HDPE as used plastic wood, called plastic wood waste (RMP were benefited and mixed with wood dust residues (RPM. The mixtures were prepared with different percentages (by mass RPM (0, 10, 20, 30 and 40% in the twin-screw extruder model TeckTrill DCT 40, with L/D: 40 and ten temperature zones (more the head area, between 135°C and 220°C, with a processing speed of 60 rpm. The profiles obtained in the extruder were analyzed by torque, density, hardness, flow index and Scanning Electron Microscopy (SEM. The results torque, hardness and density showed a proportional increase with the RPM percentage for all compositions suggesting that the RPM load is acting as reinforcement and filling the HDPE matrix. As the melt index composite virgin HDPE/wood flour decreased with increasing RPM content, promoting the systems viscosity increase. This trend was observed for the composite RMP/RPM, probably due to the presence of additives RMP that keeps constant the viscosity of the system. The SEM analysis showed homogeneous materials.

  5. Thermophotovoltaic energy generation

    Science.gov (United States)

    Celanovic, Ivan; Chan, Walker; Bermel, Peter; Yeng, Adrian Y. X.; Marton, Christopher; Ghebrebrhan, Michael; Araghchini, Mohammad; Jensen, Klavs F.; Soljacic, Marin; Joannopoulos, John D.; Johnson, Steven G.; Pilawa-Podgurski, Robert; Fisher, Peter

    2015-08-25

    Inventive systems and methods for the generation of energy using thermophotovoltaic cells are described. Also described are systems and methods for selectively emitting electromagnetic radiation from an emitter for use in thermophotovoltaic energy generation systems. In at least some of the inventive energy generation systems and methods, a voltage applied to the thermophotovoltaic cell (e.g., to enhance the power produced by the cell) can be adjusted to enhance system performance. Certain embodiments of the systems and methods described herein can be used to generate energy relatively efficiently.

  6. Quantum-Well Thermophotovoltaic Cells

    Science.gov (United States)

    Freudlich, Alex; Ignatiev, Alex

    2009-01-01

    Thermophotovoltaic cells containing multiple quantum wells have been invented as improved means of conversion of thermal to electrical energy. The semiconductor bandgaps of the quantum wells can be tailored to be narrower than those of prior thermophotovoltaic cells, thereby enabling the cells to convert energy from longer-wavelength photons that dominate the infrared-rich spectra of typical thermal sources with which these cells would be used. Moreover, in comparison with a conventional single-junction thermophotovoltaic cell, a cell containing multiple narrow-bandgap quantum wells according to the invention can convert energy from a wider range of wavelengths. Hence, the invention increases the achievable thermal-to-electrical energy-conversion efficiency. These thermophotovoltaic cells are expected to be especially useful for extracting electrical energy from combustion, waste-heat, and nuclear sources having temperatures in the approximate range from 1,000 to 1,500 C.

  7. Development of a Wood Powder Fuelled 35 kW Stirling CHP Unit

    DEFF Research Database (Denmark)

    Pålsson, M.; Carlsen, Henrik

    2003-01-01

    due to the slow burning of the fuel. To avoid sintering of ash the flame temperature in a biomass burner has to be quite low. The flame temperature can be lowered by using a high excess air rate; however this will lower system efficiency and needs a large air preheater. By using combustion gas...... recirculation (CGR) a smaller air preheater can be used, while system efficiency will increase compared with using excess air for flame cooling. In a three-year project, a wood powder fuelled Stirling engine CHP unit will be developed and run in field test. The project will use the double-acting four......For biomass fuelled CHP in sizes below 100 kW, Stirling engines are the only feasible alternative today. Using wood powder as fuel, the Stirling engine can be heated directly by the flame like when using a gaseous or liquid fuel burner. However, the combustion chamber will have to be much larger...

  8. Encapsulation and re-use of wood industry waste: varnish powder

    Directory of Open Access Journals (Sweden)

    Acosta, A.

    2006-06-01

    Full Text Available The present article describes the findings of the first stageof the analysis of xiloarcilla, a material made of clayand a wood industry by-product, namely the wood andpolyurethane varnish powder pump-suctioned off woodcomponents during sanding and polishing. This powderwas added to the clay in proportions of from 1% to 5%by weight. The prime materials as well as the xiloarcillacompound were characterized, in the latter case primarilyto determine its physical-mechanical properties andchemical and environmental feasibility as a constructionmaterial.En este articulo se presentan los resultados obtenidos,en una primera etapa, del estudio del material que denominaremoscomo xiloarcilla, compuesto por arcilla y porun subproducto de las industrias de la madera, que eneste caso son los polvos del lijado y del barnizado y excedentesde estos productos utilizados en el acabado demuchos componentes de madera (PLB, estos polvos seadicionaron a la arcilla en cantidades entre el 1% y el5% del peso total del compuesto. Se realizo un estudiode caracterizacion de los materiales aislados y posteriormentedel compuesto xiloarcilla, con enfasis en el comportamientofisico-mecanico y su respuesta quimica ymedioambiental, como material de construccion.

  9. Exploratory experimental and theoretical studies of cyclone gasification of wood powder

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksson, Christian

    1999-11-01

    This thesis describes an exploratory experimental and theoretical study of gasification of wood powder in a cyclone gasifier. The generated gas could be used to operate a gas turbine in a combined cycle power plant. The objective has been to develop the understanding of cyclone gasification by experimental studies of the performance of a cyclone designed in principle as a separation cyclone and by comparisons between the experimental results and theoretical predictions. The experiments were carried out with commercial Swedish wood powder fuels, injected with air or steam/air mixture through two diametrically opposite tangential inlets and gasified at atmospheric pressure in cyclones of two different configurations with a volume of about 0.034 m{sup 3}. The studies show that stable gasification of this fuel can be obtained for a specific fuel feeding rate of about 5 MW/m{sup 3} cyclone volume for equivalence ratios above 0.15 and that the equivalence ratio had to be kept below about 0.4 in order to avoid material temperatures above 950 deg C. A cyclone with a short outlet pipe, designed as a conventional separation cyclone was found to give lower char conversion than a modified cyclone with a long outlet pipe. The heating value of the gas was found to be approximately 4.5 MJ/kg. The dust load in the product gas was measured to between 1000 and 2500 mg/Nm{sup 3}. It was possible to separate at least 40-60% of the potassium and 60-90% of the sodium supplied with the wood. The alkali that left the cyclone with the product gas appear to be in solid or melted phase in the unseparated char particles and consequently not vaporised during gasification. As the K and Na were assumed to remain within the particles during gasification, it was concluded that to reduce the amount of alkali metals in the product gas it would be necessary to improve the particle separation efficiency. The results of the theoretical modelling, using the existing models in the commercial software CFX

  10. A nanophotonic solar thermophotovoltaic device

    Science.gov (United States)

    Lenert, Andrej; Bierman, David M.; Nam, Youngsuk; Chan, Walker R.; Celanović, Ivan; Soljačić, Marin; Wang, Evelyn N.

    2014-02-01

    The most common approaches to generating power from sunlight are either photovoltaic, in which sunlight directly excites electron-hole pairs in a semiconductor, or solar-thermal, in which sunlight drives a mechanical heat engine. Photovoltaic power generation is intermittent and typically only exploits a portion of the solar spectrum efficiently, whereas the intrinsic irreversibilities of small heat engines make the solar-thermal approach best suited for utility-scale power plants. There is, therefore, an increasing need for hybrid technologies for solar power generation. By converting sunlight into thermal emission tuned to energies directly above the photovoltaic bandgap using a hot absorber-emitter, solar thermophotovoltaics promise to leverage the benefits of both approaches: high efficiency, by harnessing the entire solar spectrum; scalability and compactness, because of their solid-state nature; and dispatchablility, owing to the ability to store energy using thermal or chemical means. However, efficient collection of sunlight in the absorber and spectral control in the emitter are particularly challenging at high operating temperatures. This drawback has limited previous experimental demonstrations of this approach to conversion efficiencies around or below 1% (refs 9, 10, 11). Here, we report on a full solar thermophotovoltaic device, which, thanks to the nanophotonic properties of the absorber-emitter surface, reaches experimental efficiencies of 3.2%. The device integrates a multiwalled carbon nanotube absorber and a one-dimensional Si/SiO2 photonic-crystal emitter on the same substrate, with the absorber-emitter areas optimized to tune the energy balance of the device. Our device is planar and compact and could become a viable option for high-performance solar thermophotovoltaic energy conversion.

  11. Combustion powered thermophotovoltaic emitter system

    Energy Technology Data Exchange (ETDEWEB)

    McHenry, R.S. [Naval Academy, Annapolis, MD (United States). Naval Architecture, Ocean and Marine Engineering

    1995-07-01

    The US Naval Academy (USNA) has recently completed an engineering design project for a high temperature thermophotovoltaic (TPV) photon emitter. The final apparatus was to be portable, completely self contained, and was to incorporate cycle efficiency optimization such as exhaust stream recuperation. Through computer modeling and prototype experimentation, a methane fueled emitter system was designed from structural ceramic materials to fulfill the high temperature requirements necessary for high system efficiency. This paper outlines the engineering design process, discusses obstacles and solutions encountered, and presents the final design.

  12. Renewable Silica-Carbon Nanocomposite and Its Use for Reinforcing Synthetic Wood Made of Rice Straw Powders

    OpenAIRE

    Karyasa, I Wayan

    2016-01-01

    The current study was aimed to prepare and to characterize a renewable silica-carbon nanocomposite from rice straw ashes. It was purposed also to study the use of the produced nanocomposite as reinforcing material in producing a synthetic wood made of three axial blend of treated rice straw powder, phenolfrmaldehyde resin, and the nanocomposite. A simple preparation route of nanocomposite silica-carbon from rice straw was formulated containing three steps, namely pretreating of rice straw, pr...

  13. Morphology and properties of polypropylene/ethylene vinyl acetate copolymer/wood powder blend composites

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available Polypropylene (PP was blended with ethylene vinyl acetate copolymer (EVA to form PP/EVA polymer blends. Wood powder (WP was mixed into these blends at different weight fractions (50/50/0, 45/45/10, 40/40/20, 35/35/30 w/w PP/EVA/WP to form PP/EVA/WP blend composites. The morphology, as well as thermal and mechanical properties, of these composites were investigated. The scanning electron microscopy (SEM and differential scanning calorimetry (DSC results confirm the immiscibility of EVA and PP in the blends, and show that WP is primarily concentrated in the EVA phase. DSC results further show that the EVA crystallization behaviour is significantly influenced by the presence of WP. Dynamic mechanical analysis (DMA results confirm immiscibility of PP and EVA, as well as an interaction between EVA and WP. Interaction between EVA and WP was further confirmed by Fourier-Transform infrared spectroscopy (FTIR. TGA results show that the blend composite degradation was also influenced by the presence of WP.

  14. Inverted 3J Tandem Thermophotovoltaic Modules Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spire Semiconductor proposes to make an InGaAs-based three-junction (3J) tandem thermophotovoltaic (TPV) cell to utilize more of the blackbody spectrum (from a GPHS)...

  15. Super-Planckian Thermophotovoltaics Without Vacuum Gaps

    Science.gov (United States)

    Mirmoosa, M. S.; Biehs, S.-A.; Simovski, C. R.

    2017-11-01

    We introduce the concept of a thermophotovoltaic system whose emitter is separated from the photovoltaic cell by an intermediate thick slab of gallium arsenide. Owing to the engineered structure of the emitter (a multilayer structure of negative- and positive-ɛ layers) together with a high refractiveindex and transparency of the intermediate slab, we achieve a super-Planckian and frequency-selective spectrum of radiative heat transfer which is desirable for the efficient performance of thermophotovoltaic systems.

  16. Experimental study of cyclone combustion of wood powder for gas turbine applications

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksson, J.; Kallner, P. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

    1993-12-31

    The objective of the present project is to study to what extent various elements in the ash, in particular Na and K, can be separated in the first stage of a two-stage combustor, with the first stage being a separation cyclone. Mass balances for the elements in the ash are determined from the fuel flow, the char collected from the cyclone bottom and particles in the combustor outlet gas. Experiments have been carried out at atmospheric pressure for wood powder feeding rates of 5-21 kg/h. The conditions in the cyclone have been kept fuel rich. The gas outlet temperature from this stage has been varied from 750 to 1150 deg C through control of the air/fuel ratio. Second stage combustion is achieved in a separate combustor. The results show that significant separation of Na and K is possible, and that the separation is improved when the cyclone temperature is kept low. At an outlet temperature of around 800 deg C about 60% of the input alkali is found in the char residue. At 1000 deg C, only 30% is separated. Mass balances show that about 80% of the ash elements in the fuel input are identified in char and fly ash. With 60% separation of Na and K the content of these elements in the gas would be less than 7 mg/kg gas for a turbine inlet temperature of 850 deg C. The total dust load would be 30-60 mg/kg gas. Ash sticking temperature tests on bottom char and fly ash show no ash sticking up to 1040 deg C. It is therefore concluded that the ash may pass through the turbine as solid particles and cause minimal deposits or corrosion. 15 refs

  17. Solar thermophotovoltaic system using nanostructures.

    Science.gov (United States)

    Ungaro, Craig; Gray, Stephen K; Gupta, Mool C

    2015-09-21

    This paper presents results on a highly efficient experimental solar thermophotovoltaic (STPV) system using simulated solar energy. An overall power conversion efficiency of 6.2% was recorded under solar simulation. This was matched with a thermodynamic model, and the losses within the system, as well as a path forward to mitigate these losses, have been investigated. The system consists of a planar, tungsten absorbing/emitting structure with an anti-reflection layer coated laser-microtextured absorbing surface and single-layer dielectric coated emitting surface. A GaSb PV cell was used to capture the emitted radiation and convert it into electrical energy. This simple structure is both easy to fabricate and temperature stable, and contains no moving parts or heat exchange fluids.

  18. Wood

    DEFF Research Database (Denmark)

    Unterrainer, Walter

    2014-01-01

    come from? How is it harvested? How is it manufactured and treated ? How are the buildings detailed and protected against weather during construction to keep them dry and make them long-life ? In a period of climate change, forests are the last lungs of the planet to sequestrate CO2. Their global size......Wood – a sustainable building material ? For thousands of years and all over the planet, wood has been used as a building material and exciting architecture has been created in wood. The fantastic structural, physical and aesthetic properties of the material as well as the fact that wood...... is a renewable resource makes it predestinated for what is considered ´sustainable architecture´. But the reality is less linear and there are serious traps: In fact the lecture shows by examples that it is much easier to build very unsustainable buildings in wood than the other way round! Where does the wood...

  19. A Study on Tensile Behavior and Water Uptake of Wood Powder-Composites Based on Epoxy and Unsaturated Polyester Resins

    Directory of Open Access Journals (Sweden)

    Amir hossein Pirayeshfar

    2013-06-01

    Full Text Available In this study, two kinds of epoxy resins (i.e. high-viscosity and low-viscosity as well as one polyester resin (orthophthalic grade were selected and examined as pure resins and also as a polymeric matrix for producing wood-composites. In this study, tensile properties, water uptake, and degradation of samples in water were also investigated. The results show that addition of wood particles to the thermoset resins strongly impresses on their tensile behavior and water uptake. Tensile studies show that addition of wood powder improves the tensile properties of polyester resin as compared with viscosity epoxy one, although its modulus value is relatively less than that of low viscosity epoxy resin. Water uptake measurements also revealed that pure polyester resin and its related composites possess minimum water uptake and less degradation in water as compared with corresponding epoxy specimens and from which the lowest extent of materials is extracted and migrated to the water even after 50 days immersion in water.

  20. Radiative cooling for thermophotovoltaic systems

    Science.gov (United States)

    Zhou, Zhiguang; Sun, Xingshu; Bermel, Peter

    2016-09-01

    Radiative cooling has recently garnered a great deal of attention for its potential as an alternative method for photovoltaic thermal management. Here, we will consider the limits of radiative cooling for thermal management of electronics broadly, as well as a specific application to thermal power generation. We show that radiative cooling power can increase rapidly with temperature, and is particularly beneficial in systems lacking standard convective cooling. This finding indicates that systems previously operating at elevated temperatures (e.g., 80°C) can be passively cooled close to ambient under appropriate conditions with a reasonable cooling area. To examine these general principles for a previously unexplored application, we consider the problem of thermophotovoltaic (TPV) conversion of heat to electricity via thermal radiation illuminating a photovoltaic diode. Since TPV systems generally operate in vacuum, convective cooling is sharply limited, but radiative cooling can be implemented with proper choice of materials and structures. In this work, realistic simulations of system performance are performed using the rigorous coupled wave analysis (RCWA) techniques to capture thermal emitter radiation, PV diode absorption, and radiative cooling. We subsequently optimize the structural geometry within realistic design constraints to find the best configurations to minimize operating temperature. It is found that low-iron soda-lime glass can potentially cool the PV diode by a substantial amount, even to below ambient temperatures. The cooling effect can be further improved by adding 2D-periodic photonic crystal structures. We find that the improvement of efficiency can be as much as an 18% relative increase, relative to the non-radiatively cooled baseline, as well as a potentially significant improvement in PV diode lifetime.

  1. Wood

    Science.gov (United States)

    David W. Green; Robert H. White; Antoni TenWolde; William Simpson; Joseph Murphy; Robert J. Ross; Roland Hernandez; Stan T. Lebow

    2006-01-01

    Wood is a naturally formed organic material consisting essentially of elongated tubular elements called cells arranged in a parallel manner for the most part. These cells vary in dimensions and wall thickness with position in the tree, age, conditions of growth, and kind of tree. The walls of the cells are formed principally of chain molecules of cellulose, polymerized...

  2. High Operating Temperature, Radiation-Hard MIM Thermophotovoltaic Converters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spire Corporation is developing a key component for thermophotovoltaic (TPV) power technology for deep space missions. We are developing InGaAs monolithically...

  3. Efficient Thermally Stable Spectral Control Filters for Thermophotovoltaics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The feasibility of radioisotope thermophotovoltaic (RTPV) power systems has been shown. The best efficiencies reported to date for a TPV module test include front...

  4. High Operating Temperature, Radiation-Hard MIM Thermophotovoltaic Converters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spire Corporation proposes to investigate InGaAs thermophotovoltaic (TPV) cells optimized for high temperature operation (~150C) and radiation hardness against the...

  5. Thermophotovoltaic Energy Conversion in Space Nuclear Reactor Power Systems

    National Research Council Canada - National Science Library

    Presby, Andrew L

    2004-01-01

    .... This has potential benefits for space nuclear reactor power systems currently in development. The primary obstacle to space operation of thermophotovoltaic devices appears to be the low heat rejection temperatures which necessitate large radiator areas...

  6. Development of a portable thermophotovoltaic power generator

    Science.gov (United States)

    Becker, Frederick E.; Doyle, Edward F.; Shukla, Kailash

    1997-03-01

    A 150 Watt thermophotovoltaic (TPV) power generator is being developed. The technical approach taken in the design focused on optimizing the integrated performance of the primary subsystems in order to yield high energy conversion efficiency and cost effectiveness. An important aspect of the approach is the use of a selective emitter radiating to a bandgap matched photovoltaic array to minimize thermal and optical recuperation requirements, as well as the non-recoverable heat losses. For the initial prototype system, fibrous ytterbia emitters radiating in a band centered at 980 nm are matched with high efficiency silicon photoconverters. The integrated system includes a dielectric stack filter for optical energy recovery and a ceramic recuperator for thermal energy recovery. The system has been operated with air preheat temperatures up to 1350K. The design of the system and development status are presented.

  7. A Study on Tensile Behavior and Water Uptake of Wood Powder-Composites Based on Epoxy and Unsaturated Polyester Resins

    OpenAIRE

    Amir hossein Pirayeshfar; M.Mahdi Jalili; Yahya Musavi

    2013-01-01

    In this study, two kinds of epoxy resins (i.e. high-viscosity and low-viscosity) as well as one polyester resin (orthophthalic grade) were selected and examined as pure resins and also as a polymeric matrix for producing wood-composites. In this study, tensile properties, water uptake, and degradation of samples in water were also investigated. The results show that addition of wood particles to the thermoset resins strongly impresses on their tensile behavior and water uptake. Tensile studie...

  8. Thermophotovoltaic Arrays for Electrical Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Sarnoff Corporation

    2003-11-18

    Sarnoff has designed an integrated array of thermophotovoltaic (TPV) cells based on the In(Al)GaAsSb/GaSb materials system. These arrays will be used in a system to generate electrical power from a radioisotope heat source that radiates at temperatures from 700 to 1000 C. Two arrays sandwich the slab heat source and will be connected in series to build voltage. Between the arrays and the heat source is a spectral control filter that transmits above-bandgap radiation and reflects below-bandgap radiation. The goal is to generate 5 mW of electrical power at 3 V from a 700 C radiant source. Sarnoff is a leader in antimonide-based TPV cell development. InGaAsSb cells with a bandgap of 0.53 eV have operated at system conversion efficiencies greater than 17%. The system included a front-surface filter, and a 905 C radiation source. The cells were grown via organo-metallic vapor-phase epitaxy. Sarnoff will bring this experience to bear on the proposed project. The authors first describe array and cell architecture. They then present calculated results showing that about 80 mW of power can be obtained from a 700 C radiator. Using a conservative array design, a 5-V output is possible.

  9. Portable thermo-photovoltaic power source

    Science.gov (United States)

    Zuppero, Anthony C.; Krawetz, Barton; Barklund, C. Rodger; Seifert, Gary D.

    1997-01-14

    A miniature thermo-photovoltaic (TPV) device for generation of electrical power for use in portable electronic devices. A TPV power source is constructed to provide a heat source chemical reactor capable of using various fuels, such as liquid hydrocarbons, including but not limited to propane, LPG, butane, alcohols, oils and diesel fuels to generate a source of photons. A reflector dish guides misdirected photon energy from the photon source toward a photovoltaic array. A thin transparent protector sheet is disposed between the photon source and the array to reflect back thermal energy that cannot be converted to electricity, and protect the array from thermal damage. A microlens disposed between the protector sheet and the array further focuses the tailored band of photon energy from the photon source onto an array of photovoltaic cells, whereby the photon energy is converted to electrical power. A heat recuperator removes thermal energy from reactor chamber exhaust gases, preferably using mini- or micro-bellows to force air and fuel past the exhaust gases, and uses the energy to preheat the fuel and oxidant before it reaches the reactor, increasing system efficiency. Mini- or micro-bellows force ambient air through the system both to supply oxidant and to provide cooling. Finally, an insulator, which is preferably a super insulator, is disposed around the TPV power source to reduce fuel consumption, and to keep the TPV power source cool to the touch so it can be used in hand-held devices.

  10. Graphene-on-Silicon Near-Field Thermophotovoltaic Cell

    NARCIS (Netherlands)

    Svetovoy, V. B.; Palasantzas, G.

    2014-01-01

    A graphene layer on top of a dielectric can dramatically influence the ability of the material for radiative heat transfer. This property of graphene is used to improve the performance and reduce costs of near-field thermophotovoltaic cells. Instead of low-band-gap semiconductors it is proposed to

  11. Perfectly Impedance-Matched Negative Index High Temperature Selective Emission Films for Thermophotovoltaics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermophotovoltaic(TPV) energy conversion produces electrical power from heat energy in a simple, low maintenance manner ideal for certain NASA applications....

  12. Spectrally Matched Wideband Metamaterial Emitters for High Power and Efficient Thermophotovoltaic Converters, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A thermophotovoltaic (TPV) system is a promising energy conversion device that generates the electric power from short wave infrared (SWIR) thermal radiation....

  13. Recombination Processes on Low Bandgap Antimonides for Thermophotovoltaic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Saroop, Sudesh [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1999-09-01

    Recombination processes in antimonide-based (TPV) devices have been investigated using a technique, in which a Nd-YAG pulsed laser is materials for thermophotovoltaic radio-frequency (RF) photoreflectance used to excite excess carriers and the short-pulse response and photoconductivity decay are monitored with an inductively-coupled non-contacting RF probe. The system has been used to characterize surface and bulk recombination mechanisms in Sb-based materials.

  14. Polycrystalline-thin-film thermophotovoltaic cells

    Science.gov (United States)

    Dhere, Neelkanth G.

    1996-02-01

    Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto

  15. Development of Wood Apple Shell (Feronia acidissima Powder Biosorbent and Its Application for the Removal of Cd(II from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Ch. Suresh

    2014-01-01

    Full Text Available A biosorbent was prepared by using wood apple shell (WAS powder and studied its application for the removal of Cd(II from aqueous solution by a batch method. The biosorbent was characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and elemental analysis. WAS is principally made up of lignin and cellulose, containing functional groups such as alcoholic, ketonic, and carboxylic groups which can be involved in complexation reactions with Cd(II. The effect of experimental parameters like initial pH, contact time, metal ion concentration, and sorbent dose on adsorption was investigated. The optimum pH for biosorption of Cd(II onto WAS was found to be pH 5.0 and the quantitative removal of Cd(II ions was achieved in 30 min. The kinetic study showed that the biosorption process followed the pseudo-second-order rate. Experimental data were analyzed by Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. Desorption studies were carried out using HCl solution.

  16. An integrated microcombustor and photonic crystal emitter for thermophotovoltaics

    International Nuclear Information System (INIS)

    Chan, Walker R.; Stelmakh, Veronika; Joannopoulos, John D.; Celanovic, Ivan; Allmon, William R.; Waits, Christopher M.; Soljacic, Marin

    2016-01-01

    Thermophotovoltaic (TPV) energy conversion is appealing for portable millimeter- scale generators because of its simplicity, but it relies on a high temperatures. The performance and reliability of the high-temperature components, a microcombustor and a photonic crystal emitter, has proven challenging because they are subjected to 1000-1200°C and stresses arising from thermal expansion mismatches. In this paper, we adopt the industrial process of diffusion brazing to fabricate an integrated microcombustor and photonic crystal by bonding stacked metal layers. Diffusion brazing is simpler and faster than previous approaches of silicon MEMS and welded metal, and the end result is more robust. (paper)

  17. Photonic Crystal Enabled Thermophotovoltaics for a Portable Microgenerator

    Science.gov (United States)

    Chan, Walker R.; Stelmakh, Veronika; Waits, Christopher M.; Soljacic, Marin; Joannopoulos, John D.; Celanovic, Ivan

    2015-12-01

    This work presents the design and characterization of a first-of-a-kind millimeter- scale thermophotovoltaic (TPV) system using a metallic microburner, photonic crystal emitter, and low-bandgap photovoltaic (PV) cells. In our TPV system, combustion heats the emitter to incandescence and the resulting thermal radiation is converted to electricity by the low bandgap PV cells. Our motivation is to harness the high specific energy of hydrocarbon fuels at the micro- and millimeter-scale in order to meet the increasing power demands of micro robotics and portable electronics. Our experimental demonstration lays the groundwork for developing a TPV microgenerator as a viable battery replacement.

  18. Toward high performance radioisotope thermophotovoltaic systems using spectral control

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiawa, E-mail: xiawaw@mit.edu [Electrical Engineering Department, Massachusetts Institute of Technology, Cambridge, MA02139 (United States); Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, MA02139 (United States); Chan, Walker [Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, MA02139 (United States); Stelmakh, Veronika [Electrical Engineering Department, Massachusetts Institute of Technology, Cambridge, MA02139 (United States); Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, MA02139 (United States); Celanovic, Ivan [Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, MA02139 (United States); Fisher, Peter [Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, MA02139 (United States); Physics Department, Massachusetts Institute of Technology, Cambridge, MA02139 (United States)

    2016-12-01

    This work describes RTPV-PhC-1, an initial prototype for a radioisotope thermophotovoltaic (RTPV) system using a two-dimensional photonic crystal emitter and low bandgap thermophotovoltaic (TPV) cell to realize spectral control. We validated a system simulation using the measurements of RTPV-PhC-1 and its comparison setup RTPV-FlatTa-1 with the same configuration except a polished tantalum emitter. The emitter of RTPV-PhC-1 powered by an electric heater providing energy equivalent to one plutonia fuel pellet reached 950 °C with 52 W of thermal input power and produced 208 mW output power from 1 cm{sup 2} TPV cell. We compared the system performance using a photonic crystal emitter to a polished flat tantalum emitter and found that spectral control with the photonic crystal was four times more efficient. Based on the simulation, with more cell areas, better TPV cells, and improved insulation design, the system powered by a fuel pellet equivalent heat source is expected to reach an efficiency of 7.8%.

  19. Solar-Powered, Micron-Gap Thermophotovoltaics for MEO Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is an InGaAs-based, radiation-tolerant, micron-gap thermophotovoltaic (MTPV) technology. The use of a micron wide gap between the radiation...

  20. Thermophotovoltaic systems for civilian and industrial applications in Japan

    International Nuclear Information System (INIS)

    Yugami, Hiroo; Sasa, Hiromi; Yamaguchi, Masafumi

    2003-01-01

    The potential market for thermophotovoltaic (TPV) applications has been studied for civilian and industrial sectors in Japan. Comparing the performance of gas engines or turbines, as well as the underdeveloped power generation technologies such as fuel cells or chemical batteries, we have discussed the feasible application field of TPV systems to compete with those power generators. From the point of view of applicability for TPV systems in Japan, portable generators, co-generation systems and solar power plants are selected for our system analysis. The cost and performance targets of TPV systems for co-generation are also discussed by assuming a typical daily profile of electricity and hot water demands in Japanese homes. A progress report on the recent TPV research activities is given as well as a feasibility study concerning such TPV systems in Japan. (Author)

  1. Graphene-on-Silicon Near-Field Thermophotovoltaic Cell

    Science.gov (United States)

    Svetovoy, V. B.; Palasantzas, G.

    2014-09-01

    A graphene layer on top of a dielectric can dramatically influence the ability of the material for radiative heat transfer. This property of graphene is used to improve the performance and reduce costs of near-field thermophotovoltaic cells. Instead of low-band-gap semiconductors it is proposed to use graphene-on-silicon Schottky photovoltaic cells. One layer of graphene absorbs around 90% of incoming radiation and increases the heat transfer. This strong absorption is due to the excitation of plasmons in graphene, which are automatically tuned in resonance with the emitted light in the midinfrared range. The absorbed radiation excites electron-hole pairs in graphene, which are separated by the surface field induced by the Schottky barrier. For a quasimonochromatic source the generated power is one order of magnitude larger and the efficiency is on the same level as for semiconductor photovoltaic cells.

  2. Thermodynamic analysis of Thermophotovoltaic Efficiency and Power Density Tradeoffs

    Energy Technology Data Exchange (ETDEWEB)

    P.F. Baldasara; J.E. Reynolds; G.W. Charache; D.M. DePoy; C.T. Ballinger; T. Donovan; J.M. Borrego

    2000-02-22

    This report presents an assessment of the efficiency and power density limitations of thermophotovoltaic (TPV) energy conversion systems for both ideal (radiative-limited) and practical (defect-limited) systems. Thermodynamics is integrated into the unique process physics of TPV conversion, and used to define the intrinsic tradeoff between power density and efficiency. The results of the analysis reveal that the selection of diode bandgap sets a limit on achievable efficiency well below the traditional Carnot level. In addition it is shown that filter performance dominates diode performance in any practical TPV system and determines the optimum bandgap for a given radiator temperature. It is demonstrated that for a given radiator temperature, lower bandgap diodes enable both higher efficiency and power density when spectral control limitations are included. The goal of this work is to provide a better understanding of the basic system limitations that will enable successful long-term development of TPV energy conversion technology.

  3. Design and global optimization of high-efficiency thermophotovoltaic systems.

    Science.gov (United States)

    Bermel, Peter; Ghebrebrhan, Michael; Chan, Walker; Yeng, Yi Xiang; Araghchini, Mohammad; Hamam, Rafif; Marton, Christopher H; Jensen, Klavs F; Soljačić, Marin; Joannopoulos, John D; Johnson, Steven G; Celanovic, Ivan

    2010-09-13

    Despite their great promise, small experimental thermophotovoltaic (TPV) systems at 1000 K generally exhibit extremely low power conversion efficiencies (approximately 1%), due to heat losses such as thermal emission of undesirable mid-wavelength infrared radiation. Photonic crystals (PhC) have the potential to strongly suppress such losses. However, PhC-based designs present a set of non-convex optimization problems requiring efficient objective function evaluation and global optimization algorithms. Both are applied to two example systems: improved micro-TPV generators and solar thermal TPV systems. Micro-TPV reactors experience up to a 27-fold increase in their efficiency and power output; solar thermal TPV systems see an even greater 45-fold increase in their efficiency (exceeding the Shockley-Quiesser limit for a single-junction photovoltaic cell).

  4. Design and Optimization of Thermophotovoltaic System Cavity with Mirrors

    Directory of Open Access Journals (Sweden)

    Tian Zhou

    2016-09-01

    Full Text Available Thermophotovoltaic (TPV systems can convert radiant energy into electrical power. Here we explore the design of the TPV system cavity, which houses the emitter and the photovoltaic (PV cells. Mirrors are utilized in the cavity to modify the spatial and spectral distribution within. After discussing the basic concentric tubular design, two novel cavity configurations are put forward and parametrically studied. The investigated variables include the shape, number, and placement of the mirrors. The optimization objectives are the optimized efficiency and the extended range of application of the TPV system. Through numerical simulations, the relationship between the design parameters and the objectives are revealed. The results show that careful design of the cavity configuration can markedly enhance the performance of the TPV system.

  5. Operating experience of a portable thermophotovoltaic power supply

    Science.gov (United States)

    Becker, Frederick E.; Doyle, Edward F.; Shukla, Kailash

    1999-03-01

    Two configurations of man-portable thermophotovoltaic (TPV) power supplies based on Thermo Power's supported continuous fiber emitter have been designed, built, and are being tested. The systems use narrow-band, fibrous, ytterbia emitters radiating to bandgap matched silicon photovoltaic arrays with dielectric stack filters for optical energy recovery and recuperators for thermal energy recovery. The systems have been designed for operation with propane and with combustion air preheat temperatures of up to 1250 K. To operate at air preheat temperatures above the auto-ignition temperature of the fuel, a unique fuel delivery system was devised which results in the micromixing and rapid combustion of the fuel and air right in the emitter fibers. This allows the ytterbia emitter fibers to run much hotter (˜2000 K) than any of the surrounding structure.

  6. Optimization of Metamaterial Selective Emitters for Use in Thermophotovoltaic Applications

    Science.gov (United States)

    Pfiester, Nicole A.

    The increasing costs of fossil fuels, both financial and environmental, has motivated many to look into sustainable energy sources. Thermophotovoltaics (TPVs), specialized photovoltaic cells focused on the infrared range, offer an opportunity to achieve both primary energy capture, similar to traditional photovoltaics, as well as secondary energy capture in the form of waste heat. However, to become a feasible energy source, TPV systems must become more efficient. One way to do this is through the development of selective emitters tailored to the bandgap of the TPV diode in question. This thesis proposes the use of metamaterial emitters as an engineerable, highly selective emitter that can withstand the temperatures required to collect waste heat. Metamaterial devices made of platinum and a dielectric such as alumina or silicon nitride were initially designed and tested as perfect absorbers. High temperature robustness testing demonstrates the device's ability to withstand the rigors of operating as a selective emitter.

  7. Thermophotovoltaic energy conversion system having a heavily doped n-type region

    Science.gov (United States)

    DePoy, David M.; Charache, Greg W.; Baldasaro, Paul F.

    2000-01-01

    A thermophotovoltaic (TPV) energy conversion semiconductor device is provided which incorporates a heavily doped n-type region and which, as a consequence, has improved TPV conversion efficiency. The thermophotovoltaic energy conversion device includes an emitter layer having first and second opposed sides and a base layer in contact with the first side of the emitter layer. A highly doped n-type cap layer is formed on the second side of the emitter layer or, in another embodiment, a heavily doped n-type emitter layer takes the place of the cap layer.

  8. Development of micro-thermophotovoltaic power generator with heat recuperation

    International Nuclear Information System (INIS)

    Yang, W.M.; Chua, K.J.; Pan, J.F.; Jiang, D.Y.; An, H.

    2014-01-01

    Highlights: • Recuperator can significantly increase the wall temperature of micro combustor. • A prototype micro-thermophotovoltaic power generator is assembled and tested. • The output power of the micro-TPV system is increased by 83% with recuperator. - Abstract: A high and uniform wall temperature distribution is desirable for Micro-TPV system application. In this work, numerical simulation combined with experimental test is conducted to study the combustion of hydrogen–air mixture in a microcylindrical combustor with and without a heat recuperator. The results indicate that the temperature distribution along the wall of the micro combustor with a heat recuperator is more uniform and the mean wall temperature is increased by up to 123 K compared to that without a heat recuperator. A micro-TPV system is also prototyped and the performance is tested under various operating conditions, and the results indicate that the electrical power of the system is significantly increased for the micro-TPV system with a heat recuperator. When H 2 flow rate is 4.02 g/h and H 2 /air equivalence ratio is 0.8, the electrical power of the micro-TPV system with a heat recuperator is increased from 0.74 W to 1.26 W, corresponding to an increase of 70%

  9. The design and numerical analysis of tandem thermophotovoltaic cells

    International Nuclear Information System (INIS)

    Yang Hao-Yu; Liu Ren-Jun; Wang Lian-Kai; Lü You; Li Tian-Tian; Li Guo-Xing; Zhang Yuan-Tao; Zhang Bao-Lin

    2013-01-01

    In this paper, numerical analysis of GaSb =(E g = 0.72 eV)/Ga 0.84 In 0.16 As 0.14 Sb 0.86 (E g = 0.53 eV) tandem thermophotovoltaic (TPV) cells is carried out by using Silvaco/Atlas software. In the tandem cells, a GaSb p-n homojunction is used for the top cell and a GaInAsSb p-n homojunction for the bottom cell. A heavily doped GaSb tunnel junction connects the two sub-cells together. The simulations are carried out at a radiator temperature of 2000 K and a cell temperature of 300 K. The radiation photons are injected from the top of the tandem cells. Key properties of the single- and dual-junction TPV cells, including I–V characteristic, maximum output power (P max ), open-circuit voltage (V oc ), short-circuit current (I sc ), etc. are presented. The effects of the sub-cell thickness and carrier concentration on the key properties of tandem cells are investigated. A comparison of the dual-TPV cells with GaSb and GaInAsSb single junction cells shows that the P max of tandem cells is almost twice as great as that of the single-junction cells. (interdisciplinary physics and related areas of science and technology)

  10. Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

    Science.gov (United States)

    Charache, Greg W.; Baldasaro, Paul F.; Nichols, Greg J.

    1998-01-01

    A thermophotovoltaic energy conversion device and a method for making the device. The device includes a substrate formed from a bulk single crystal material having a bandgap (E.sub.g) of 0.4 eVternary or quaternary III-V semiconductor active layers.

  11. Quaternary InGaAsSb Thermophotovoltaic Diodes

    Energy Technology Data Exchange (ETDEWEB)

    MW Dashiell; JF Beausang; H Ehsani; GJ Nichols; DM Depoy; LR Danielson; P Talamo; KD Rahner; EJ Brown; SR Burger; PM Foruspring; WF Topper; PF Baldasaro; CA Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; J Li; R Martinelli; D Donetski; S Anikeev; G Belenky; S Luryi

    2006-03-09

    In{sub x}Ga{sub 1-x}As{sub y}Sb{sub 1-y} thermophotovoltaic (TPV) diodes were grown lattice-matched to GaSb substrates by Metal Organic Vapor Phase Epitaxy (MOVPE) in the bandgap range of E{sub G} = 0.5 to 0.6eV. InGaAsSb TPV diodes, utilizing front-surface spectral control filters, are measured with thermal-to-electric conversion efficiency and power density of {eta}{sub TPV} = 19.7% and PD =0.58 W/cm{sup 2} respectively for a radiator temperature of T{sub radiator} = 950 C, diode temperature of T{sub diode} = 27 C, and diode bandgap of E{sub G} = 0.53eV. Practical limits to TPV energy conversion efficiency are established using measured recombination coefficients and optical properties of front surface spectral control filters, which for 0.53eV InGaAsSb TPV energy conversion is {eta}{sub TPV} = 28% and PD = 0.85W/cm{sup 2} at the above operating temperatures. The most severe performance limits are imposed by (1) diode open-circuit voltage (VOC) limits due to intrinsic Auger recombination and (2) parasitic photon absorption in the inactive regions of the module. Experimentally, the diode V{sub OC} is 15% below the practical limit imposed by intrinsic Auger recombination processes. Analysis of InGaAsSb diode electrical performance vs. diode architecture indicate that the V{sub OC} and thus efficiency is limited by extrinsic recombination processes such as through bulk defects.

  12. Advanced Thermophotovoltaic Cells Modeling, Optimized for Use in Radioisotope Thermoelectric Generators (RTGs) for Mars and Deep Space Missions

    National Research Council Canada - National Science Library

    Davenport, Bradley

    2004-01-01

    .... This thesis examines the possible use of thermophotovoltaic (TPV) cells in RTGs. Two cells were developed and optimized for the spectrum from a 1300K blackbody that simulates the spectrum of an RTG heat source...

  13. Wood flour

    Science.gov (United States)

    Craig M. Clemons; Daniel F. Caufield

    2005-01-01

    The term “wood flour” is somewhat ambiguous. Reineke states that the term wood flour “is applied somewhat loosely to wood reduced to finely divided particles approximating those of cereal flours in size, appearance, and texture”. Though its definition is imprecise, the term wood flour is in common use. Practically speaking, wood flour usually refers to wood particles...

  14. a Study of High Efficiency Thin Thermophotovoltaic Solar Cells.

    Science.gov (United States)

    Vera, Eduardo Sobrino

    1982-05-01

    High conversion efficiency of solar energy into electrical energy is possible if the incident radiation is first absorbed by an intermediate absorber and then re-emitted onto a photovoltaic (PV) solar cell. This mode of operation is known as solar thermophotovoltaic (TPV) energy conversion. This thesis explores the limits on performance of TPV systems based on germanium in which the source temperature and the opto-electronic structure of the germanium PV cell are varied and optimized with respect to overall radiant energy conversion efficiency. The principal characteristic of the optimized high efficiency TPV germanium cells is that they are thin p-n junction solar cells which incorporate minority carrier mirrors (MCM) and optical mirrors (OM) at the front and back surfaces of the device examined. In this study, the role of MCM and OM is studied theoretically by solving the minority carrier diffusion equation in the n- and p-type quasineutral regions of the cell with the appropriate boundary conditions at the end of these regions and an appropriate minority carrier generation function. The high theoretical efficiency calculated for these thin structures derives from the simultaneous use of optical and electronic reflection. The calculations presented here determine the theoretical upper limit to TPV conversion efficiency and show the dependence of this limit on cell geometry, resistivity, surface recombination and input density. In addition, TPV systems based on more than one PV cell, each utilizing a different photovoltaically active semiconductor are also considered. A number of possible TPV systems are treated within this theoretical framework. When blackbody thermal radiation sources having temperatures in the range 1500-2000 C are considered, the upper limit efficiency is found to be about 22% for an optimum design germanium cell 90 microns thick and about 26% for a two-junction silicon-germanium tandem cell arrangement 50 and 90 microns thick, respectively

  15. Quaternary InGaAsSb Thermophotovoltaic Diode Technology

    International Nuclear Information System (INIS)

    M Dashiell; J Beausang; H Ehsani; G Nichols; D DePoy; L Danielson; P Talamo; K Rahner; E Brown; S Burger; P Fourspring; W Topper; P Baldasaro; C Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; Jizhong Li; R Martinelli; D Donetski; S Anikeev; G Belenky; S Luryl

    2005-01-01

    Thermophotovoltaic (TPV) diodes fabricated from InGaAsSb alloys lattice-matched to GaSb substrates are grown by Metal Organic Vapor Phase Epitaxy (MOVPE). 0.53eV InGaAsSb TPV diodes utilizing front-surface spectral control filters have been tested in a vacuum cavity and a TPV thermal-to-electric conversion efficiency (η TPV ) and a power density (PD) of η TPV = 19% and PD=0.58 W/cm 2 were measured for T radiator = 950 C and T diode = 27 C. Recombination coefficients deduced from minority carrier measurements and the theory reviewed in this article predict a practical limit to the maximum achievable conversion efficiency and power density for 0.53eV InGaAsSb TPV. The limits for the above operating temperatures are projected to be η TPV = 26% and PD = 0.75 W/cm 2 . These limits are extended to η TPV = 30% and PD = 0.85W/cm 2 if the diode active region is bounded by a reflective back surface to enable photon recycling and a two-pass optical path length. The internal quantum efficiency of the InGaAsSb TPV diode is close to the theoretically predicted limits, with the exception of short wavelength absorption in GaSb contact layers. Experiments show that the open circuit voltage of the 0.53eV InGaAsSb TPV diodes is not strongly dependent on the device architectures studied in this work where both N/P and P/N double heterostructure diodes have been grown with various acceptor and donor doping levels, having GaSb and AlGaAsSb confinement, and also partial back surface reflectors. Lattice matched InGaAsSb TPV diodes were fabricated with bandgaps ranging from 0.6 to 0.5eV without significant degradation of the open circuit voltage factor, quantum efficiency, or fill factor as the composition approached the miscibility gap. The key diode performance parameter which is limiting efficiency and power density below the theoretical limits in InGaAsSb TPV devices is the open circuit voltage. The open circuit voltages of state-of-the-art 0.53eV InGaAsSb TPV diode are ∼10

  16. Treatment of a BTo-X-contaminated gas stream with a biotrickling filter inoculated with microbes bound to a wheat bran/red wood powder/diatomaceous earth carrier.

    Science.gov (United States)

    Chen, Jian M; Zhu, Run Y; Yang, Wei B; Zhang, Li L

    2010-11-01

    Microbes bound to a wheat bran/red wood powder/diatomaceous earth carrier were used as inoculants for a biotrickling filter (BTF) for treating gases contaminated with a mixture of benzene, toluene, and o-xylene (BTo-X). An overall removal efficiency of more than 87.9% was achieved after a start-up period of as low as 4days. At BTo-X loading rates (LRs) below 60.0g/m(3)h, the BTF's performance was similar for EBRTs of 90, 60, 45 and 30s with an elimination capacity (EC) almost approaching the LR; stable REs above 91.3% for benzene and toluene and above 82.8% for o-xylene were achieved. A maximum EC of 97.7g/m(3)h was obtained at inlet load of 146.4g/m(3)h. The mass ratio of carbon dioxide produced to the BTo-X removed was approximately 2.62, which confirmed complete degradation of BTo-X. The results demonstrate that microbes bound to a solid carrier can be an alternative to traditional liquid inoculums applied in BTFs and highlight their potential applicability to BTF technologies. Copyright 2010 Elsevier Ltd. All rights reserved.

  17. Quaternary InGaAsSb Thermophotovoltaic Diode Technology

    Energy Technology Data Exchange (ETDEWEB)

    M Dashiell; J Beausang; H Ehsani; G Nichols; D DePoy; L Danielson; P Talamo; K Rahner; E Brown; S Burger; P Fourspring; W Topper; P Baldasaro; C Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; Jizhong Li; R Martinelli; D Donetski; S Anikeev; G Belenky; S Luryl

    2005-01-26

    Thermophotovoltaic (TPV) diodes fabricated from InGaAsSb alloys lattice-matched to GaSb substrates are grown by Metal Organic Vapor Phase Epitaxy (MOVPE). 0.53eV InGaAsSb TPV diodes utilizing front-surface spectral control filters have been tested in a vacuum cavity and a TPV thermal-to-electric conversion efficiency ({eta}{sub TPV}) and a power density (PD) of {eta}{sub TPV} = 19% and PD=0.58 W/cm{sup 2} were measured for T{sub radiator} = 950 C and T{sub diode} = 27 C. Recombination coefficients deduced from minority carrier measurements and the theory reviewed in this article predict a practical limit to the maximum achievable conversion efficiency and power density for 0.53eV InGaAsSb TPV. The limits for the above operating temperatures are projected to be {eta}{sub TPV} = 26% and PD = 0.75 W/cm{sup 2}. These limits are extended to {eta}{sub TPV} = 30% and PD = 0.85W/cm{sup 2} if the diode active region is bounded by a reflective back surface to enable photon recycling and a two-pass optical path length. The internal quantum efficiency of the InGaAsSb TPV diode is close to the theoretically predicted limits, with the exception of short wavelength absorption in GaSb contact layers. Experiments show that the open circuit voltage of the 0.53eV InGaAsSb TPV diodes is not strongly dependent on the device architectures studied in this work where both N/P and P/N double heterostructure diodes have been grown with various acceptor and donor doping levels, having GaSb and AlGaAsSb confinement, and also partial back surface reflectors. Lattice matched InGaAsSb TPV diodes were fabricated with bandgaps ranging from 0.6 to 0.5eV without significant degradation of the open circuit voltage factor, quantum efficiency, or fill factor as the composition approached the miscibility gap. The key diode performance parameter which is limiting efficiency and power density below the theoretical limits in InGaAsSb TPV devices is the open circuit voltage. The open circuit voltages of

  18. Analysis of solar thermophotovoltaic test data from experiments performed at McDonnell Douglas

    Energy Technology Data Exchange (ETDEWEB)

    Stone, K.W.; Kusek, S.M.; Drubka, R.E. [McDonnell Douglas, 5301 Bolsa Avenue, Huntington Beach, California 92647 (United States); Fay, T.D. [21911 Bacalar, Mission Viejo, California 92692 (United States)

    1995-01-05

    Solar thermophotovoltaic power systems offer potentially high system efficiency for solar energy to electrical energy conversion and attractive system advantages. McDonnell Douglas Corporation (MDC) has been investigating this technology for both space and terrestrial applications for several years. A testbed prototype was designed, built, and tested on a 90 kW{sub t} dish concentrator at the MDA solar test facility. Twelve experiments were conducted with absorber temperatures in excess of 1300 {degree}C being achieved using only a fraction of the reflected power from the 90 kW{sub t} dish concentrator. This paper discusses the solar thermophotovoltaic testbed prototype unit, test data, and presents an analysis of the unit`s performance. A combination of analytical analysis and test data is used to obtain an understanding of the system and subsystem performance. The preliminary results of these tests and analysis indicate a solar thermophotovoltaic power system can achieve high system performance. Furthermore, system demonstrations are possible utilizing a combination of current off-the-shelf hardware components and components currently being tested in laboratories. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  19. Performance characteristics and parametric choices of a solar thermophotovoltaic cell at the maximum efficiency

    International Nuclear Information System (INIS)

    Dong, Qingchun; Liao, Tianjun; Yang, Zhimin; Chen, Xiaohang; Chen, Jincan

    2017-01-01

    Graphical abstract: The overall model of the solar thermophotovoltaic cell (STPVC) composed of an optical lens, an absorber, an emitter, and a photovoltaic (PV) cell with an integrated back-side reflector is updated to include various irreversible losses. - Highlights: • A new model of the irreversible solar thermophotovoltaic system is proposed. • The material and structure parameters of the system are considered. • The performance characteristics at the maximum efficiency are revealed. • The optimal values of key parameters are determined. • The system can obtain a large efficiency under a relative low concentration ratio. - Abstract: The overall model of the solar thermophotovoltaic cell (STPVC) composed of an optical lens, an absorber, an emitter, and a photovoltaic (PV) cell with an integrated back-side reflector is updated to include various irreversible losses. The power output and efficiency of the cell are analytically derived. The performance characteristics of the STPVC at the maximum efficiency are revealed. The optimum values of several important parameters, such as the voltage output of the PV cell, the area ratio of the absorber to the emitter, and the band-gap of the semiconductor material, are determined. It is found that under the condition of a relative low concentration ratio, the optimally designed STPVC can obtain a relative large efficiency.

  20. Tannins in tropical woods

    Energy Technology Data Exchange (ETDEWEB)

    Doat, J.

    1978-01-01

    A preliminary study was made of the chemistry of pyrogallol- and catecholtannins, their general properties and methods of extraction and determination. Three methods of estimation - Lowenthal, powdered hide and spectrophotometry - were compared using two control solutions, four samples of wood and one of bark. Using the empirical powdered hide method, tannins of both types were estimated in wood and bark of various tropical species (some separately and some as a mixture), Moroccan oaks (Quercus suber and Q. ilex), and European oak 9Q. petraea). Further tests were made on the wood and bark of the two mangrove species, Rhizophora mangle and R. racemosa, by subjecting them to successive extraction with a range of solvents. None of the woods tested had as much as the 10% of tannins considered necessary in economic sources. The bark of the two mangroves, of Eucalyptus urophylla and of Prosopis africana had tannin contents over 10% and the latter two species had very favorable tannin/non-tannin ratios. All the tropical species, with the probable exception of E. urophylla, had only catecholtannins. Only the oaks and E. urophylla bark gave positive results when tested for gallotannins.

  1. Wood Dust

    Science.gov (United States)

    Learn about wood dust, which can raise the risk of cancers of the paranasal sinuses and nasal cavity. High amounts of wood dust are produced in sawmills, and in the furniture-making, cabinet-making, and carpentry industries.

  2. Wood preservation

    Science.gov (United States)

    Rebecca E. Ibach

    2003-01-01

    When wood is exposed to various environmental conditions, many degradation reactions (biological, ultraviolet, mechanical, moisture, and chemical) can occur. To protect wood from biological degradation, chemical preservatives are applied by nonpressure or pressure treatment. Penetration and retention of a chemical depend upon the wood species and the amount of...

  3. Sinterable powders

    International Nuclear Information System (INIS)

    Zanghi, J.S.; Kasprzyk, M.R.

    1979-01-01

    A description is given of sinterable powders and methods of producing sintered products using such powders. The powders consist of (a) a particulate ceramic material, e.g. SiC, having specified particle size and surface area; (b) a carbon source material, e.g. sugar or a phenol-formaldehyde resin; and (c) a residue from a solution of H 3 BO 3 , B 2 O 3 , or mixtures of these as sintering aid. (U.K.)

  4. Examination of thermophotovoltaic GaSb cell technology in low and medium temperatures waste heat

    Science.gov (United States)

    Utlu, Z.; Önal, B. S.

    2018-02-01

    In this study, waste heat was evaluated and examined by means of thermophotovoltaic systems with the application of energy production potential GaSb cells. The aim of our study is to examine GaSb cell technology at low and medium temperature waste heat. The evaluation of the waste heat to be used in the system is designed to be used in the electricity, industry and iron and steel industry. Our work is research. Graphic analysis is done with Matlab program. The low and medium temperature waste heat graphs applied on the GaSb cell are in the results section. Our study aims to provide a source for future studies.

  5. Performance evaluation of thermophotovoltaic GaSb cell technology in high temperature waste heat

    Science.gov (United States)

    Utlu, Z.; Önal, B. S.

    2018-02-01

    In this study, waste heat was evaluated and examined by means of thermophotovoltaic systems with the application of energy production potential GaSb cells. The aim of our study is to examine GaSb cell technology at high temperature waste heat. The evaluation of the waste heat to be used in the system is designed to be used in the electricity, industry and iron and steel industry. Our work is research. Graphic analysis is done with Matlab program. The high temperature waste heat graphs applied on the GaSb cell are in the results section. Our study aims to provide a source for future studies.

  6. Development and characterization of a rare earth emitter for a thermophotovoltaic power generator

    Energy Technology Data Exchange (ETDEWEB)

    Durisch, W.; Panitz, J.C. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Energy conversion based on thermophotovoltaic (TPV) methods has recently attracted renewed interest. Efforts at PSI are directed towards the development of a modular TPV system based on existing technology to demonstrate the feasibility of this method. Here, we report first results obtained with a prototype TPV generator based upon a modified rare earth emitter, a heat reflecting filter and commercial silicon solar cells. The preparation of the modified emitter is described, and first results of spectroscopic and electrical characterization of the TPV system are presented. The introduction of the modified emitter leads to an efficiency gain of 30-40%. (author) 3 figs., 4 refs.

  7. Hybrid Back Surface Reflector GaInAsSb Thermophotovoltaic Devices

    International Nuclear Information System (INIS)

    RK Huang; CA Wang; MK Connors; GW Turner; M Dashiell

    2004-01-01

    Back surface reflectors have the potential to improve thermophotovoltaic (TPV) device performance though the recirculation of infrared photons. The ''hybrid'' back-surface reflector (BSR) TPV cell approach allows one to construct BSRs for TPV devices using conventional, high efficiency, GaInAsSb-based TPV material. The design, fabrication, and measurements of hybrid BSR-TPV cells are described. The BSR was shown to provide a 4 mV improvement in open-circuit voltage under a constant shortcircuit current, which is comparable to the 5 mV improvement theoretically predicted. Larger improvements in open-circuit voltage are expected in the future with materials improvements

  8. Wood composites

    Science.gov (United States)

    Lars Berglund; Roger M. Rowell

    2005-01-01

    A composite can be defined as two or more elements held together by a matrix. By this definition, what we call “solid wood” is a composite. Solid wood is a three-dimensional composite composed of cellulose, hemicelluloses and lignin (with smaller amounts of inorganics and extractives), held together by a lignin matrix. The advantages of developing wood composites are (...

  9. (YSZ) powders

    Indian Academy of Sciences (India)

    Unknown

    Keywords. YSZ powder; dispersion behaviour; grindability. 1. Introduction. During the synthesis of oxide powders by solution based techniques (e.g. solution combustion, decomposition of metal nitrates, precipitation etc), agglomerates of fine crystallites of the precursors or oxides form and their size vary up to many microns.

  10. Oil Uptake Percentage in Oil-Heat-Treated Wood, its Determination by Soxhlet Extraction, and its Effects on Wood Compression Strength Parallel to the Grain

    OpenAIRE

    Dali Cheng; Lijun Chen; Shenxue Jiang; Qisheng Zhang

    2013-01-01

    Oil heat treatment can effectively improve the dimensional stability and bio-durability of wood. However, the characteristics of high oil uptake (50 percent or higher) and high susceptibility to leaching from wood have an adverse effect on subsequent manufacturing processes of wood product and production costs. A solvent extraction (100% ethanol) process was used to extract the surplus oil from the treated wood. Because the making of powder specimens from high oil uptake wood would result in ...

  11. Thermophotovoltaic (TPV) technology development. Final report, May 15, 1995--December 1, 1995

    International Nuclear Information System (INIS)

    1995-01-01

    This program information release (PIR) summarizes work performed under Task Order Contract SF17787, Task Order 18: Thermophotovoltaic Technology Development, sponsored by the U.S. Department of Energy. The period of performance was 15 May 1995 to 1 December 1995. Under this task order, a system model for a thermophotovoltaic (MV) converter was implemented and used to compare a conceptual design for an advanced quaternary III-V cell with integral filter with results previously published for a binary GaSb cell with a freestanding filter. Model results were used to assess the merits of TPV conversion for meeting various levels of space power requirements, including low to medium power isotope applications and high-power reactor applications. A TPV cell development program was initiated to determine the feasibility of fabricating quaternary III-V cells by molecular beam epitaxy. Lastly, a conceptual design was completed for a low-cost demonstration system to test the performance of TPV converters at a multi-cell, sub-system level. The results of these efforts are reported briefly in an executive summary, then in somewhat more detail as a final briefing section in which charts have been reproduced. Additional technical detail is provided in the appendices

  12. Optimization of spectrally selective Si/SiO2 based filters for thermophotovoltaic devices

    Science.gov (United States)

    Khosroshahi, Farhad Kazemi; Ertürk, Hakan; Pınar Mengüç, M.

    2017-08-01

    Design of a spectrally selective filter based on one-dimensional Si/SiO2 layers is considered for improved performance of thermo-photovoltaic devices. Spectrally selective filters transmit only the convertible radiation from the emitter as non-convertible radiation leads to a reduction in cell efficiency due to heating. The presented Si/SiO2 based filter concept reflects the major part of the undesired range back to the emitter to minimize energy required for the process and it is adaptable to different types of cells and emitters with different temperatures since its cut-off wavelength can be tuned. While this study mainly focuses on InGaSb based thermo-photovoltaic cell, Si, GaSb, and Ga0.78In0.22As0.19Sb0.81 based cells are also examined. Transmittance of the structure is predicted by rigorous coupled wave approach. Genetic algorithm, which is a global optimization method, is used to find the best possible filter structure by considering the overall efficiency as an objective function that is maximized. The simulations show that significant enhancement in the overall system and device efficiency is possible by using such filters with TPV devices. The methodology described in this paper allows for an improved filter design procedure for selected applications.

  13. Numerical and Experimental Investigation on a Thermo-Photovoltaic Module for Higher Efficiency Energy Generation

    Science.gov (United States)

    Karami-Lakeh, Hossein; Hosseini-Abardeh, Reza; Kaatuzian, Hassan

    2017-05-01

    One major problem of solar cells is the decrease in efficiency due to an increase in temperature when operating under constant irradiation of solar energy. The combination of solar cell and a thermoelectric generator is one of the methods proposed to solve this problem. In this paper, the performance of thermo-photovoltaic system is studied experimentally as well as through numerical simulation. In the experimental part, design, manufacture and test of a novel thermo-photovoltaic system assembly are presented. Results of the assembled system showed that with reduction of one degree (Centigrade) in the temperature of solar cell under investigation, and about 0.2 % increase in the efficiency will be obtained in comparison with given efficiency at that specified temperature. The solar cell in a hybrid-assembled system under two cooling conditions (air cooling and water cooling) obtained an efficiency of 8 % and 9.5 %, respectively, while the efficiency of a single cell under the same radiation condition was 6 %. In numerical simulation part, photo-thermoelectric performance of system was analyzed. Two methods for evaluation of thermoelectric performance were used: average properties and finite element method. Results of simulation also demonstrate an increase in solar cell efficiency in the combined system in comparison with that of the single cell configuration.

  14. A Study on the Effect of Plasma Treatment for Waste Wood Biocomposites

    Directory of Open Access Journals (Sweden)

    MiMi Kim

    2013-01-01

    Full Text Available The surface modification of wood powder by atmospheric pressure plasma treatment was investigated. The composites were manufactured using wood powder and polypropylene (wood powder: polypropylene = 55 wt% : 45 wt%. Atmospheric pressure plasma treatment was applied under the condition of 3 KV, 17±1 KHz, 2 g/min. Helium was used as the carrier gas and hexamethyl-disiloxane (HMDSO as the monomer to modify the surface property of the waste wood biocomposites by plasma polymerization. The tensile strengths of untreated waste wood powder (W3 and single species wood powder (S3 were about 18.5 MPa and 21.5 MPa while those of plasma treated waste wood powder (PW3 and plasma treated single species wood powder (PS3 were about 21.2 MPa and 23.4 MPa, respectively. Tensile strengths of W3 and S3 were improved by 14.6% and 8.8%, respectively. From the analyses of mechanical properties and morphology, we conclude that the interfacial bonding of polypropylene and wood powder can be improved by atmospheric pressure plasma treatment.

  15. Wood preservation

    Science.gov (United States)

    Kevin Archer; Stan Lebow

    2006-01-01

    Wood preservation can be interpreted to mean protection from fire, chemical degradation, mechanical wear, weathering, as well as biological attack. In this chapter, the term preservation is applied more restrictively to protection from biological hazards.

  16. Toxicological and histopathological effects of cheese wood, Alstonia ...

    African Journals Online (AJOL)

    Toxicological and histopathological effects of cheese wood, Alstonia boonei de wild stem bark powder used as cowpea protectant against cowpea bruchid, Callosobruchus maculatu (Fab.) [coleoptera: chrysomelidae] on albino rats.

  17. Performance analysis of near-field thermophotovoltaic devices considering absorption distribution

    International Nuclear Information System (INIS)

    Park, K.; Basu, S.; King, W.P.; Zhang, Z.M.

    2008-01-01

    This paper elucidates the energy transfer and conversion processes in near-field thermophotovoltaic (TPV) systems, considering local radiation absorption and photocurrent generation in the TPV cell. Radiation heat transfer in a multilayered structure is modeled using the fluctuation-dissipation theorem, and the electric current generation is evaluated based on the photogeneration and recombination of electron-hole pairs in different regions of the TPV cell. The effects of near-field radiation on the photon penetration depth, photocurrent generation, and quantum efficiency are examined in the spectral region of interest. The detailed analysis performed in the present work demonstrates that, while the near-field operation can enhance the power throughput, the conversion efficiency is not much improved and may even be reduced. Subsequently, a modified design of near-field TPV systems is proposed to improve the efficiency

  18. Selection of emitter material for application on a radioisotope thermophotovoltaic (RTPV) power system

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, D.P.; Frohlich, N.D.; Koehler, F.A.; Ruhkamp, J.D.; Miller, R.G.; McDougal, J.R.; Pugh, B.K.; Barklay, C.D.; Howell, E.I. [EGG Mound Applied Technologies Building 88, P.O. Box 3000 Miamisburg, Ohio45343 (United States)

    1997-01-01

    Radioisotope Thermophotovoltaic (RTPV) power systems are being considered for long duration space missions due to their predicted high thermal to electrical conversion efficiencies. One critical aspect of these power systems is the selection of an appropriate emitter material which will efficiently radiate the thermal energy generated by the heat source to the photovoltaics. The photovoltaics are {open_quotes}tuned{close_quotes} to convert the infrared wavelengths radiated by the emitter into electrical energy. The emphasis of this paper is on the selection and optimization of an appropriate emitter material which would meet all of the mission requirements. A Kepner Tregoe analysis was performed in order to rank the various candidate refractory materials in relationship to their physical and chemical properties. The results of the analysis and material recommendations are discussed. {copyright} {ital 1997 American Institute of Physics.}

  19. Graphene-assisted Si-InSb thermophotovoltaic system for low temperature applications.

    Science.gov (United States)

    Lim, Mikyung; Jin, Seokmin; Lee, Seung S; Lee, Bong Jae

    2015-04-06

    The present work theoretically analyzes the performance of the near-field thermophotovoltaic (TPV) energy conversion device for low temperature applications (Tsource ∼ 500 K). In the proposed TPV system, doped Si is employed as the source because its optical property can be readily tuned by changing the doping concentration, and InSb is selected as a TPV cell because of its low bandgap energy (0.17 eV). In order to enhance the near-field thermal radiation between the source and the TPV cell, monolayer of graphene is coated on the cell side so that surface plasmon can play a critical role in heat transfer. It is found that monolayer of graphene can significantly enhance the power throughput by 30 times and the conversion efficiency by 6.1 times compared to the case without graphene layer. The resulting maximum conversion efficiency is 19.4% at 10-nm vacuum gap width.

  20. Design of broadband absorber using 2-D materials for thermo-photovoltaic cell application

    Science.gov (United States)

    Agarwal, Sajal; Prajapati, Y. K.

    2018-04-01

    Present study is done to analyze a nano absorber for thermo-photovoltaic cell application. Optical absorbance of two-dimensional materials is exploited to achieve high absorbance. It is found that few alternating layers of graphene/transition metal dichalcogenide provide high absorbance of electromagnetic wave in visible as well as near infrared region. Four transition metal dichalcogenides are considered and found that most of these provide perfect absorbance for almost full considered wavelength range i.e. 200-1000 nm. Demonstrated results confirm the extended operating region and improved absorbance of the proposed absorber in comparison to the existing absorbers made of different materials. Further, absorber performance is improved by using thin layers of gold and chromium. Simple geometry of the proposed absorber also ensures easy fabrication.

  1. Development of a small air-cooled ``midnight sun'' thermophotovoltaic electric generator

    Science.gov (United States)

    Fraas, Lewis M.; Xiang, Huang Han; Hui, She; Ferguson, Luke; Samaras, John; Ballantyne, Russ; Seal, Michael; West, Ed

    1996-02-01

    A natural gas fired thermophotovoltaic generator using infrared-sensitive GaSb cells and a silicon carbide emitter is described. The emitter is designed to operate at 1400 °C. Twelve GaSb receivers surround the emitter. Each receiver contains a string of series connected cells. Special infrared filters are bonded to each cell. These filters transmit short wavelength useful IR to the cells while reflecting longer wavelength IR back to the emitter. Combustion air is supplied to the burner through a counterflow heat exchanger where the air is preheated by the exhaust from the burner. The unit is air cooled and designed to produce approximately 100 Watts of electric power.

  2. Effects of major parameters on micro-combustion for thermophotovoltaic energy conversion

    International Nuclear Information System (INIS)

    Pan, J.F.; Huang, J.; Li, D.T.; Yang, W.M.; Tang, W.X.; Xue, H.

    2007-01-01

    For a micro-thermophotovoltaic (TPV) energy conversion device, high surface to volume ratio in the micro-combustor provides a great potential to achieve high surface radiation power output per unit energy input. This work investigated experimentally the effects of three major parameters on micro-combustion, namely hydrogen to oxygen mixing ratio, nozzle to combustor diameter ratio, and wall thickness to combustor diameter ratio. The results show that the high average wall temperature can be achieved at slightly oxygen rich mixing ratios. Nozzle to combustor diameter ratio affects both the magnitude and uniformity of wall temperature distribution. The newly designed thin wall combustor which yields a reduction of axial heat conduction loss is able to increase wall temperature more than 150 K. Optimized design of these parameters will have significant impact on the enhancement of radiation heat output in micro-TPV energy conversion

  3. Wood handbook : wood as an engineering material

    Science.gov (United States)

    Robert J. Ross; Forest Products Laboratory. USDA Forest Service.

    2010-01-01

    Summarizes information on wood as an engineering material. Presents properties of wood and wood-based products of particular concern to the architect and engineer. Includes discussion of designing with wood and wood-based products along with some pertinent uses.

  4. Parametric characteristics of a solar thermophotovoltaic system at the maximum efficiency

    International Nuclear Information System (INIS)

    Liao, Tianjun; Chen, Xiaohang; Yang, Zhimin; Lin, Bihong; Chen, Jincan

    2016-01-01

    Graphical abstract: A model of the far-field TPVC driven by solar energy, which consists of an optical concentrator, an absorber, an emitter, and a PV cell and is simply referred as to the far-field STPVS. - Highlights: • A model of the far-field solar thermophotovoltaic system (STPVS) is established. • External and internal irreversible losses are considered. • The maximum efficiency of the STPVS is calculated. • Optimal values of key parameters at the maximum efficiency are determined. • Effects of the concentrator factor on the performance of the system are discussed. - Abstract: A model of the solar thermophotovoltaic system (STPVS) consisting of an optical concentrator, a thermal absorber, an emitter, and a photovoltaic (PV) cell is proposed, where the far-field thermal emission between the emitter and the PV cell, the radiation losses from the absorber and emitter to the environment, the reflected loss from the absorber, and the finite-rate heat exchange between the PV cell and the environment are taken into account. Analytical expressions for the power output of and overall efficiency of the STPVS are derived. By solving thermal equilibrium equations, the operating temperatures of the emitter and PV cell are determined and the maximum efficiency of the system is calculated numerically for given values of the output voltage of the PV cell and the ratio of the front surface area of the absorber to that of the emitter. For different bandgaps, the maximum efficiencies of the system are calculated and the corresponding optimum values of several operating parameters are obtained. The effects of the concentrator factor on the optimum performance of the system are also discussed.

  5. Coal and wood fuel for electricity production: An environmentally sound solution for waste and demolition wood

    Energy Technology Data Exchange (ETDEWEB)

    Penninks, F.W.M. [EPON, Zwolle (Netherlands)

    1997-12-31

    Waste wood from primary wood processing and demolition presents both a problem and a potential. If disposed in landfills, it consumes large volumes and decays, producing CH{sub 4}, CO{sub 2} and other greenhouse gases. As an energy source used in a coal fired power plant it reduces the consumption of fossil fuels reducing the greenhouse effect significantly. Additional advantages are a reduction of the ash volume and the SO{sub 2} and NO{sub x} emissions. The waste wood requires collection, storage, processing and burning. This paper describes a unique project which is carried out in the Netherlands at EPON`s Gelderland Power Plant (635 MW{sub e}) where 60 000 tonnes of waste and demolition wood will be used annually. Special emphasis is given to the processing of the powdered wood fuel. Therefore, most waste and demolition wood can be converted from an environmental liability to an environmental and economic asset. (author)

  6. Coal and wood fuel for electricity production: an environmentally sound solution for waste and demolition wood

    Energy Technology Data Exchange (ETDEWEB)

    Penninks, F.W.; Zonneveld, N. [nv EPON, Zwolle (Germany)

    1995-12-31

    Waste wood from primary wood processing and demolition presents both a problem and potential. If disposed of in land fills, it consumes large volumes and decays, producing CH{sub 4}, CO{sub 2} and other greenhouse gases. As an energy source used in a coal fired power plant it reduces the consumption of fossil fuels reducing the greenhouse effect significantly. Additional advantages are a reduction of the ash volume and the SO{sub 2} and NO{sub x} emissions. The waste wood requires collection, storage, processing and burning. This paper describes an unique project which is carried out in the Netherlands at EPON`s Gelderland Power Plant (635 MWe) where 60,000 tonnes of waste and demolition wood will be used yearly. Special emphasis is given to the processing of the powdered wood fuel. Therefore, most waste and demolition wood can be converted from a environmental liability to an environmental and economic asset.

  7. Powder Diffraction

    Science.gov (United States)

    Hart, Michael

    The importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer1,2 in Germany and, quite independently, by Hull3,4 in the United States of America. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the, first period, until the- mid-1940's. applications were and developed covering broad categories of materials including inorganic materials, minerals, cerarffics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated5. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish6 and by Langford and Loudr7. By 1980 there were probably 10000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation8-10. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments11.

  8. Powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Hart, M.

    1995-12-31

    the importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940`s, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments.

  9. Powder diffraction

    International Nuclear Information System (INIS)

    Hart, M.

    1995-01-01

    The importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940's, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments

  10. Wood as an adherend

    Science.gov (United States)

    Bryan H. River; Charles B. Vick; Robert H. Gillespie

    1991-01-01

    Wood is a porous, permeable, hygroscopic, orthotropic, biological composite material of extreme chemical diversity and physical intricacy. Table 1.1 provides an overview of the may variables, including wood variables, that bear on the bonding and performance of wood in wood joints and wood-based materials. Of particular note is the fact that wood properties vary...

  11. Characterization of wood-based molding bonded with citric acid

    OpenAIRE

    Umemura, Kenji; Ueda, Tomohide; Kawai, Shuichi

    2012-01-01

    The wood-based moldings were fabricated by using only citric acid as an adhesive. The mechanical properties, water resistances, thermal properties and chemical structure were investigated. Wood powder obtained from Acacia mangium was mixed with citric acid under certain weight ratios (0-40 wt%), and each powder mixture was molded using two types of metal molds at 200 °C and 4MPa for 10 min. The modulus of rupture (MOR) and the modulus of elasticity (MOE) values of the wood-based molding conta...

  12. Experimental and theoretical analysis of cell module output performance for a thermophotovoltaic system

    International Nuclear Information System (INIS)

    Xu, Xiaojie; Ye, Hong; Xu, Yexin; Shen, Mingrong; Zhang, Xiaojing; Wu, Xi

    2014-01-01

    Highlights: • An accurate theoretical model for thermophotovoltaic system is constructed. • Parallel connected module is superior if radiator temperature is uneven. • Series connected module is superior if cell temperature is uneven. • Short circuit current of series module rises when the shunt resistance decreases. • Fill factor is not always accurate to evaluate the module performance. - Abstract: An experimental thermophotovoltaic (TPV) system with a cylindrical-geometry radiator was established to test the output performances of modules under different conditions. The results demonstrate that the output performance of a cell module decreases when the combustion power increases because of the uneven temperature of the radiator or cells. On this basis, a theoretical model for a TPV system was constructed to compare the performance under different conditions of the series-connected (SC) module and the parallel-connected (PC) module, and was verified by the experimental results. The influences of the temperature gradient of the radiator or the cell module, and the series and shunt resistance of the TPV cell on the module performance were analyzed in detail. The results demonstrate that the PC module can effectively reduce the mismatch loss of output power caused by the uneven radiator temperature. The PC module, for instance, has a maximum output power of 2.54 times higher than that of the SC module when the radiator temperature difference is 500 K. However, the output performance of the module connected in series is superior to the PC module while the cell temperature is non-uniform. The output power of the SC module is 9.93% higher than that of the PC module at the cell temperature difference of 125 K. The short circuit current of the SC module is sensitive to the series and shunt resistance if the radiator temperature distribution is non-uniform. As the shunt resistance falls from ∞ to 0.5 Ω, the current varies from 1.757 A to 4.488 A when the

  13. Significance of wood extractives for wood bonding.

    Science.gov (United States)

    Roffael, Edmone

    2016-02-01

    Wood contains primary extractives, which are present in all woods, and secondary extractives, which are confined in certain wood species. Extractives in wood play a major role in wood-bonding processes, as they can contribute to or determine the bonding relevant properties of wood such as acidity and wettability. Therefore, extractives play an immanent role in bonding of wood chips and wood fibres with common synthetic adhesives such as urea-formaldehyde-resins (UF-resins) and phenol-formaldehyde-resins (PF-resins). Extractives of high acidity accelerate the curing of acid curing UF-resins and decelerate bonding with alkaline hardening PF-resins. Water-soluble extractives like free sugars are detrimental for bonding of wood with cement. Polyphenolic extractives (tannins) can be used as a binder in the wood-based industry. Additionally, extractives in wood can react with formaldehyde and reduce the formaldehyde emission of wood-based panels. Moreover, some wood extractives are volatile organic compounds (VOC) and insofar also relevant to the emission of VOC from wood and wood-based panels.

  14. Coal and wood fuel for electricity production: an environmentally sound solution for waste and demolition wood

    Energy Technology Data Exchange (ETDEWEB)

    Penninks, F.W.; Zonneveld, N. [nv EPON, Zwolte (Netherlands)

    1997-12-31

    Waste wood from primary wood processing and demolition presents both a problem and potential. If disposed of in land-fills, it consumes large volumes and decays, producing CH{sub 4}, CO{sub 2} and other greenhouse gases. As an energy source used in a coal fired power plant it reduces the consumption of fossil fuels reducing the greenhouse effect significantly. Additional advantages are a reduction of the ash volume and the SO{sub 2} and NO{sub x} emissions. The waste wood requires collection, storage, processing and burning. This paper describes a unique project which is carried out in the Netherlands at EPON`s Gelderland Power Plant (635 MWe) where 60,000 tonnes of waste and demolition wood will be used yearly. Special emphasis is given to the processing of the powdered wood fuel. 1 fig., 5 tabs.

  15. Powder technology

    International Nuclear Information System (INIS)

    Agueda, Horacio

    1989-01-01

    Powder technology is experiencing nowadays a great development and has broad application in different fields: nuclear energy, medicine, new energy sources, industrial and home artifacts, etc. Ceramic materials are of daily use as tableware and also in the building industry (bricks, tiles, etc.). However, in machine construction its utilization is not so common. The same happens with metals: powder metallurgy is employed less than traditional metal forming techniques. Both cases deal with powder technology and the forming techniques as far as the final consolidation through sintering processes are very similar. There are many different methods and techniques in the forming stage: cold-pressing, slip casting, injection molding, extrusion molding, isostatic pressing, hot-pressing (which involves also the final consolidation step), etc. This variety allows to obtain almost any desired form no matter how complex it could be. Some applications are very specific as in the case of UO 2 pellets (used as nuclear fuels) but with the same technique and other materials, it is possible to manufacture a great number of different products. This work shows the characteristics and behaviour of two magnetic ceramic materials (ferrites) fabricated in the laboratory of the Applied Research Division of the Bariloche Atomic Center for different purposes. Other materials and products made with the same method are also mentioned. Likewise, densities and shrinkage obtained by different methods of forming (cold-pressing, injection molding, slip casting and extrusion molding) using high-purity alumina (99.5% Al 2 O 3 ). Finally, different applications of such methods are given. (Author) [es

  16. Mechanical Activation of Wood for Adhesive-free board Production

    Science.gov (United States)

    Ermolin, V. N.; Bayandin, M. A.; Kazitsin, S. N.

    2016-11-01

    This paper proposes to use hydrodynamic treatment of wood for the manufacture of wood-based panels from sawdust without using adhesive materials. It was found that such a treatment of wood particles (sawdust, dust, wood powder) allows producing panels with high physical-mechanical properties and water resistance. It is proved that the hydrodynamic treatment allows providing maximum energy of autoadhesion interaction in the moulding material due to increase of specific surface with small changes of geometric size of particles in comparison with mechanical methods of milling.

  17. Finishes for Wood Decks

    Science.gov (United States)

    Mark Knaebe

    2013-01-01

    Wood decks have become an important part of residential construction. Wood decks can add versatile living space to a home and, with minimal maintenance, provide decades of use. However, wood decks are exposed to high levels of stress from severe weather conditions that shrink and swell the wood. Without proper maintenance, wood decks can develop problems such as checks...

  18. Design and fabrication of spectrally selective emitter for thermophotovoltaic system by using nano-imprint lithography

    Science.gov (United States)

    Kim, Jong-Moo; Park, Keum-Hwan; Kim, Da-Som; Hwang, Bo-yeon; Kim, Sun-Kyung; Chae, Hee-Man; Ju, Byeong-Kwon; Kim, Young-Seok

    2018-01-01

    Thermophotovoltaic (TPV) systems have attracted attention as promising power generation systems that can directly convert the radiant energy produced by the combustion of fuel into electrical energy. However, there is a fundamental limit of their conversion efficiency due to the broadband distribution of the radiant spectrum. To overcome this problem, several spectrally selective thermal emitter technologies have been investigated, including the fabrication of photonic crystal (PhC) structures. In this paper, we present some design rules based on finite-a difference time-domain (FDTD) simulation results for tungsten (W) PhC emitter. The W 2D PhC was fabricated by a simple nano-imprint lithography (NIL) process, and inductive coupled plasma reactive ion etching (ICP-RIE) with an isotropic etching process, the benefits and parameters of which are presented. The fabricated W PhC emitter showed spectrally selective emission near the infrared wavelength range, and the optical properties varied depending on the size of the nano-patterns. The measured results of the fabricated prototype structure correspond well to the simulated values. Finally, compared with the performance of a flat W emitter, the total thermal emitter efficiency was almost 3.25 times better with the 2D W PhC structure.

  19. Measurements of Conversion Efficiency for a Flat Plate Thermophotovoltaic System Using a Photonic Cavity Test System

    International Nuclear Information System (INIS)

    Brown, E.J.; Ballinger, C.T.; Burger, S.R.; Charache, G.W.; Danielson, L.R.; DePoy, D.M.; Donovan, T.J.; LoCascio, M.

    2000-01-01

    The performance of a 1 cm 2 thermophotovoltaic (TPV) module was recently measured in a photonic cavity test system. A conversion efficiency of 11.7% was measured at a radiator temperature of 1076 C and a module temperature of 29.9 C. This experiment achieved the highest direct measurement of efficiency for an integrated TPV system. Efficiency was calculated from the ratio of the peak (load matched) electrical power output and the heat absorption rate. Measurements of these two parameters were made simultaneously to assure the validity of the measured efficiency value. This test was conducted in a photonic cavity which mimicked a typical flat-plate TPV system. The radiator was a large, flat graphite surface. The module was affixed to the top of a copper pedestal for heat absorption measurements. The heat absorption rate was proportional to the axial temperature gradient in the pedestal under steady-state conditions. The test was run in a vacuum to eliminate conductive and convective heat transfer mechanisms. The photonic cavity provides the optimal test environment for TPV efficiency measurements because it incorporates all important physical phenomena found in an integrated TPV system: high radiator emissivity and blackbody spectral shape, photon recycling, Lambertian distribution of incident radiation and complex geometric effects. Furthermore, the large aspect ratio between radiating surface area and radiator/module spacing produces a view factor approaching unity with minimal photon leakage

  20. Microgap thermophotovoltaic systems with low emission temperature and high electric output

    Science.gov (United States)

    Mirmoosa, M. S.; Omelyanovich, M.; Simovski, C. R.

    2016-11-01

    We theoretically show that a thermophotovoltaic (TPV) system enhanced by a wire metamaterial opens the door to a prospective microgap TPVs which will combine high electric output with relatively low temperatures of the emitter. The suggested system comprises an array of parallel metal nanowires grown on top of a photovoltaic semiconductor and standing free in the vacuum gap between the host dielectric layer and the emitter, so that their ends are sufficiently close to the emitting surface. Due to the resonant near-field coupling between this wire medium and the emitter and due to the optimized layered structure of the whole system, the strongly super-Planckian radiative heat flux of resonant nature is engineered. In the suggested system, heavily doped silicon and indium antimonide are considered as the materials for the emitter and the photovoltaic cell, respectively. Also, the parallel nanowires are made of tungsten. Employing the minority-carrier transport model, it is shown that a power output equal to 26 kW m-2 can be achieved when the temperature of the doped-silicon emitter is only 500 °C.

  1. Fabrication of an Omnidirectional 2D Photonic Crystal Emitter for Thermophotovoltaics

    Science.gov (United States)

    Stelmakh, V.; Chan, W. R.; Ghebrebrhan, M.; Soljacic, M.; Joannopoulos, J. D.; Celanovic, I.

    2016-11-01

    In a thermophotovoltaic (TPV) system, a heat source brings an emitter to incandescence and the spectrally confined thermal radiation is converted to electricity by a low-bandgap photovoltaic (PV) cell. Efficiency is dominated by the emitter's ratio of in-band emissivity (convertible by the PV cell) to out-of-band emissivity (inconvertible). Two-dimensional photonic crystals (PhCs) offer high in-band emissivity and low out-of-band emissivity at normal incidence, but have reduced in-band emissivity off-normal. According to Lambert's law, most thermal radiation occurs off-normal. An omnidirectional PhC capable of high in-band emissivity at all angles would increase total in-band power by 55% at 1200°C. In this work, we present the first experimental demonstration an omnidirectional hafnia-filled 2D tantalum PhC emitter suitable for TPV applications such as combustion, radioisotope, and solar TPV. Dielectric filling improved the hemispherical performance without sacrificing stability or ease of fabrication. The numerical simulations, fabrication processes, and optical and thermal characterizations of the PhC are presented in this paper.

  2. Near-field thermophotovoltaic system design and calculation based on coupled-mode analysis

    Science.gov (United States)

    Wang, Bingnan; Lin, Chungwei; Teo, Koon Hoo

    2017-10-01

    The coupling of resonant modes between two surfaces is important in near-field heat transfer and near-field thermophotovoltaic (TPV) systems. Recently, coupled-mode theory (CMT) has been developed for the analysis and optimal design of TPV systems. We use CMT to analyze the "emitter-vacuum-PV cell" configuration and quantitatively show how the emitter of a nanostructure can drastically improve the near-field TPV device performance. The key feature of the nanostructure is the additional geometry-induced resonant mode, whose energy is lower than the original surface plasmon polariton resonant frequency and much closer to the bandgap of the PV cell. Specifically, we show that, with a simple grating structure, the generated power density of a TPV cell is increased from 13 to 34 W/cm2 when the PV cell is fixed at 300 K and the emitter is at 1000 K. The increase is over 20 times higher when both planar and grating emitters are at a lower temperature of 500 K.

  3. Analysis of a Concentrated Solar Thermophotovoltaic System with Thermal Energy Storage

    Science.gov (United States)

    Seyf, Hamid Reza; Henry, Asegun

    2017-01-01

    We analyzed a high temperature concentrated solar thermophotovoltaic (TPV) system with thermal energy storage (TES), which is enabled by the potential usage of liquid metal as a high temperature heat transfer fluid. The system concept combines the great advantages of TES with the potential for low cost and high performance derived from photovoltaic cells fabricated on reusable substrates, with a high reflectivity back reflector for photon recycling. The TES makes the electricity produced dispatchable, and thus the system studied should be compared to technologies such as concentrated solar power (CSP) with TES (e.g., using a turbine) or PV with electrochemical batteries, instead of direct and intermittent electricity generation from flat plate PV alone. Thus, the addition of TES places the system in a different class than has previously been considered and based on the model results, appears worthy of increased attention. The system level analysis presented identifies important cell level parameters that have the greatest impact on the overall system performance, and as a result can help to set the priorities for future TPV cell development.

  4. Metamaterial-based integrated plasmonic absorber/emitter for solar thermo-photovoltaic systems

    Science.gov (United States)

    Wu, Chihhui; Neuner, Burton, III; John, Jeremy; Milder, Andrew; Zollars, Byron; Savoy, Steve; Shvets, Gennady

    2012-02-01

    We present the concept of a solar thermo-photovoltaic (STPV) collection system based on a large-area, nanoimprint-patterned film of plasmonic structures acting as an integrated solar absorber/narrow-band thermal emitter (SANTE). The SANTE film concept is based on integrating broad-band solar radiation absorption with selective narrow-band thermal IR radiation which can be efficiently coupled to a photovoltaic (PV) cell for power generation. By employing a low reflectivity refractory metal (e.g., tungsten) as a plasmonic material, we demonstrate that the absorption spectrum of the SANTE film can be designed to be broad-band in the visible range and narrow-band in the infrared range. A detailed balance calculation demonstrates that the total STPV system efficiency exceeds the Shockley-Queisser limit for emitter temperatures above Te = 1200 K, and achieves an efficiency as high as 41% for Te = 2300 K. Emitter temperatures in this range are shown to be achievable under modest sun concentrations (less than 1000 suns) due to the thermal insulation provided by the SANTE film. An experimental demonstration of the wide-angle, frequency-selective absorptivity is presented.

  5. Optimization of a near-field thermophotovoltaic system operating at low temperature and large vacuum gap

    Science.gov (United States)

    Lim, Mikyung; Song, Jaeman; Kim, Jihoon; Lee, Seung S.; Lee, Ikjin; Lee, Bong Jae

    2018-05-01

    The present work successfully achieves a strong enhancement in performance of a near-field thermophotovoltaic (TPV) system operating at low temperature and large-vacuum-gap width by introducing a hyperbolic-metamaterial (HMM) emitter, multilayered graphene, and an Au-backside reflector. Design variables for the HMM emitter and the multilayered-graphene-covered TPV cell are optimized for maximizing the power output of the near-field TPV system with the genetic algorithm. The near-field TPV system with the optimized configuration results in 24.2 times of enhancement in power output compared with that of the system with a bulk emitter and a bare TPV cell. Through the analysis of the radiative heat transfer together with surface-plasmon-polariton (SPP) dispersion curves, it is found that coupling of SPPs generated from both the HMM emitter and the multilayered-graphene-covered TPV cell plays a key role in a substantial increase in the heat transfer even at a 200-nm vacuum gap. Further, the backside reflector at the bottom of the TPV cell significantly increases not only the conversion efficiency, but also the power output by generating additional polariton modes which can be readily coupled with the existing SPPs of the HMM emitter and the multilayered-graphene-covered TPV cell.

  6. Unidirectional radiative heat transfer with a spectrally selective planar absorber/emitter for high-efficiency solar thermophotovoltaic systems

    Science.gov (United States)

    Kohiyama, Asaka; Shimizu, Makoto; Yugami, Hiroo

    2016-11-01

    A high-efficiency solar thermophotovoltaic (STPV) system has been demonstrated using spectrally selective planar absorber/emitter systems and a GaSb TPV cell. In this study, a novel approach for designing the STPV system based on the efficiency of unidirectional radiative heat transfer has been introduced. To achieve high extraction and photovoltaic conversion efficiencies, the spectrally selective absorber/emitter based on a coherent perfect absorber composed of a thin molybdenum layer sandwiched between hafnium layers was applied. The extraction efficiency was further investigated with respect to the absorber/emitter area ratio. The experimental efficiency of STPV reached 5.1% with the area ratio of 2.3.

  7. Radiative heat transfer enhancement using geometric and spectral control for achieving high-efficiency solar-thermophotovoltaic systems

    Science.gov (United States)

    Kohiyama, Asaka; Shimizu, Makoto; Yugami, Hiroo

    2018-04-01

    We numerically investigate radiative heat transfer enhancement using spectral and geometric control of the absorber/emitter. A high extraction of the radiative heat transfer from the emitter as well as minimization of the optical losses from the absorber leads to high extraction and solar thermophotovoltaic (STPV) system efficiency. The important points for high-efficiency STPV design are discussed for the low and high area ratio of the absorber/emitter. The obtained general guideline will support the design of various types of STPV systems.

  8. Choosing Wood Burning Appliances

    Science.gov (United States)

    Information to assist consumers in choosing a wood burning appliance, including types of appliances, the differences between certified and non-certified appliances, and alternative wood heating options.

  9. Liquefaction of the Used Creosote-Treated Wood in the Presence of Phenol and Its Application to Phenolic Resin

    Science.gov (United States)

    Nubuo Shiraishi; Chung-Yun Hse

    2000-01-01

    A limited initial study was made to evaluate liquefaction of creosote-treated southern pine wood sawdust with liquefaction of birch wood powder as a control. The objective was to assess the feasibility of using creosote-treated southern pine wood as a raw material for the-formulation-of-phenol-based resin adhesives. The liquefaction was conducted in the presence of...

  10. Limited oxygen index levels of impregnated Scots pine wood

    International Nuclear Information System (INIS)

    Tomak, Eylem Dizman; Cavdar, Ayfer Donmez

    2013-01-01

    Highlights: • Scots pine samples were treated with 4 wood preservatives with various concentrations. • Limited oxygen index level was evaluated both for leached and un-leached samples. • All treatments improved fire retardance of samples despite some chemicals leached out. • Samples treated with fireproof agent showed the best results. • LOI of samples treated with boron powder and silicon oil was not changed by leaching. - Abstract: In this study, effect of various concentrations of boron powder, mixture of boric acid and borax, fireproof agent based on liquid blend of limestone, and silicon oil on limited oxygen index levels (LOI) of S. pine wood was investigated. Wood samples were first vacuum treated with the preservatives, and then were subjected to leaching procedure. Samples treated with fireproof agent showed the best results for improving the fire retardancy of wood, furthermore, samples treated with 25%, 50% and 100% of the solution did not burn. Leaching did not considerably change the LOI of wood samples treated with boron powder and silicon oil; however, LOI levels of samples treated with the mixture of boric acid and borax and fireproof agent were affected by leaching procedure probably arising those preservatives did not chemically bond to main wood components. All treatments improved fire retardancy of samples despite some amount of preservatives leached out from wood

  11. Limited oxygen index levels of impregnated Scots pine wood

    Energy Technology Data Exchange (ETDEWEB)

    Tomak, Eylem Dizman, E-mail: eylemdizman@yahoo.com [Forest Industry Engineering Department, Faculty of Forestry, Bursa Technical University, 16200 Bursa (Turkey); Cavdar, Ayfer Donmez [Interior Architecture Department, Faculty of Architecture, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2013-12-10

    Highlights: • Scots pine samples were treated with 4 wood preservatives with various concentrations. • Limited oxygen index level was evaluated both for leached and un-leached samples. • All treatments improved fire retardance of samples despite some chemicals leached out. • Samples treated with fireproof agent showed the best results. • LOI of samples treated with boron powder and silicon oil was not changed by leaching. - Abstract: In this study, effect of various concentrations of boron powder, mixture of boric acid and borax, fireproof agent based on liquid blend of limestone, and silicon oil on limited oxygen index levels (LOI) of S. pine wood was investigated. Wood samples were first vacuum treated with the preservatives, and then were subjected to leaching procedure. Samples treated with fireproof agent showed the best results for improving the fire retardancy of wood, furthermore, samples treated with 25%, 50% and 100% of the solution did not burn. Leaching did not considerably change the LOI of wood samples treated with boron powder and silicon oil; however, LOI levels of samples treated with the mixture of boric acid and borax and fireproof agent were affected by leaching procedure probably arising those preservatives did not chemically bond to main wood components. All treatments improved fire retardancy of samples despite some amount of preservatives leached out from wood.

  12. Overcoming the black body limit in plasmonic and graphene near-field thermophotovoltaic systems.

    Science.gov (United States)

    Ilic, Ognjen; Jablan, Marinko; Joannopoulos, John D; Celanovic, Ivan; Soljacić, Marin

    2012-05-07

    Near-field thermophotovoltaic (TPV) systems with carefully tailored emitter-PV properties show large promise for a new temperature range (600 – 1200K) solid state energy conversion, where conventional thermoelectric (TE) devices cannot operate due to high temperatures and far-field TPV schemes suffer from low efficiency and power density. We present a detailed theoretical study of several different implementations of thermal emitters using plasmonic materials and graphene. We find that optimal improvements over the black body limit are achieved for low bandgap semiconductors and properly matched plasmonic frequencies. For a pure plasmonic emitter, theoretically predicted generated power density of 14 W/cm2 and efficiency of 36% can be achieved at 600K (hot-side), for 0.17eV bandgap (InSb). Developing insightful approximations, we argue that large plasmonic losses can, contrary to intuition, be helpful in enhancing the overall near-field transfer. We discuss and quantify the properties of an optimal near-field photovoltaic (PV) diode. In addition, we study plasmons in graphene and show that doping can be used to tune the plasmonic dispersion relation to match the PV cell bangap. In case of graphene, theoretically predicted generated power density of 6(120) W/cm2 and efficiency of 35(40)% can be achieved at 600(1200)K, for 0.17eV bandgap. With the ability to operate in intermediate temperature range, as well as high efficiency and power density, near-field TPV systems have the potential to complement conventional TE and TPV solid state heat-to-electricity conversion devices.

  13. Collimated thermal radiation transfer via half Maxwell's fish-eye lens for thermophotovoltaics

    Science.gov (United States)

    Chung, Haejun; Zhou, Zhiguang; Bermel, Peter

    2017-05-01

    Thermophotovoltaics (TPV) convert heat into electricity by capturing thermal radiation with a photovoltaic (PV) cell, ideally at efficiencies of 50% or more. However, excess heating of the PV cell from close proximity to the emitter substantially reduces the system efficiency. In this work, we theoretically develop and numerically demonstrate an approach to fundamentally improving TPV systems that allow for a much greater separation of an emitter and a receiver. Thus, we solve the excess heating dilemma, required for achieving theoretically high efficiencies. It consists of a spherically graded index lens known as Maxwell's Fish-Eye (MFE) structure, capable of collimating hemispherical emission into a much narrower range of angles, close to the normal direction. To fully characterize the power radiation profile of the MFE, we perform finite-difference time-domain simulations for a quarter MFE and then map it onto a Gaussian beam approximation. The modeled beam properties are subsequently used to study a half MFE. In an optimized half MFE design, 90% of all thermal photons reach a receiver at a distance of 100 λ; by comparison, only 15.6% of a blackbody emitter reach a receiver in the same geometry. It is also shown that the emission achieved by a half MFE can lead to a photon recycling rate above 95% for below bandgap photons at an emitter-receiver separation of 100 λ. By applying a half MFE, the absolute TPV efficiency can be improved from 5.74% to 37.15%, which represents a significant step forward in realizing high-efficiency TPV systems.

  14. InGaAs/InP Monolithic Interconnected Modules (MIM) for Thermophotovoltaic Applications

    Science.gov (United States)

    Wilt, David M.; Fatemi, Navid S.; Jenkins, Phillip P.; Weizer, Victor G.; Hoffman, Richard W., Jr.; Scheiman, David A.; Murray, Christopher S.; Riley, David R.

    2004-01-01

    There has been a traditional trade-off in thermophotovoltaic (TPV) energy conversion development between systems efficiency and power density. This trade-off originates from the use of front surface spectral controls such as selective emitters and various types of filters. A monolithic interconnected module (MIM) structure has been developed which allows for both high power densities and high system efficiencies. The MIM device consists of many individual indium gallium arsenide (InGaAs) devices series -connected on a single semi-insulating indium phosphide (InP) substrate. The MIMs are exposed to the entire emitter output, thereby maximizing output power density. An infrared (IR) reflector placed on the rear surface of the substrate returns the unused portion of the emitter output spectrum back to the emitter for recycling, thereby providing for high system efficiencies. Initial MIM development has focused on a 1 sq cm device consisting of eight series interconnected cells. MIM devices, produced from 0,74 eV InGAAs, have demonstrated V(sub infinity) = 3.23 volts, J(sub sc) = 70 mA/sq cm and a fill factor of 66% under flashlamp testing. Infrared (IR) reflectance measurement (less than 2 microns) of these devices indicate a reflectivity of less than 82%. MIM devices produced from 0.55 eV InGaAs have also been den=monstrated. In addition, conventional p/n InGaAs devices with record efficiencies (11.7% AM1) have been demonstrated.

  15. The Status of Thermophotovoltaic Energy Conversion Technology at Lockheed Martin Corporation

    Energy Technology Data Exchange (ETDEWEB)

    EJ Brown; PF Baldasaro; SR Burger; LR Danielson; DM DePoy; JM Dolatowski; PM Fourspring; GJ Nichols; WF Topper; TD Rahmlow

    2004-07-29

    In a thermophotovoltaic (TPV) energy conversion system, a heated surface radiates in the mid-infrared range onto photocells which are sensitive at these energies. Part of the absorbed energy is converted into electric output. Conversion efficiency is maximized by reducing the absorption of non-convertible energy with some form of spectral control. In a TPV system, many technology options exist. Our development efforts have concentrated on flat-plate geometries with greybody radiators, front surface tandem filters and a multi-chip module (MCM) approach that allows selective fabrication processes to match cell performance. Recently, we discontinued development of GaInAsSb quaternary cell semiconductor material in favor of ternary GaInAs material. In our last publication (Ref. 1), the authors reported conversion efficiencies of about 20% (radiator 950 C, cells 22 C) for small modules (1-4 cm{sup 2}) tested in a prototypic cavity test environment. Recently, we have achieved measured conversion efficiencies of about 12.5% in larger ({approx}100 cm{sup 2}) test arrays. The efficiency reduction in the larger arrays was probably due to quality and variation of the cells as well as non-uniform illumination from the hot radiator to the cold plate. Modules in these tests used GaInAsSb cells with 0.52 eV bandgap and front surface filters for spectral control. This paper provides details of the individual system components and the rationale for our technical decisions. It also describes the measurement techniques used to record these efficiencies.

  16. Transparent and 'opaque' conducting electrodes for ultra-thin highly-efficient near-field thermophotovoltaic cells.

    Science.gov (United States)

    Karalis, Aristeidis; Joannopoulos, J D

    2017-10-25

    Transparent conducting electrodes play a fundamental role in far-field PhotoVoltaic systems, but have never been thoroughly investigated for near-field applications. Here we show, in the context of near-field planar ultra-thin ThermoPhotoVoltaic cells using surface-plasmon-polariton thermal emitters, that the resonant nature of the nanophotonic system significantly alters the design criteria for the necessary conducting front electrode. The traditional ratio of optical-to-DC conductivities is alone not an adequate figure of merit, instead the desired impedance matching between the emitter and absorber modes along with their coupling to the free-carrier resonance of the front electrode are key for optimal device design and performance. Moreover, we demonstrate that conducting electrodes 'opaque' to incoming far-field radiation can, in fact, be used in the near field with decent performance by taking advantage of evanescent photon tunneling from the emitter to the absorber. Finally, we identify and compare appropriate tunable-by-doping materials for front electrodes in near-field ThermoPhotoVoltaics, specifically molybdenum-doped indium oxide, dysprosium-doped cadmium oxide, graphene and diffused semiconductors, but also for 'opaque' electrodes, tin-doped indium oxide and silver nano-films. Predicted estimated performances include output power density ~10 W/cm 2 with >45% efficiency at 2100 °K emitter temperature and 60 Ω electrode square resistance, thus increasing the promise for high-performance practical devices.

  17. Performance evaluation and parametric optimum design of a molten carbonate fuel cell-thermophotovoltaic cell hybrid system

    International Nuclear Information System (INIS)

    Yang, Zhimin; Liao, Tianjun; Zhou, Yinghui; Lin, Guoxing; Chen, Jincan

    2016-01-01

    Highlights: • A molten carbonate fuel cell-thermophotovoltaic cell hybrid system is established. • The performance characteristics of the hybrid system are systematically evaluated. • The optimal regions of the power output density and efficiency are determined. • The values of key parameters at the maximum power output density are calculated. • The proposed system is proved to have advantages over other hybrid systems. - Abstract: A new model of the hybrid system composed of a molten carbonate fuel cell (MCFC) and a thermophotovoltaic cell (TPVC) is proposed to recovery the waste heat produced by the MCFC. Expressions for the power output and the efficiency of the hybrid system are analytically derived. The performance characteristics of the hybrid system are evaluated. It is found that when the current density of the MCFC, voltage output of the TPVC, electrode area ratio of the MCFC to the TPVC, and energy gap of the material in the photovoltaic cell are optimally chosen, the maximum power output density of the hybrid system is obviously larger than that of the single MCFC. Moreover, the improved percentages of the maximum power output density of the proposed model relative to that of the single MCFC are calculated for differently operating temperatures of the MCFC and are compared with those of some MCFC-based hybrid systems reported in the literature, and consequently, the advantages of the MCFC-TPVC hybrid system are revealed.

  18. Wood Species Recognition System

    OpenAIRE

    Bremananth R; Nithya B; Saipriya R

    2009-01-01

    The proposed system identifies the species of the wood using the textural features present in its barks. Each species of a wood has its own unique patterns in its bark, which enabled the proposed system to identify it accurately. Automatic wood recognition system has not yet been well established mainly due to lack of research in this area and the difficulty in obtaining the wood database. In our work, a wood recognition system has been designed based on pre-processing te...

  19. Resin-Powder Dispenser

    Science.gov (United States)

    Standfield, Clarence E.

    1994-01-01

    Resin-powder dispenser used at NASA's Langley Research Center for processing of composite-material prepregs. Dispenser evenly distributes powder (resin polymer and other matrix materials in powder form) onto wet uncured prepregs. Provides versatility in distribution of solid resin in prepreg operation. Used wherever there is requirement for even, continuous distribution of small amount of powder.

  20. Near-Field Thermal Radiation for Solar Thermophotovoltaics and High Temperature Thermal Logic and Memory Applications

    Science.gov (United States)

    Elzouka, Mahmoud

    This dissertation investigates Near-Field Thermal Radiation (NFTR) applied to MEMS-based concentrated solar thermophotovoltaics (STPV) energy conversion and thermal memory and logics. NFTR is the exchange of thermal radiation energy at nano/microscale; when separation between the hot and cold objects is less than dominant radiation wavelength (˜1 mum). NFTR is particularly of interest to the above applications due to its high rate of energy transfer, exceeding the blackbody limit by orders of magnitude, and its strong dependence on separation gap size, surface nano/microstructure and material properties. Concentrated STPV system converts solar radiation to electricity using heat as an intermediary through a thermally coupled absorber/emitter, which causes STPV to have one of the highest solar-to-electricity conversion efficiency limits (85.4%). Modeling of a near-field concentrated STPV microsystem is carried out to investigate the use of STPV based solid-state energy conversion as high power density MEMS power generator. Numerical results for In 0.18Ga0.82Sb PV cell illuminated with tungsten emitter showed significant enhancement in energy transfer, resulting in output power densities as high as 60 W/cm2; 30 times higher than the equivalent far-field power density. On thermal computing, this dissertation demonstrates near-field heat transfer enabled high temperature NanoThermoMechanical memory and logics. Unlike electronics, NanoThermoMechanical memory and logic devices use heat instead of electricity to record and process data; hence they can operate in harsh environments where electronics typically fail. NanoThermoMechanical devices achieve memory and thermal rectification functions through the coupling of near-field thermal radiation and thermal expansion in microstructures, resulting in nonlinear heat transfer between two temperature terminals. Numerical modeling of a conceptual NanoThermoMechanical is carried out; results include the dynamic response under

  1. Properties of flat-pressed wood plastic composites containing fire retardants

    Science.gov (United States)

    Nadir Ayrilmis; Jan. T. Benthien; Heiko Thoemen; Robert H. White

    2011-01-01

    This study investigated physical, mechanical, and fire properties of the flat-pressed wood plastic composites (WPCs) incorporated with various fire retardants (FRs) [5 or 15% by weight (wt)] at 50 wt % of the wood flour (WF). The WPC panels were made from dry-blended WF, polypropylene (PP) with maleic anhydride grafted PP (2 wt %), and FR powder formulations using a...

  2. Wood's lamp examination

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood lamp examination To use the sharing features on this page, please enable JavaScript. A Wood lamp examination is a test that uses ultraviolet ( ...

  3. Wood's lamp illumination (image)

    Science.gov (United States)

    A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal ... is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally ...

  4. Wood-plastic combination

    International Nuclear Information System (INIS)

    Schaudy, R.

    1978-02-01

    A review on wood-plastic combinations is given including the production (wood and plastic component, radiation hardening, curing), the obtained properties, present applications and prospects for the future of these materials. (author)

  5. Mechanics of Wood Machining

    CERN Document Server

    Csanády, Etele

    2013-01-01

    Wood is one of the most valuable materials for mankind, and since our earliest days wood materials have been widely used. Today we have modern woodworking machine and tools; however, the raw wood materials available are continuously declining. Therefore we are forced to use this precious material more economically, reducing waste wherever possible. This new textbook on the “Mechanics of Wood Machining” combines the quantitative, mathematical analysis of the mechanisms of wood processing with practical recommendations and solutions. Bringing together materials from many sources, the book contains new theoretical and experimental approaches and offers a clear and systematic overview of the theory of wood cutting, thermal loading in wood-cutting tools, dynamic behaviour of tool and work piece, optimum choice of operational parameters and energy consumption, the wear process of the tools, and the general regularities of wood surface roughness. Diagrams are provided for the quick estimation of various process ...

  6. Non_standard Wood

    DEFF Research Database (Denmark)

    Tamke, Martin

    . Using parametric design tools and computer controlled production facilities Copenhagens Centre for IT and Architecture undertook a practice based research into performance based non-standard element design and mass customization techniques. In close cooperation with wood construction software......, but the integration of traditional wood craft techniques. The extensive use of self adjusting, load bearing wood-wood joints contributed to ease in production and assembly of a performance based architecture....

  7. Iron Stain on Wood

    Science.gov (United States)

    Mark Knaebe

    2013-01-01

    Iron stain, an unsightly blue–black or gray discoloration, can occur on nearly all woods. Oak, redwood, cypress, and cedar are particularly prone to iron stain because these woods contain large amounts of tannin-like extractives. The discoloration is caused by a chemical reaction between extractives in the wood and iron in steel products, such as nails, screws, and...

  8. Wood preservative testing

    Science.gov (United States)

    Rebecca Ibach; Stan T. Lebow

    2012-01-01

    Most wood species used in commercial and residential construction have little natural biological durability and will suffer from biodeterioration when exposed to moisture. Historically, this problem has been overcome by treating wood for outdoor use with toxic wood preservatives. As societal acceptance of chemical use changes, there is continual pressure to develop and...

  9. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Roger M. Rowell

    2010-01-01

    The wood industry can expand into new sustainable markets with the formation of a new class of composites with the marriage of the wood industry and the plastics industry. The wood component, usually a flour or fiber, is combined with a thermoplastic to form an extrudable, injectable or thermoformable composite that can be used in many non-structural applications....

  10. Wood Formation in Trees

    Science.gov (United States)

    Melanie Mauriat; Gregoire Le Provost; Phillippe Rozenberg; Sylvain Delzon; Nathalie Breda; Bruno Clair; Catherine Coutand; Jean-Christoph Domec; Thierry Fourcaud; Jacqueline Grima-Pettenati; Raul Herrera; Jean-Charles Leple; Nicolas Richet; Jean-Francois Trontin; Christophe Plomion

    2014-01-01

    Among the ecosystem services provided by forests, wood provisioning takes a central position. Wood and derived products have played a critical role in the evolution of human kind and demand for raw material is increasing in a foreseeable future. Wood is used for energy production, construction and a wide variety of products for which different properties are required....

  11. Request for wood samples

    NARCIS (Netherlands)

    NN,

    1977-01-01

    In recent years the wood collection at the Rijksherbarium was greatly expanded following a renewed interest in wood anatomy as an aid for solving classification problems. Staff members of the Rijksherbarium added to the collection by taking interesting wood samples with them from their expeditions

  12. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  13. Thermal Fluid Analysis of the Combustor Test Setup for a US Army Research Laboratory (ARL) Liquid-Fueled Thermophotovoltaic Power Source Demonstrator

    Science.gov (United States)

    2015-09-01

    500 °C.1 Figure 1 describes the primary components of a TPV system : a heat source, an emitter, and a photovoltaic converter. The heat source...Research Laboratory (ARL) is combustion-based thermophotovoltaic (TPV) power sources. Combustion can be used to convert fuel to heat a surface to...8 Properties of the user-defined Inconel 6004 ...........................................7 Fig. 9 Specific heat vs. temperature for the user

  14. Appropriate materials and preparation techniques for polycrystalline-thin-film thermophotovoltaic cells

    Science.gov (United States)

    Dhere, Neelkanth G.

    1997-03-01

    Polycrystalline-thin-film thermophotovoltaic (TPV) cells have excellent potential for reducing the cost of TPV generators so as to address the hitherto inaccessible and highly competitive markets such as self-powered gas-fired residential warm air furnaces and energy-efficient electric cars, etc. Recent progress in polycrystalline-thin-film solar cells have made it possible to satisfy the diffusion length and intrinsic junction rectification criteria for TPV cells operating at high fluences. Continuous ranges of direct bandgaps of the ternary and pseudoternary compounds such as Hg1-xCdxTe, Pb1-xCdxTe, Hg1-xZnxTe, and Pb1-xZnxS cover the region of interest of 0.50-0.75 eV for efficient TPV conversion. Other ternary and pseudoternary compounds which show direct bandgaps in most of or all of the 0.50-0.75 eV range are Pb1-xZnxTe, Sn1-xCd2xTe2, Pb1-xCdxSe, Pb1-xZnxSe, and Pb1-xCdxS. Hg1-xCdxTe (with x~0.21) has been studied extensively for infrared detectors. PbTe and Pb1-xSnxTe have also been studied for infrared detectors. Not much work has been carried out on Hg1-xZnxTe thin films. Hg1-xCdxTe and Pb1-xCdxTe alloys cover a wide range of cut-off wavelengths from the far infrared to the near visible. Acceptors and donors are introduced in these materials by excess non-metal (Te) and excess metal (Hg and Pb) respectively. Extrinsic acceptor impurities are Cu, Au, and As while and In and Al are donor impurities. Hg1-xCdxTe thin films have been deposited by isothermal vapor-phase epitaxy (VPE), liquid phase epitaxy (LPE), hot-wall metalorganic chemical vapor deposition (MOCVD), electrodeposition, sputtering, molecular beam epitaxy (MBE), laser-assisted evaporation, and vacuum evaporation with or without hot-wall enclosure. The challenge in the preparation of Hg1-xCdxTe is to provide excess mercury incidence rate, to optimize the deposition parameters for enhanced mercury incorporation, and to achieve the requisite stoichiometry, grain size, and doping. MBE and MOCVD

  15. Economics of wood dust

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, J.A.

    1980-11-01

    This article reviews the economic effects of wood dust. The most important use of wood today is a fuel, and wood chips and shavings are sources of feedstock for boilers. Other uses include wood chips in the manufacture of particleboard, wood dust as bedding in riding stables and race tracks, as mulch for florists, and as an absorbent in the meat packing industry. The installation of dust collection systems is strongly urged as the consequences of inadequate collection include rapid machine wear, poor environmental conditions for workers, general interference with work, and its combustibility makes it a constant fire hazard.

  16. Floodplains and wood

    Science.gov (United States)

    Wohl, Ellen

    2013-08-01

    Interactions between floodplains and wood date to the Carboniferous, when stable, multithread channel deposits appear with the evolution of tree-like plants. Foundational geologic texts, such as Lyell's, 1830Principles of Geology, describe floodplain-wood interactions, yet modern technical literature describes floodplain-wood interactions in detail for only a very limited range of environments. This likely reflects more than a century of deforestation, flow regulation, and channel engineering, including instream wood removal, which has resulted in severe wood depletion in most of the world's river networks. Instream wood affects floodplain form and process by altering flow resistance, conveyance and channel-floodplain connectivity, and influencing lateral and vertical accretion of floodplains. Instream wood reflects floodplain form and process as the floodplain influences wood recruitment via bank erosion and overbank flow, and wood transport and storage via floodplain effects on stage-discharge relations and flow resistance. Examining turnover times for instream wood at the reach scale in the context of a wood budget, floodplain characteristics influence fluvial transport and dynamics (wood recruitment), valley geometry (wood transport and storage), and hydraulics and river biota (wood decay and breakage). Accumulations of wood that vary from in situ jams and beaver dams in small channels to transport jams and log rafts in very large rivers can create stable, multithread channels and floodplain wetlands. Floodplain-wood interactions are best understood for a subset of small to medium-sized rivers in the temperate zone. We know little about these interactions on very large rivers, or on rivers in the tropical or boreal regions. This review suggests that most, if not all, channels and floodplains within forested catchments in the temperate zone historically had much greater wood loads and consequently much more obvious and important influences from wood than do

  17. Wood frame systems for wood homes

    Directory of Open Access Journals (Sweden)

    Julio Cesar Molina

    2010-12-01

    Full Text Available The use of constructive systems that combine strength, speed, with competitive differential techniques and mainly, compromising with the environment, is becoming more popular in Brazil. The constructive system in wood frame for houses of up to five stories is very interesting, because it is a light system, structured in reforested treated wood which allows the combination of several materials, besides allowing speed in the construction and total control of the expenses already in the project phase for being industrialized. The structural behavior of the wood frame is superior to the structural masonry in strength, thermal and acoustic comfort. However, in Brazil, the wood frame is still little known and used, due to lack of technical knowledge about the system, prejudice associated the bad use of the wood as construction material, or still, in some cases, lack of normalization. The aim of this manuscript consists of presenting the main technical characteristics and advantages of the constructive system in wood frame homes, approaching the main stages of the constructive process through examples, showing the materials used in the construction, in addition the main international normative recommendations of the project. Thus, this manuscript also hopes to contribute to the popularization of the wood frame system in Brazil, since it is a competitive, fast and ecologically correct system. Moreover, nowadays, an enormous effort of the technical, commercial and industrial section has been accomplished for the development of this system in the country.

  18. Wood production, wood technology, and biotechnological impacts.

    OpenAIRE

    2007-01-01

    In the year 2001, Prof. Dr. Ursula Kües was appointed at the Faculty of Forest Sciences and Forest Ecology of the Georg-August-University Göttingen to the chair Molecular Wood Biotechnology endowed by the Deutsche Bundesstiftung Umwelt (DBU). Her group studies higher fungi in basic and applied research. Research foci are on mushroom development and on fungal enzymes degrading wood and their applications in wood biotechnology. This book has been edited to thank the DBU for all support given to...

  19. Spherical rhenium metal powder

    International Nuclear Information System (INIS)

    Leonhardt, T.; Moore, N.; Hamister, M.

    2001-01-01

    The development of a high-density, spherical rhenium powder (SReP) possessing excellent flow characteristics has enabled the use of advanced processing techniques for the manufacture of rhenium components. The techniques that were investigated were vacuum plasma spraying (VPS), direct-hot isostatic pressing (D-HIP), and various other traditional powder metallurgy processing methods of forming rhenium powder into near-net shaped components. The principal disadvantages of standard rhenium metal powder (RMP) for advanced consolidation applications include: poor flow characteristics; high oxygen content; and low and varying packing densities. SReP will lower costs, reduce processing times, and improve yields when manufacturing powder metallurgy rhenium components. The results of the powder characterization of spherical rhenium powder and the consolidation of the SReP are further discussed. (author)

  20. Urban Wood Waste Resource Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wiltsee, G.

    1998-11-20

    This study collected and analyzed data on urban wood waste resources in 30 randomly selected metropolitan areas in the United States. Three major categories wood wastes disposed with, or recovered from, the municipal solid waste stream; industrial wood wastes such as wood scraps and sawdust from pallet recycling, woodworking shops, and lumberyards; and wood in construction/demolition and land clearing debris.

  1. Granulation of fine powder

    Science.gov (United States)

    Chen, Ching-Fong

    2016-08-09

    A mixture of fine powder including thorium oxide was converted to granulated powder by forming a first-green-body and heat treating the first-green-body at a high temperature to strengthen the first-green-body followed by granulation by crushing or milling the heat-treated first-green-body. The granulated powder was achieved by screening through a combination of sieves to achieve the desired granule size distribution. The granulated powder relies on the thermal bonding to maintain its shape and structure. The granulated powder contains no organic binder and can be stored in a radioactive or other extreme environment. The granulated powder was pressed and sintered to form a dense compact with a higher density and more uniform pore size distribution.

  2. Chapter 9: Wood Energy

    Science.gov (United States)

    Francisco X. Aguilar; Karen Abt; Branko Glavonjic; Eugene Lopatin; Warren  Mabee

    2016-01-01

    The availabilty of information on wood energy continues to improve, particularly for commoditized woodfuels.  Wood energy consumption and production vary in the UNECE region because demand is strngly affected by weather and the prices of competing energy sources.  There has been an increase in wood energy in the power-and-heat sector in the EU28 and North American...

  3. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  4. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust parame...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  5. Operation whey powder

    International Nuclear Information System (INIS)

    Brunner, E.

    1987-01-01

    The odyssey of the contaminated whey powder finally has come to an end, and the 5000 tonnes of whey now are designated for decontamination by means of an ion exchange technique. The article throws light upon the political and economic reasons that sent the whey powder off on a chaotic journey. It is worth mentioning in this context that the natural radioactivity of inorganic fertilizers is much higher than that of the whey powder in question. (HP) [de

  6. Wood pellet seminar

    International Nuclear Information System (INIS)

    Aarniala, M.; Puhakka, A.

    2001-01-01

    The objective of the wood pellet seminar, arranged by OPET Finland and North Karelia Polytechnic, was to deliver information on wood pellets, pellet burners and boilers, heating systems and building, as well as on the activities of wood energy advisors. The first day of the seminar consisted of presentations of equipment and products, and of advisory desks for builders. The second day of the seminar consisted of presentations held by wood pellet experts. Pellet markets, the economy and production, the development of the pellet markets and their problems (in Austria), the economy of heating of real estates by different fuel alternatives, the production, delivery and marketing of wood pellets, the utilization of wood pellet in different utilization sites, the use of wood pellets in detached houses, pellet burners and fireplaces, and conversion of communal real estate houses to use wood pellets were discussed in the presentations. The presentations held in the third day discussed the utilization of wood pellets in power plants, the regional promotion of the production and the use of pellets. The seminar consisted also of visits to pellet manufacturing plant and two pellet burning heating plants

  7. Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Astrup, Thomas; Hansen, Kurt Kielsgaard; Hoffmeyer, Preben

    2005-01-01

    Modelling of moisture transport in wood is of great importance as most mechanical and physical properties of wood depend on moisture content. Moisture transport in porous materials is often described by Ficks second law, but several observations indicate that this does not apply very well to wood....... Recently at the Technical University of Denmark, Department of Civil Engineering, a new model for moisture transport in wood has been developed. The model divides the transport into two phases, namely water vapour in the cell lumens and bound water in the cell walls....

  8. Neutron powder diffraction

    International Nuclear Information System (INIS)

    David, W.I.F.

    1990-01-01

    Neutron powder diffraction is a powerful technique that provides a detailed description of moderately complex crystal structures. This is nowhere more apparent than in the area of high temperature superconductors where neutron powder diffraction has provided precise structural and magnetic information, not only under ambient conditions but also at high and low temperatures and high pressures. Outside superconductor research, the variety of materials studied by neutron powder diffraction is equally impressive including zeolites, fast ionic conductors, permanent magnets and materials undergoing phase transitions. Recent advances that include high resolution studies and real-time crystallography are presented. Future possibilities of neutron powder diffraction are discussed

  9. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    ... through the compaction formulation process and application. Compaction of powder constituents both active ingredient and excipients is examined to ensure consistent and reproducible disintegration and dispersion profiles...

  10. The wood, renewable energy

    International Nuclear Information System (INIS)

    Acket, C.

    2006-12-01

    This document evaluates the french forest situation and its future. Indeed, the wood energy constitutes in France the first renewable energy after the hydraulic. It presents the today situation of the french forest providing statistical data, evaluation of the energy estimation, the carbon fixation, the resources, the perspectives wood energy for 2050, the biofuels and an economic analysis. (A.L.B.)

  11. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Rodney E. Jacobson; Roger M. Rowell

    2005-01-01

    The term “wood-plastic composites” refers to any number of composites that contain wood (of any form) and either thermoset or thermoplastic polymers. Thermosets or thermoset polymers are plastics that, once cured, cannot be remelted by heating. These include cured resins, such as epoxies and phenolics, plastics with which the forest products industry is most familiar (...

  12. Wood supply and demand

    Science.gov (United States)

    Peter J. Ince; David B. McKeever

    2011-01-01

    At times in history, there have been concerns that demand for wood (timber) would be greater than the ability to supply it, but that concern has recently dissipated. The wood supply and demand situation has changed because of market transitions, economic downturns, and continued forest growth. This article provides a concise overview of this change as it relates to the...

  13. Heat sterilization of wood

    Science.gov (United States)

    Xiping Wang

    2010-01-01

    Two important questions should be considered in heat sterilizing solid wood materials: First, what temperature–time regime is required to kill a particular pest? Second, how much time is required to heat the center of any wood configuration to the kill temperature? The entomology research on the first question has facilitated the development of international standards...

  14. Multifactorial antimicrobial wood protectants

    Science.gov (United States)

    Robert D. Coleman; Carol A. Clausen

    2008-01-01

    It is unlikely that a single antimicrobial compound, whether synthetic or natural, will provide the ‘magic bullet’ for eliminating multiple biological agents affecting wood products. Development of synergistic combinations of selected compounds, especially those derived from natural sources, is recognized as a promising approach to improved wood protection. Recent...

  15. Material model for wood

    NARCIS (Netherlands)

    Sandhaas, C.; Van de Kuilen, J.W.G.

    2013-01-01

    Wood is highly anisotropic and shows ductile behaviour in compression and brittle behaviour in tension and shear where both failure modes can occur simultaneously. A 3D material model for wood based on the concepts of continuum damage mechanics was developed. A material subroutine containing the

  16. Economy of wood supply

    International Nuclear Information System (INIS)

    Imponen, V.

    1993-01-01

    Research and development of wood fuels production was vigorous in the beginning of the 1980's. Techniques and working methods used in combined harvesting and transportation of energy and merchantable wood were developed in addition to separate energy wood delivery. After a ten year silent period the research on this field was started again. At present the underutilization of forest supplies and the environmental effects of energy production based on fossil fuels caused the rebeginning of the research. One alternative for reduction of the price of wood fuels at the utilization site is the integration of energy and merchantable wood deliveries together. Hence the harvesting and transportation devices can be operated effectively, and the organizational costs are decreased as well. The wood delivery costs consist of the stumpage price, the harvesting and transportation costs, and of general expenses. The stumpage price form the largest cost category (over 50 %) of the industrial merchantable wood delivery, and the harvesting and transportation costs in the case of thinningwood delivery. Forest transportation is the largest part of the delivery costs of logging residues. The general expenses, consisting of the management costs and the interest costs of the capital bound to the storages, form a remarkable cost category in delivery of low-rank wood for energy or conversion purposes. The costs caused by the harvesting of thinningwood, the logging residues, chipping and crushing, the lorry transportation are reviewed in this presentation

  17. Measurement of loose powder density

    International Nuclear Information System (INIS)

    Akhtar, S.; Ali, A.; Haider, A.; Farooque, M.

    2011-01-01

    Powder metallurgy is a conventional technique for making engineering articles from powders. Main objective is to produce final products with the highest possible uniform density, which depends on the initial loose powder characteristics. Producing, handling, characterizing and compacting materials in loose powder form are part of the manufacturing processes. Density of loose metallic or ceramic powder is an important parameter for die design. Loose powder density is required for calculating the exact mass of powder to fill the die cavity for producing intended green density of the powder compact. To fulfill this requirement of powder metallurgical processing, a loose powder density meter as per ASTM standards is designed and fabricated for measurement of density. The density of free flowing metallic powders can be determined using Hall flow meter funnel and density cup of 25 cm/sup 3/ volume. Density of metal powders like cobalt, manganese, spherical bronze and pure iron is measured and results are obtained with 99.9% accuracy. (author)

  18. Wood adhesives : vital for producing most wood products

    Science.gov (United States)

    Charles R. Frihart

    2011-01-01

    A main route for the efficient utilization of wood resources is to reduce wood to small pieces and then bond them together (Frihart and Hunt 2010). Although humankind has been bonding wood since early Egyptian civilizations, the quality and quantity of bonded wood products has increased dramatically over the past 100 years with the development of new adhesives and...

  19. Mechanical performance of wood plastic composites containing decayed wood

    OpenAIRE

    Ayrılmış, Nadir; Kaymakcı, Alperen; Güleç, Türker

    2014-01-01

    This study investigated the potential use of the decayed wood in the manufacture of wood plastic composite (WPC) panel. Scots pine (Pinus sylvestris) sound wood and decayed wood (brown-rot fungi) were used as wood material. Three levels of 30%, 40%, and 50% of sound wood and decayed wood, based on the composition by weight, were mixed with the polypropylene with 3% (based on weight) maleic anhydride grafted PP (MAPP) as a coupling agent. The compound pellets were prepared from twin screw co-r...

  20. Cord Wood Testing in a Non-Catalytic Wood Stove

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trojanowski, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wei, G. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-06-30

    EPA Method 28 and the current wood stove regulations have been in-place since 1988. Recently, EPA proposed an update to the existing NSPS for wood stove regulations which includes a plan to transition from the current crib wood fuel to cord wood fuel for certification testing. Cord wood is seen as generally more representative of field conditions while the crib wood is seen as more repeatable. In any change of certification test fuel, there are questions about the impact on measured results and the correlation between tests with the two different fuels. The purpose of the work reported here is to provide data on the performance of a noncatalytic stove with cord wood. The stove selected has previously been certified with crib wood which provides a basis for comparison with cord wood. Overall, particulate emissions were found to be considerably higher with cord wood.

  1. Chapter 6: Wood energy and competing wood product markers

    Science.gov (United States)

    Kenneth E. Skog; Robert C. Abt; Karen Abt

    2014-01-01

    Understanding the effect of expanding wood energy markets is important to all wood-dependent industries and to policymakers debating the implementation of public programs to support the expansion of wood energy generation. A key factor in determining the feasibility of wood energy projects (e.g. wood boiler or pellet plant) is the long-term (i.e. 20-30year) supply...

  2. Wood wastes: Uses

    International Nuclear Information System (INIS)

    Cipro, A.

    1993-01-01

    The 1,500 industrial firms manufacturing furniture in the Italian Province of Treviso can generate up to 190,000 tonnes of wood wastes annually. In line with the energy conservation-environmental protection measures contained in Italian Law No. 475/88, this paper indicates convenient uses for these wood wastes - as a raw material for fibreboards or as a fuel to be used in the furniture manufacturing plants themselves and in kilns producing lime. Reference is made to the wood wastes gasification/power generation system being developed by ENEA (the Italian Agency for New Technology, Energy and the Environment)

  3. Fatigue Damage in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1996-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Fatigue failure is found to depend both on the total time under load and on the number of cycles.Recent accelerated fatigue research on wood is reviewed, and a discrepancy between...... to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation between stiffness reduction...

  4. OIL SOLUTIONS POWDER

    Science.gov (United States)

    Technical product bulletin: aka OIL SOLUTIONS POWDER, SPILL GREEN LS, this miscellaneous oil spill control agent used in cleanups initially behaves like a synthetic sorbent, then as a solidifier as the molecular microencapsulating process occurs.

  5. Magnetically responsive enzyme powders

    Science.gov (United States)

    Pospiskova, Kristyna; Safarik, Ivo

    2015-04-01

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (-20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties.

  6. Non_standard Wood

    DEFF Research Database (Denmark)

    Tamke, Martin

    . Using parametric design tools and computer controlled production facilities Copenhagens Centre for IT and Architecture undertook a practice based research into performance based non-standard element design and mass customization techniques. In close cooperation with wood construction software......Non-Standard elements in architecture bear the promise of a better more specific performance (Oosterhuis 2003). A new understanding of design evolves, which is focusing on open ended approaches, able to negotiate between shifting requirements and to integrate knowledge on process and material......, but the integration of traditional wood craft techniques. The extensive use of self adjusting, load bearing wood-wood joints contributed to ease in production and assembly of a performance based architecture....

  7. Power and hydrogen production from ammonia in a micro-thermophotovoltaic device integrated with a micro-reformer

    International Nuclear Information System (INIS)

    Um, Dong Hyun; Kim, Tae Young; Kwon, Oh Chae

    2014-01-01

    Power and hydrogen (H 2 ) production by burning and reforming ammonia (NH 3 ) in a micro-TPV (microscale-thermophotovoltaic) device integrated with a micro-reformer is studied experimentally. A heat-recirculating micro-emitter with the cyclone and helical adapters that enhance the residence time of fed fuel-air mixtures and uniform burning burns H 2 -added NH 3 -air mixtures. A micro-reformer that converts NH 3 to H 2 using ruthenium as a catalyst surrounds the micro-emitter as a heat source. The micro-reformer is surrounded by a chamber, the inner and outer walls of which have installations of gallium antimonide photovoltaic cells and cooling fins. For the micro-reformer-integrated micro-TPV device the maximum overall efficiency of 8.1% with electrical power of 4.5 W and the maximum NH 3 conversion rate of 96.0% with the H 2 production rate of 22.6 W (based on lower heating value) are obtained, indicating that the overall efficiency is remarkably enhanced compared with 2.0% when the micro-TPV device operates alone. This supports the potential of improving the overall efficiency of a micro-TPV device through integrating it with a micro-reformer. Also, the feasibility of using NH 3 as a carbon-free fuel for both burning and reforming in practical micro power and H 2 generation devices has been demonstrated. - Highlights: • Performance of micro-TPV device integrated with micro-reformer is evaluated. • Feasibility of using NH 3 –H 2 blends in integrated system has been demonstrated. • Integration with micro-reformer improves performance of micro-TPV device. • Maximum overall efficiency of 8.1% is found compared with 2.0% without integration

  8. Magnetically responsive enzyme powders

    International Nuclear Information System (INIS)

    Pospiskova, Kristyna; Safarik, Ivo

    2015-01-01

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction

  9. Characteristics of Inconel Powders for Powder-Bed Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Quy Bau Nguyen

    2017-10-01

    Full Text Available In this study, the flow characteristics and behaviors of virgin and recycled Inconel powder for powder-bed additive manufacturing (AM were studied using different powder characterization techniques. The results revealed that the particle size distribution (PSD for the selective laser melting (SLM process is typically in the range from 15 μm to 63 μm. The flow rate of virgin Inconel powder is around 28 s·(50 g−1. In addition, the packing density was found to be 60%. The rheological test results indicate that the virgin powder has reasonably good flowability compared with the recycled powder. The inter-relation between the powder characteristics is discussed herein. A propeller was successfully printed using the powder. The results suggest that Inconel powder is suitable for AM and can be a good reference for researchers who attempt to produce AM powders.

  10. Nanocarbon materials obtained of coniferous trees in the composition of black powder

    Directory of Open Access Journals (Sweden)

    Zulkhair Mansurov

    2012-03-01

    Full Text Available Obtained black powders from coniferous wood. The carbon content of up to 90% can be used in warfare, pyrotechnics and industries. In the Republic of Kazakhstan does not produce gunpowder. In the energy-intensive materials laboratory, developed industrial black powders (ordinary, composed of components produced in the republic of Kazakhstan. Sulfur, activated carbon, based on apricot seeds and rice husks, softwood sawdust, which have lower costs than their foreign counterparts.

  11. Wood pellet research program

    International Nuclear Information System (INIS)

    Sohkansanj, S.; Bi, T.

    2006-01-01

    Wood pellets are composed of waste wood materials such as sawmill residue, municipal landfill waste and grain crops. Due to the high temperature combustion used to form the waste materials into the pellet, no additives or glues are necessary to bind them. The pellets are typically used for home heating; heat and power production; poultry bedding; and in biorefineries. This presentation provided an outline of the University of British Columbia wood pellet research and development program. Research at the university is being conducted to develop new types of pellets. Researchers at the program also analyze the physical and chemical properties of pellets in order to optimize pellet density and heating values. Wood pellet modelling and simulation studies are carried out, and various training and education programs are also offered. Research is currently being conducted to develop a reactor for off-gassing experiments. This presentation also provided details of a study investigating the economics of wood pellet production and transport. Pellet production costs and feedstock costs were compared. A summary of the costs and energy inputs of pellet production included details of product storage; transportation and transfer; handling; and transportation to energy plants. It was concluded that more than 35 per cent of the energy content of biomass is used up in the processing and transport of Canadian wood pellets to Europe. refs., tabs., figs

  12. Biaxially textured articles formed by powder metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-07-29

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

  13. Surface modification of pharmaceutical powders

    OpenAIRE

    Zhou, Qi

    2017-01-01

    This thesis describes a body of work to investigate a mechanical dry powder coating approach aiming to modify the surface properties of fine pharmaceutical powders. Powders were coated with magnesium stearate (MgSt) in order to improve their bulk powder properties such as flowability, fluidization and aerosolization. The flow characteristics of a cohesive milled lactose monohydrate powder (Pharmatose® 450M, VMD around 20 μm) were substantially improved by processing with 1% w/w magn...

  14. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  15. Wood fuel and the environment

    International Nuclear Information System (INIS)

    Foster, C.A.

    1992-01-01

    The purpose of this paper is to try and demonstrate the role that the use of Wood as a Fuel can play in our environment. The term ''Wood Fuel'', for the purposes of these proceedings, refers to the use of wood obtained from the forest or the farm. It does not refer to waste wood from for example buildings. The role of wood fuel in the environment can be assessed at many different levels. In this paper three different scales of ''Environment'' and the role of wood fuel in each, will be considered. These three scales are namely the global environment, the local environment, and the National (community) environment. (Author)

  16. SiC/C composites prepared from wood-based carbons by pulse current sintering with SiO2 : Electrical and thermal properties

    NARCIS (Netherlands)

    Fujisawa, M; Hata, T; Bronsveld, P; Castro, [No Value; Tanaka, F; Kikuchi, H; Furuno, T; Imamura, Y

    2004-01-01

    A powder mix of wood charcoal and SiO2 was sintered into a SiC/C composite. The heat treatment temperatures were 1400-1800 degreesC, the SiO2 concentration 0, 10, 30 and 50 wt.% with respect to the dry weight of wood charcoal. The microstructure, electrical resistance and thermal conductivity were

  17. Energy from wood - an overview

    International Nuclear Information System (INIS)

    Nussbaumer, T.

    2000-01-01

    The present publication is the introduction to a series of papers on fundamentals and applications of wood energy. It summarizes figures and data of the actual situation of fuel wood utilization in Switzerland and its potential for the future. Further, the advantages of bio-energy are discussed and the possibilities of funding for bio-energy in Switzerland are described. Wood contributes with 2.5% to the total energy demand in Switzerland nowadays. However, the utilization of wood energy can be more than doubled, which is one of the targets of the Swiss energy policy. The supply chains for the different types of fuel wood are described and specifications and prices of log wood, forestry wood chips and wood residues are presented. The main applications of wood energy are residential heating with manually operated wood boilers and stoves, on the one hand, and heat production with automatic wood furnaces in industry and communities, on the other hand. Automatic furnaces have been promoted in the past ten years and hence they contribute nowadays with more than 50% to the energy supply from wood with a further growing share. As an assistance for further information, a list of institutions and addresses in the field of wood energy in Switzerland is given in the paper. (author)

  18. Turning wood residues into wood revenues

    International Nuclear Information System (INIS)

    Graham, R.G.; Kravetz, Don

    1996-01-01

    Ensyn is a profitable commercial company which derives its revenues from the conversion of wood residues into liquid biofuel and chemicals. The technology, Rapid Thermal Processing (RTP (TM) )is based on extremely fast ''cracking'' of biomass which results in light liquid yields exceeding 70% by weight, from wood. Whether producing chemicals or liquid biofuel, the RTP plant is configured identically and operated essentially in the same mode. Chemicals production simply allows economical production to occur at a lower plant capacity, as low as 2 tonnes/day, than is feasible for a dedicated fuel plant (typically greater than 100 tonnes/day). Ensyn has developed the commercialisation of RTP TM from bench to industrial scale in 10 years. A variety of crative funding initiatives in the early years allowed for capital to be raised for R and D without the loss of intellectual property (IP). The transition years of technology demonstration, prior to full commercialisation, were funded by a blend of revenues from venture capital and public sources, and by quickly tapping into a niche market for RTP TM . The utilisation of the technology at the niche market scale opened the doors to the larger fuel and commodity markets. Once, again, both IP and control of the company were maintained during these years. Flexibility, creativity and expertise are necessary to understand the significance of various financing options (private investments, commercial banking and bond issues) and to integrate these options with various renewable energy, recycling and tax incentives. Understanding these options with various renewable energy, recycling and tax incentives is necessary. Understanding both the core and peripheral needs of the customer are essential in successfully advancing a commercial wood energy venture. Ensyn's experience in these areas is the focus of the paper. (Author)

  19. Precision wood particle feedstocks

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-07-30

    Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

  20. Methane from wood

    International Nuclear Information System (INIS)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S.

    2005-07-01

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  1. Wood-pastures of Europe

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Hartel, Tibor; Martín-López, Berta

    2015-01-01

    Wood-pastures are archetypes of High Nature Value Farmlands in Europe and hold exceptional ecological, social, and cultural values. Yet, wood-pastures have been through a sharp decline all over Europe, mainly due to processes of agricultural intensification and abandonment. Recently, wood......-pastures have found increasing attention from conservation science and policy across Europe. In this paper we (i) perform the first pan-European assessment of wood-pastures, considering individual countries and biogeographic regions, (ii) present the ecological and social-cultural values of a wide diversity...... of wood-pasture systems in Europe, (iii) outline management challenges around wood-pastures, and (iv) provide insights for the policy agenda targeting wood-pastures in Europe. We estimate that wood-pastures cover an area of approximately 203,000km2 in the European Union (EU...

  2. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  3. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation...

  4. TCP HolyWood

    OpenAIRE

    Oscar Núñez Mori

    2005-01-01

    We introduce a new end-to-end, sender side Transport Control Protocol called TCP HolyWood or in short TCP-HW. In a simulated wired environment, TCP HolyWood outperforms in average throughput, three of the more important TCP protocols ever made, we are talking about TCP Reno, TCP Westwood, and TCP Vegas; and in average jitter to TCP Reno and TCP Vegas too. In addition, according to Jain’s index, our proposal is as fair as TCP Reno, the Standard. Apresentamos um novo Protocolo de Controle de...

  5. The Asian Wood Pellet Markets

    Science.gov (United States)

    Joseph A. Roos; Allen Brackley

    2012-01-01

    This study examines the three major wood pellet markets in Asia: China, Japan, and South Korea. In contrast to the United States, where most wood pellets are used for residential heating with pellet stoves, a majority of the wood pellets in Asia are used for co-firing at coal-fired power plants. Our analysis indicated that Japan is the largest importer of wood pellets...

  6. Magnetically responsive enzyme powders

    Czech Academy of Sciences Publication Activity Database

    Pospišková, K.; Šafařík, Ivo

    2015-01-01

    Roč. 380, APR 2015 (2015), s. 197-200 ISSN 0304-8853 R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : enzyme powders * cross-linking * magnetic modification * magnetic separation * magnetic iron oxides particles * microwave-assisted synthesis Subject RIV: CE - Biochemistry Impact factor: 2.357, year: 2015

  7. Laser cladding with powder

    NARCIS (Netherlands)

    Schneider, M.F.; Schneider, Marcel Fredrik

    1998-01-01

    This thesis is directed to laser cladding with powder and a CO2 laser as heat source. The laser beam intensity profile turned out to be an important pa6 Summary rameter in laser cladding. A numerical model was developed that allows the prediction of the surface temperature distribution that is

  8. Classroom Demonstrations of Wood Properties.

    Science.gov (United States)

    Foulger, A. N.

    Presented in this manual are 20 activities selected to show some of the properties of wood and how these properties relate to the cellular structure of wood. Each activity includes stated objectives, indicates materials needed, and explains procedures. Illustrations related to the activities, glossary of terms, and photographs of wood structure…

  9. Status of wood energy applications

    International Nuclear Information System (INIS)

    Zerbe, J.I.

    1991-01-01

    In this address, the potential of wood and wood residues to supply future energy needs is examined. In addition, the possible environmental impact of the use of wood fuels on global climate change is discussed. Technologies for the development of new fuels are described

  10. Wrong way: Heating with wood

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-01

    Energy experts state that 'Heating with wood is a hobby, at the most'. Of course, one can save oil by heating with wood, but cost calculations shaw that it is a highly uneconomical substitute. On the other hand, wood can be recommended for thermal insulation.

  11. Strength loss in decayed wood

    Science.gov (United States)

    Rebecca E. Ibach; Patricia K. Lebow

    2014-01-01

    Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that...

  12. Ovalbumin as a Wood Adhesive

    Science.gov (United States)

    Charles R. Frihart; Holly Satori; Zhu Rongxian; Michael J. Birkeland

    2014-01-01

    Use of proteins to bond wood dominated industrial production until the middle of the 20th century (1). The ensuing creation of the plywood and glulam beam industries allowed for more efficient use of wood resources than is possible with solid wood products. Many protein sources have been used as adhesives, including plant (soybean) and animal (blood, fish scales,...

  13. Wood construction and magnetic characteristics of impregnated type magnetic wood

    International Nuclear Information System (INIS)

    Oka, Hideo; Hojo, Atsushi; Seki, Kyoushiro; Takashiba, Toshio

    2002-01-01

    The results of experiments involving the AC and DC magnetic characteristics of impregnated type magnetic wood were studied by taking into consideration the wood construction and fiber direction. The experimental results show that the sufficient amount of impregnated magnetic fluid varies depending on the fiber direction and length, and the grain face of the wood material. The impregnated type magnetic wood sample that is fully impregnated by magnetic fluid has a 60% saturation magnetization compared to the saturation magnetization of magnetic fluid. Samples for which the wood fiber direction was the same as the direction of the magnetic path had a higher magnetization intensity and permeability

  14. Study of wood polymer combinations from woods of Kashmir

    International Nuclear Information System (INIS)

    Garg, V.P.; Hari Mohan; Rao, K.N.

    1983-01-01

    This report describes the studies conducted to upgrade inferior woods of Kashmir by the application of radiation polymerization process. The process has brought about improvements in the physical and mechanical properties of wood. Wood polymer composite samples have been studied for their use in flooring, wall panelling, roofing shingles, wood carving and in other decorative items. It has been shown that 10% ethyl silicate, when present along with methyl methacrylate or styrene, considerably improves the impact strength and such wood polymer composite samples do not crack even on nailing. Wood polymer composites have been tested for carving and it has been shown that with 50% polymer content, carving quality is preserved. It has also been shown that surface coated wood is more advantageous for use in roofing shingles. (author)

  15. History of wood machining

    Science.gov (United States)

    Peter Koch

    1967-01-01

    The history of wood machining is closely tied to advanced in metallurgy and power sources. It has been strongly and continuously shaped by prevailing economic forces and the rise and decline of other contemporary industries. This paper sketches a few of the highlights, with emphasis on developments in North America.

  16. Grant Wood: "American Gothic."

    Science.gov (United States)

    Fitzgerald, Diane M.

    1988-01-01

    Presents a lesson plan which exposes students in grades 10-12 to the visual symbols and historical references contained in Grant Wood's "American Gothic." Includes background information on the artist and the painting, instructional strategies, a studio activity, and evaluation criteria. (GEA)

  17. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Matos, O.; Ribeiro, R. [Biomass Centre for Energy - CBE, Miranda do Corvo (Portugal)

    1997-12-31

    The energy policy of the EC, as well as most of member states points to a sizeable increase of energy production based on renewable energy sources, wood, wood residues, agricultural residues, energy crops including SRF, organic sludges, solid residues, etc. Most recent goals indicate a desirable duplication of today`s percentage by 2010. The reasons for this interest, besides diversification of sources, less dependence on imported fuels, use of endogenous resources, expected decrease of fossil fuel reserves, use of available land, additional employment and income for rural communities, etc., are related to important environmental benefits namely in terms of emissions of hot house gases. Wood waste, resulting from forest operations, cleaning, cultural and final cuttings, and from wood based industries, constitute a special important resource by reason of quality and availability. In addition to this they do not require additional land use and the removal is beneficial. In the run-up to the becoming December`s 1997 `Climate Change Summit` in Kioto, there is mounting pressure on companies to plan on carbon cuts. (author) 6 refs., 1 tab.

  18. Chapter 3: Wood Decay

    Science.gov (United States)

    Dan Cullen

    2014-01-01

    A significant portion of global carbon is sequestered in forest systems. Specialized fungi have evolved to efficiently deconstruct woody plant cell walls. These important decay processes generate litter, soil bound humic substances, or carbon dioxide and water. This chapter reviews the enzymology and molecular genetics of wood decay fungi, most of which are members of...

  19. Thermal Conversion of Pine Wood Char to Carbon Nanomaterials in the Presence of Iron Nanoparticles

    Science.gov (United States)

    Sung Phil Mun; Zhiyong Cai; Fumiya Watanabe; Umesh P. Agarwal; Jilei. Zhang

    2012-01-01

    Southern yellow pine (Pinus taeda) wood char powder was thermally treated at 1,000:C in the presence of a 25-nm-size Fe nanoparticle catalyst. The thermally treated carbon materials were analyzed by Raman spectroscopy and high-resolution transmission electron microscopy. Well-aligned graphitic carbon structures with 15 to 17 layers on...

  20. Thermoelectric properties of SiC/C composites from wood charcoal by pulse current sintering

    NARCIS (Netherlands)

    Fujisawa, M; Hata, T; Bronsveld, P; Castro, [No Value; Tanaka, F; Kikuchi, H; Imamura, Y

    2005-01-01

    SiC/C composites were investigated by sintering a mix of wood charcoal and SiO2 powder (32-45 mu m) at 1400, 1600 and 1800 degrees C under N-2 atmosphere with a pulse current sintering method. Thermoelectric properties of SiC/C composites were investigated by measuring the Seebeck coefficient and

  1. Synthesis of Uranium nitride powders using metal uranium powders

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kim, Dong Joo; Oh, Jang Soo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik

    2012-01-01

    Uranium nitride (UN) is a potential fuel material for advanced nuclear reactors because of their high fuel density, high thermal conductivity, high melting temperature, and considerable breeding capability in LWRs. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. The carbothermic reduction has an advantage in the production of fine powders. However it has many drawbacks such as an inevitable engagement of impurities, process burden, and difficulties in reusing of expensive N 15 gas. Manufacturing concerns issued in the carbothermic reduction process can be solved by changing the starting materials from oxide powder to metals. However, in nitriding process of metal, it is difficult to obtain fine nitride powders because metal uranium is usually fabricated in the form of bulk ingots. In this study, a simple reaction method was tested to fabricate uranium nitride powders directly from uranium metal powders. We fabricated uranium metal spherical powder and flake using a centrifugal atomization method. The nitride powders were obtained by thermal treating those metal particles under nitrogen containing gas. We investigated the phase and morphology evolutions of powders during the nitriding process. A phase analysis of nitride powders was also a part of the present work

  2. Dispersing powders in liquids

    CERN Document Server

    Nelson, RD

    1988-01-01

    This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

  3. Co-culturing Effects of Coexisting Bacteria on Wood Degradation by Trametes versicolor.

    Science.gov (United States)

    Kamei, Ichiro

    2017-01-01

    White-rot fungi are the main decomposers of wood cell-wall polymer in forest ecosystems. Little is known, however, about the interactions between white-rot fungi and other coexisting microorganisms in decayed wood. A white-rot fungus, Trametes versicolor strain TN6F, was isolated from a fruit body, and 44 strains of coexisting cultivable bacteria were isolated from its substrate, natural white rot-decayed wood. The effects of these bacteria on fungal growth were examined by an in vitro confrontation growth assay. Among the isolates, nine bacterial strains inhibited the growth of strain TN6F, while 35 strains did not affect the growth of TN6F. However, when co-cultured with strain TN6F on wood powder, many bacterial strains promoted the weight loss of the substrate. A subsequent chemical composition analysis showed that co-culturing accelerated delignification. Higher laccase activity was detected when strain TN6F was co-cultured on wood powder medium with bacterial strains TN6W-26 or TN6W-27. These results indicate that some bacterial strains might promote wood degradation.

  4. Radioactivity of Wood and Environment

    International Nuclear Information System (INIS)

    Hus, M.; Kosutic, K.; Lulic, S.

    2003-01-01

    Nuclear experiments in the atmosphere and nuclear accidents caused global deposition of artificial radionuclides in the soil of Earth's northern hemisphere, the territory of the Republic of Croatia included. Soil contamination by radionuclides resulted in their deposition in plants growing on the contaminated soil as well as in the trees. Large area of the Republic of Croatia is covered with wood, which is exploited in manufacture of industrial wood and for firewood. From approximately 3 million cubic metres of wood exploited annually, nearly one third serves for firewood. In the process of burning a smaller portion of radionuclides deposited in the wood evaporates and goes to atmosphere while a larger portion is retained in the ash. In this paper are presented the results of natural radionuclides 4 0K , 2 32T h and 2 38U as well as of artificial radionuclide 1 37C s content determination in the wood, wood briquette, charcoal and in ash remained after burning the wood, wood briquette and charcoal. The obtained results are discussed from wood radiocontamination aspect and from the aspect of potential environmental radiocontamination by the products from wood burning process. (author)

  5. Lignin-Retaining Transparent Wood.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Rojas, Ramiro; Yan, Min; Lawoko, Martin; Berglund, Lars

    2017-09-11

    Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80 wt % of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83 %, haze of 75 %, thermal conductivity of 0.23 W mK -1 , and work-tofracture of 1.2 MJ m -3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  6. Lump wood combustion process

    Science.gov (United States)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  7. Mechanical properties of wood

    Science.gov (United States)

    David W. Green; Jerrold E. Winandy; David E. Kretschmann

    1999-01-01

    The mechanical properties presented in this chapter were obtained from tests of small pieces of wood termed “clear” and “straight grained” because they did not contain characteristics such as knots, cross grain, checks, and splits. These test pieces did have anatomical characteristics such as growth rings that occurred in consistent patterns within each piece. Clear...

  8. Out of the woods.

    Science.gov (United States)

    Jacobson, J L

    1992-01-01

    Throughout Africa, Asia and Latin America women are pushed out of forests and from their maintenance by governments and private interests for cash crop development disregarding the role of women in conserving forests. In developing countries forests are a source of wood for fuel; 60-80% of women gather wood for family needs in America. Fruits, vegetables, and nuts gathered in woods enhance their diet. Indonesian women pick bananas, mangos, guavas, and avocados from trees around their homes; in Senegal shea-nut butter is made from a local tree fruit to be sold for cash. Women provide labor also in logging, wood processing, and tree nurseries. They make charcoal and grow seedlings for sale. In India 40% of forest income and 75% of forest products export earnings are derived from nonwood resources. Poor, rural women make items out of bamboo, rattan, and rope to sell: 48% of women in an Egyptian province make a living through such activities. In India 600,000 women harvest tendu leaves for use as wrappings for cigarettes. The expansion of commercial tree plantations replacing once communal natural forests has forced poor households to spend up to 4-% of their income on fuel that they used to find in forests. Tribal women in India know the medicinal uses of 300 forest species, and women in Sierra Leone could name 31 products they obtained or made from trees and bushes, while men named only 8 items. Only 1 forestry project appraised by the World Bank during 1984-97 named women as beneficiaries, and only 1 out of 33 rural development programs funded by the World Bank did. Women provide food, fuel, and water for their families in subsistence economies, they know sustainable methods of forestry, yet they are not included in development programs whose success or failure could hinge on more attention to women's contribution and on more equity.

  9. Wood fuels utilization in Central Europe - the wood fuels consumption and the targets of utilization

    International Nuclear Information System (INIS)

    Alakangas, E.

    1999-01-01

    Following subjects are discussed in this presentation: The share of bioenergy of the total energy consumption in EU region; the wood fuels consumption in EU region in 1995; the division of bioenergy utilization (households, wood- based district heating, wood consumption in industry, power generation from wood and residues, biofuels, biogas and sludges); wood fuels consumption in households in EU countries in 1995; wood consumption in France; the additional wood fuel consumption potential in France; Blan bois - wood energy program; French wood energy markets; German wood energy markets; energy consumption in Germany; wood consumption in Bavaria; the wood fuels potential in Bavaria; wood fuels consumption in households in Bavaria; wood fuels consumption for district heating in Bavaria; fuel prices in Bavaria; Environmental regulations in Germany; small boiler markets in Germany; Energy consumption in Austria; small-scale utilization of wood fuels; utilization of wood energy. (Slides, additional information from the author)

  10. Wood Fingerprints:Recognition of Sawn Wood Products

    OpenAIRE

    Pahlberg, Tobias

    2014-01-01

    This thesis deals with wood fingerprints and presents ways to track sawn wood products through an industrial process using cameras. The possibility to identify individual wood products comes from the biological variation of the trees, where the genetic code, environment and breakdown process creates a unique appearance for every board. This application has much of the same challenges as are found in human biometrics applications.The vision for the future is to be able to utilize existing imag...

  11. Radiographic testing of wood

    International Nuclear Information System (INIS)

    Osterloh, K.; Zscherpel, U.; Raedel, C.; Weidemann, G.; Meinel, D.; Goebbels, J.; Ewert, U.; Hasenstab, A.; Buecherl, T.

    2007-01-01

    Wood is an old and established consumption and construction material. It is still the most common material for constructing furniture, roofs, playgrounds and mine supports. In contrast to steel and concrete, wood warns of extreme loads by creaking. Its mechanical stability is more influenced by decay than by peripheral cracks. While external cracks are visible, internal decay by fungus growth is undetectable from outside. This may be a safety problem in supporting structures. The best analysis of the internal structure is provided by computed tomography, but this is also the most complex method, much more so than simple radiographic testing. However, the latter is made inaccurate by scattered radiation resulting from internal moisture. With the image processing options of digital radiographic techniques, the structural information can be separated effectively from noise. In contrast to X-ray and gamma radiography, neutron radiography provides information on the spatial distribution of moisture. In healthy wood, water is conducted in the sapwood while the hardwood is dry. Moisture in hardwood is caused by infestations, e.g. fungus growth. The contribution presents a comparative analysis of the available radiographic methods. (orig.)

  12. European wood-fuel trade

    International Nuclear Information System (INIS)

    Hillring, B.; Vinterbaeck, J.

    2001-01-01

    This paper discusses research carried out during the l990s on European wood fuel trade at the Department of Forest Management and Products, SLU, in Sweden. Utilisation of wood-fuels and other biofuels increased very rapidly in some regions during that period. Biofuels are replacing fossil fuels which is an effective way to reduce the future influence of green house gases on the climate. The results indicate a rapid increase in wood-fuel trade in Europe from low levels and with a limited number of countries involved. The chief products traded are wood pellets, wood chips and recycled wood. The main trading countries are, for export, Germany and the Baltic states and, for import, Sweden, Denmark and to some extent the Netherlands. In the future, the increased use of biofuel in European countries is expected to intensify activity in this trade. (orig.)

  13. Diffraction. Powder, amorphous, liquid

    International Nuclear Information System (INIS)

    Sosnowska, I.M.

    1999-01-01

    Neutron powder diffraction is a unique tool to observe all possible diffraction effects appearing in crystal. High-resolution neutron diffractometers have to be used in this study. Analysis of the magnetic structure of polycrystalline materials requires the use of high-resolution neutron diffraction in the range of large interplanar distances. As distinguished from the double axis diffractometers (DAS), which show high resolution only at small interplanar distances, TOF (time-of-flight) diffractometry offers the best resolution at large interplanar distances. (K.A.)

  14. Characteristics of Inconel Powders for Powder-Bed Additive Manufacturing

    OpenAIRE

    Quy Bau Nguyen; Mui Ling Sharon Nai; Zhiguang Zhu; Chen-Nan Sun; Jun Wei; Wei Zhou

    2017-01-01

    In this study, the flow characteristics and behaviors of virgin and recycled Inconel powder for powder-bed additive manufacturing (AM) were studied using different powder characterization techniques. The results revealed that the particle size distribution (PSD) for the selective laser melting (SLM) process is typically in the range from 15 μm to 63 μm. The flow rate of virgin Inconel powder is around 28 s·(50 g)−1. In addition, the packing density was found to be 60%. The rheological test re...

  15. Biomimetic studies of wood decay: Simulating the effect of low molecular weight compounds and fungal enzymes

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Jellison, Jody

    The effect of FeCl3 (Fe3+), hydrogen peroxide (H2O2), a low molecular weight compound (2,3- Dihydroxybenzoic acid), and oxalic acid on wood were tested in a study designed to mimic wood degradation by brown rot fungi. Previous studies suggest that these components are involved in the early stages...... of brown rot decay where they catalyze the formation of hydroxyl radicals through the Fenton reaction or related mechanisms. However, the separate and combined effects of these individual chemical components on wood have not been thoroughly investigated. Tests were conducted in Erlenmeyer flasks containing...... 50 ml of 40 mM acetate buffer (pH 4.5), white pine wood powder and varying combinations of the chemicals previously mentioned. Changes in cellulose crystallinity were analyzed by X-ray diffraction using a ¿-2¿ scan. Findings suggest that iron, H2O2, chelators and oxalic acid may affect over all...

  16. Biomimetic studies of wood decay: Simulating the effect of low molecular weight compounds and fungal enzymes

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Jellison, Jody

    50 ml of 40 mM acetate buffer (pH 4.5), white pine wood powder and varying combinations of the chemicals previously mentioned. Changes in cellulose crystallinity were analyzed by X-ray diffraction using a ¿-2¿ scan. Findings suggest that iron, H2O2, chelators and oxalic acid may affect over all......The effect of FeCl3 (Fe3+), hydrogen peroxide (H2O2), a low molecular weight compound (2,3- Dihydroxybenzoic acid), and oxalic acid on wood were tested in a study designed to mimic wood degradation by brown rot fungi. Previous studies suggest that these components are involved in the early stages...... of brown rot decay where they catalyze the formation of hydroxyl radicals through the Fenton reaction or related mechanisms. However, the separate and combined effects of these individual chemical components on wood have not been thoroughly investigated. Tests were conducted in Erlenmeyer flasks containing...

  17. Controlling mold on wood Pallets

    Science.gov (United States)

    Carol A. Clausen

    2012-01-01

    THE WOOD PALLET AND CONTAINER INDUSTRY CONSUMES 4.5 billion board feet (BBF) of hardwoods and 1.8 BBF of softwoods for the annual production of 400-500 million solid wood pallets. While alternative materials such as plastic, corrugated paperboard and metal have entered the market, solid wood remains the material of choice for a majority of pallets on the market (more...

  18. Inoculation Expedition of Agar wood

    International Nuclear Information System (INIS)

    Peng, C.S.; Mohd Fajri Osman; Rusli Zakaria

    2015-01-01

    Inoculation expedition of agar wood is a main field works for researcher in Nuclear Malaysia to prove the real inoculation of agar wood in real jungle. These expeditions was conducted fourth times in the jungles of Malaysia including Gunung Tebu in Terengganu, Murum in Belaga, Sarawak, Kampung Timbang in Kota Belud, Sabah and Nuclear Malaysia itself. This expedition starts from preparation of samples and equipment, transportation into the jungle, searching and recognition of agar wood and lastly, inoculation of the agar wood. Safety aspects precedence set out in the preparation and implementation of this expedition. (author)

  19. NANOCOATING PROCESS FOR TEXTILES APPLICATIONS AND WOOD PROTECTION

    Directory of Open Access Journals (Sweden)

    NICULESCU Claudia

    2014-05-01

    Full Text Available This paper presents the research results obtained in ERA NET MANUCOAT project, coordinated by INCDTP in collaboration with the following partners: INCDMNR-IMNR, SC MGM STAR CONSTRUCT SRL –Romania and IRIS-Spain. The objective of the research was to develop and obtain textile and wood surfaces with self-cleaning, photo catalytic, antibacterial and antifungal properties. An innovative method of manufacturing nanoparticles by hydrothermal process in a single step without any further heat treatment and controlled stoichiometry, tested spray coating technology (sputtering were developed. Full characterization of nanostructured powders in terms of chemical, physical, structural, thermal and technological characteristics was performed. The most important features to be considered in the treatment of wood by sputtering in order to deposit thin layers of TiO2 NPs or TiO2/Ag as the humidity should be below 12% and the maximum roughness P150, depending on the species of wood. Future works envisage optimizing the existing sputtering systems for pilot stage, in order to make nanoparticles deposits on large areas of textile and wood. The results of the research are photocatalytic textiles for surgical gowns, operative fields, hospital bed sheets and curtains and drapes for public spaces.

  20. Parametric Powder Diffraction

    Science.gov (United States)

    David, William I. F.; Evans, John S. O.

    The rapidity with which powder diffraction data may be collected, not only at neutron and X-ray synchrotron facilities but also in the laboratory, means that the collection of a single diffraction pattern is now the exception rather than the rule. Many experiments involve the collection of hundreds and perhaps many thousands of datasets where a parameter such as temperature or pressure is varied or where time is the variable and life-cycle, synthesis or decomposition processes are monitored or three-dimensional space is scanned and the three-dimensional internal structure of an object is elucidated. In this paper, the origins of parametric diffraction are discussed and the techniques and challenges of parametric powder diffraction analysis are presented. The first parametric measurements were performed around 50 years ago with the development of a modified Guinier camera but it was the automation afforded by neutron diffraction combined with increases in computer speed and memory that established parametric diffraction on a strong footing initially at the ILL, Grenoble in France. The theoretical parameterisation of quantities such as lattice constants and atomic displacement parameters will be discussed and selected examples of parametric diffraction over the past 20 years will be reviewed that highlight the power of the technique.

  1. Quantifying arthropod contributions to wood decay

    Science.gov (United States)

    Michael Ulyshen; Terry Wagner

    2013-01-01

    Termites carry large amounts of soil into dead wood, and this behaviour complicates efforts to measure their contributions to wood decay. A novel method for isolating termite soil by burning the wood is described, and some preliminary results are presented.

  2. Corrosion of Fasteners in Wood Treated with Newer Wood Preservatives

    Science.gov (United States)

    Samuel L. Zelinka

    2013-01-01

    This document compiles recent research findings related to corrosion of metals in preservative treated wood into a single report on corrosion of metals in wood. The research was conducted as part of the Research, Technology and Education portion of the National Historic Covered Bridge Preservation (NHCBP) Program administered by the Federal Highway Administration. The...

  3. Wood pole overhead lines

    CERN Document Server

    Wareing, Brian

    2005-01-01

    This new book concentrates on the mechanical aspects of distribution wood pole lines, including live line working, environmental influences, climate change and international standards. Other topics include statutory requirements, safety, profiling, traditional and probabilistic design, weather loads, bare and covered conductors, different types of overhead systems, conductor choice, construction and maintenance. A section has also been devoted to the topic of lightning, which is one of the major sources of faults on overhead lines. The book focuses on the effects of this problem and the strate

  4. [Effects of spectral pretreatment on the prediction of crystallinity of wood cellulose using near infrared spectroscopy].

    Science.gov (United States)

    Jiang, Ze-hui; Fei, Ben-hua; Yang, Zhong

    2007-03-01

    The crystallinity of wood has an important effect on the physical, mechanical and chemical properties of cellulose fibers. The aims of this study were to investigate the ability of near infrared spectroscopy (NIR) to predict the crystallinity of wood cellulose and the effect of spectral pretreatment on the prediction of crystallinity in wood cellulose using near infrared spectroscopy (NIR). Near infrared diffuse reflectance spectra were collected from wood powder with a fiber-optical probe and the crystallinity of wood was determined by X-ray diffractometer (XRD) in this experiment. The results showed that near infrared spectroscopy coupled with partial least square (PLS) regression could be correlated with the crystallinity of plantation wood, and the ability of NIR prediction based on original spectra was better than that based on the first derivative or second derivative treated spectra. There was a significant correlation between NIR spectra and XRD determined crystallinity with a correlationcoefficient of 0.950 and a low RMSEP. Near infrared spectroscopy coupled with multivariate data anlaysis has proven to be an accurate and fast method for rapid prediction of wood crystallinity.

  5. Preservation of forest wood chips

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, P.D.; Thomsen, I.M.; Ohlsson, C.; Leer, E.; Ravn Schmidt, E.; Soerensen, M.; Knudsen, P.

    1999-01-01

    As part of the Danish Energy Research Programme on biomass utilisation for energy production (EFP), this project concerns problems connected to the handling and storing of wood chips. In this project, the possibility of preserving wood chips of the Norway Spruce (Picea Abies) is addressed, and the potential improvements by anaerobic storage are tested. Preservation of wood chips aims at reducing dry matter losses from extensive heating during storage and to reduce production of fungal spores. Fungal spores pose a health hazards to workers handling the chips. Further the producers of wood chips are interested in such a method since it would enable them to give a guarantee for the delivery of homogeneous wood chips also during the winter period. Three different types of wood chips were stored airtight and further one of these was stored in accordance with normal practise and use as reference. The results showed that airtight storage had a beneficial impact on the quality of the chips: no redistribution of moisture, low dry matter losses, unfavourable conditions for microbial activity of most fungi, and the promotion of yeasts instead of fungi with airborne spores. Likewise the firing tests showed that no combustion problems, and no increased risk to the environment or to the health of staff is caused by anaerobic storage of wood chips. In all, the tests of the anaerobic storage method of forest wood chips were a success and a large-scale test of the method will be carried out in 1999. (au)

  6. Properties of seven Colombian woods

    Science.gov (United States)

    B. A. Bendtsen; M. Chudnoff

    1981-01-01

    Woods from abroad are an important raw material to the forest products industries in the United States. A major concern in effective utilization of this resource is the lack of technical information on many species. This report presents the results of an evaluation of the mechanical properties of small, clear specimens of seven Colombian woods. These results are...

  7. Moisture transport in coated wood

    NARCIS (Netherlands)

    Meel, P.A. van; Erich, S.J.F.; Huinink, H.P.; Kopinga, K.; Jong, J. DE; Adan, O.C.G.

    2011-01-01

    Moisture accumulation inside wood causes favorable conditions for decay. Application of a coating alters the moisture sorption of wood and prevents accumulation of moisture. This paper presents the results of a nuclear magnetic resonance (NMR) study on the influence of a coating on the moisture

  8. The sustainable wood production initiative.

    Science.gov (United States)

    Robert. Deal

    2004-01-01

    To address concerns about sustainable forestry in the region, the Focused Science Delivery Program is sponsoring a three year Sustainable Wood Production Initiative. The Pacific Northwest is one of the world's major timber producing regions, and the ability of this region to produce wood on a sustained yield basis is widely recognized. Concerns relating to the...

  9. Measuring wood specific gravity, correctly

    Science.gov (United States)

    G. Bruce Williamson; Michael C. Wiemann

    2010-01-01

    The specific gravity (SG) of wood is a measure of the amount of structural material a tree species allocates to support and strength. In recent years, wood specific gravity, traditionally a forester’s variable, has become the domain of ecologists exploring the universality of plant functional traits and conservationists estimating global carbon stocks. While these...

  10. On Erdos–Wood's conjecture

    Indian Academy of Sciences (India)

    In this article, we prove that infinite number of integers satsify Erdős–Woods conjecture. Moreover, it follows that the number of natural numbers ≤ satisfies Erdős–Woods conjecture with = 2 is at least /(log ) for some positive constant > 2.

  11. Composites from wood and plastics

    Science.gov (United States)

    Craig Clemons

    2010-01-01

    Composites made from thermoplastics and fillers or reinforcements derived from wood or other natural fibers are a dynamic research area encompassing a wide variety of composite materials. For example, as the use of biopolymers grows, wood and other natural fiber sources are being investigated as renewable sources of fillers and reinforcements to modify performance....

  12. The wood of Merovingian weaponry

    Czech Academy of Sciences Publication Activity Database

    Tegel, W.; Muigg, B.; Büntgen, Ulf

    2016-01-01

    Roč. 65, JAN (2016), s. 148-153 ISSN 0305-4403 R&D Projects: GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : Early Middle Ages * Merovingian weaponry * Mineralised wood * Wood anatomy Subject RIV: EH - Ecology, Behaviour Impact factor: 2.602, year: 2016

  13. Public opinion and wood energy

    Science.gov (United States)

    Sarah Hitchner; John Schelhas; Teppo Hujala; J. Peter Brosius

    2014-01-01

    As wood-based bioenergy continues to develop around the world, it will utilize forestlands in new ways and will have different effects on a number of stakeholders, including forest landowners, local communities, extant industries, policymakers, investors, and others. As more stakeholders become involved in the wood energy web, and as the general public becomes more...

  14. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

    The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...... for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition...

  15. Origin of Petrified Wood Color

    Directory of Open Access Journals (Sweden)

    George Mustoe

    2016-05-01

    Full Text Available Fossil forests have world-wide distribution, commonly preserving mineralized wood that displays vivid hues and complex color patterns. However, the origin of petrified color has received little scientific attention. Color of silicified wood may be influenced by the presence of relict organic matter, but the most significant contribution comes from trace metals. This study reports quantitative analysis of trace metals in 35 silicified wood samples, determined using LA-ICP-MS spectrometry. The most important of these metals is Fe, which can produce a rainbow of hues depending on its abundance and oxidation state. Cr is the dominant colorant for bright green fossil wood from Arizona, USA and Zimbabwe, Africa. Complex color patterns result from the progressive nature of the fossilization process, which causes wood to have varying degrees of permeability during successive episodes of permineralization. These processes include simple diffusion, chromatographic separation, infiltration of groundwater along fractures and void spaces, and oxidation/reduction.

  16. Nuclear fuel powder transfer device

    International Nuclear Information System (INIS)

    Komono, Akira

    1998-01-01

    A pair of parallel rails are laid between a receiving portion to a molding portion of a nuclear fuel powder transfer device. The rails are disposed to the upper portion of a plurality of parallel support columns at the same height. A powder container is disposed while being tilted in the inside of the vessel main body of a transfer device, and rotational shafts equipped with wheels are secured to right and left external walls. A nuclear powder to be mixed, together with additives, is supplied to the powder container of the transfer device. The transfer device engaged with the rails on the receiving side is transferred toward the molding portion. The wheels are rotated along the rails, and the rotational shafts, the vessel main body and the powder container are rotated. The nuclear powder in the tilted powder container disposed is rotated right and left and up and down by the rotation, and the powder is mixed satisfactory when it reaches the molding portion. (I.N.)

  17. Projected wood energy impact on US forest wood resources

    Energy Technology Data Exchange (ETDEWEB)

    Skog, K.E. [USDA Forest Service, Madison, WI (United States)

    1993-12-31

    The USDA Forest Service has developed long-term projections of wood energy use as part of a 1993 assessment of demand for and supply of resources from forest and range lands in the United States. To assess the impact of wood energy demand on timber resources, a market equilibrium model based on linear programming was developed to project residential, industrial, commercial, and utility wood energy use from various wood energy sources: roundwood from various land sources, primary wood products mill residue, other wood residue, and black liquor. Baseline projections are driven by projected price of fossil fuels compared to price of wood fuels and the projected increase in total energy use in various end uses. Wood energy use is projected to increase from 2.67 quad in 1986 to 3.5 quad in 2030 and 3.7 quad in 2040. This is less than the DOE National Energy Strategy projection of 5.5 quad in 2030. Wood energy from forest sources (roundwood) is projected to increase from 3.1 billion (10{sup 9}) ft{sup 3} in 1986 to 4.4. billion ft{sup 3} in 2030 and 4.8 billion ft{sup 3} in 2040 (88, 124 and 136 million m{sup 3}, respectively). This rate of increase of roundwood use for fuel -- 0.8 percent per year -- is virtually the same as the projected increase rate for roundwood for pulpwood. Pulpwood roundwood is projected to increase from 4.2 billion ft{sup 3} in 1986 to 6.0 billion ft{sup 3} in 2030 and 6.4 billion ft{sup 3} in 2040 (119, 170 and 183 million m{sup 3}, respectively).

  18. Wood power in North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, J.G.; Guessous, L. [Research Triangle Institute, Research Triangle Park, NC (United States)

    1993-12-31

    North Carolina (NC) is one of the most forested states, and supports a major wood products industry. The NC Department of Natural Resources sponsored a study by Research Triangle Institute to examine new, productive uses of the State`s wood resources, especially electric power generation by co-firing with coal. This paper summarizes our research of the main factors influencing wood power generation opportunities, i.e., (1) electricity demand; (2) initiative and experience of developers; (3) available fuel resources; (4) incentives for alternate fuels; and (5) power plant technology and economics. The results cover NC forests, short rotation woody crops, existing wood energy facilities, electrical power requirements, and environmental regulations/incentives. Quantitative assessments are based on the interests of government agencies, utilities, electric cooperatives, developers and independent power producers, forest products industries, and the general public. Several specific, new opportunities for wood-to-electricity in the State are identified and described. Comparisons are made with nationwide resources and wood energy operations. Preferred approaches in NC are co-generation in existing or modified boilers and in dedicated wood power plants in forest industry regions. Co-firing is mainly an option for supplementing unreliable primary fuel supplies to existing boilers.

  19. Cooling of wood briquettes

    Directory of Open Access Journals (Sweden)

    Adžić Miroljub M.

    2013-01-01

    Full Text Available This paper is concerned with the experimental research of surface temperature of wood briquettes during cooling phase along the cooling line. The cooling phase is an important part of the briquette production technology. It should be performed with care, otherwise the quality of briquettes could deteriorate and possible changes of combustion characteristics of briquettes could happen. The briquette surface temperature was measured with an IR camera and a surface temperature probe at 42 sections. It was found that the temperature of briquette surface dropped from 68 to 34°C after 7 minutes spent at the cooling line. The temperature at the center of briquette, during the 6 hour storage, decreased to 38°C.

  20. Preparation of superconductor precursor powders

    Science.gov (United States)

    Bhattacharya, Raghunath; Blaugher, Richard D.

    1995-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of thallium in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  1. Wood would burn

    International Nuclear Information System (INIS)

    Swithenbank, Jim; Chen, Qun; Zhang, Xiaohui; Sharifi, Vida; Pourkashanian, Mohamed

    2011-01-01

    Absract: In view of the world-wide problem of energy sustainability and greenhouse gas production (carbon dioxide), it is timely to review the issues involved in generating heat and power from all fuels and especially new (to the UK) solid fuels, including high moisture fuels such as wood, SRF, oil shale, tar sands and brown coal, which will become major international fuels as oil and gas become depleted. The combustion properties of some of these materials are significantly different from traditional coal, oil and gas fuels, however the technology proposed herein is also applicable to these conventional fuels. This paper presents some innovative combustion system options and the associated technical factors that must be considered for their implementation. For clarity of understanding, the novel concepts will be largely presented in terms of a currently developing solid fuel market; biomass wood chips. One of the most important characteristics of many solid fuels to be used in the future (including oil shale and brown coal) is their high moisture content of up to 60%. This could be removed by utilising low grade waste heat that is widely available in industry to dry the fuel and thus reduce transport costs. Burning such dried wood for power generation also increases the energy available from combustion and thus acts as a thermal transformer by upgrading the low grade heat to heat available at combustion temperatures. The alternative approach presented here is to recover the latent heat by condensing the extrinsic moisture and the water formed during combustion. For atmospheric combustion, the temperature of the condensed combustion products is below the dew point at about 55-65 o C and is only suitable for recovery in an efficient district heating system. However, in order to generate power from the latent heat, the condensation temperature must be increased to the level where the heat can be used in the thermodynamic power cycle. This can be achieved by

  2. The Carbon Impacts of Wood Products

    Science.gov (United States)

    Richard Bergman; Maureen Puettmann; Adam Taylor; Kenneth E. Skog

    2014-01-01

    Wood products have many environmental advantages over nonwood alternatives. Documenting and publicizing these merits helps the future competitiveness of wood when climate change impacts are being considered. The manufacture of wood products requires less fossil fuel than nonwood alternative building materials such as concrete, metals, or plastics. By nature, wood is...

  3. Treatments that enhance physical properties of wood

    Science.gov (United States)

    Roger M. Rowell; Peggy Konkol

    1987-01-01

    This paper was prepared for anyone who wants to know more about enhancing wood’s physical properties, from the amateur wood carver to the president of a forest products company. The authors describe chemical and physical treatments of wood that enhance the strength, stiffness, water repellency, and stability of wood. Five types of treatments are described: 1. water-...

  4. Physical properties and moisture relations of wood

    Science.gov (United States)

    William Simpson; Anton TenWolde

    1999-01-01

    The versatility of wood is demonstrated by a wide variety of products. This variety is a result of a spectrum of desirable physical characteristics or properties among the many species of wood. In many cases, more than one property of wood is important to the end product. For example, to select a wood species for a product, the value of appearance- type properties,...

  5. Moisture relations and physical properties of wood

    Science.gov (United States)

    Samuel V. Glass; Samuel L. Zelinka

    2010-01-01

    Wood, like many natural materials, is hygroscopic; it takes on moisture from the surrounding environment. Moisture exchange between wood and air depends on the relative humidity and temperature of the air and the current amount of water in the wood. This moisture relationship has an important influence on wood properties and performance. Many of the challenges of using...

  6. Wood Flour Moulding Technology: Implications for Technical ...

    African Journals Online (AJOL)

    User

    2011-04-19

    Apr 19, 2011 ... selected dry wood by grinding. Interest in this modern industrial practice in wood anchors ... flour moulding technology minimizes atmospheric pollution, reduces cost of wood waste disposal and curbs, ... Zhang and Wolcott,. 2007). Wood Flour Moulding Technology: Implications for Technical Education ...

  7. Fire Safety Design of Wood Structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2006-01-01

    Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections.......Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections....

  8. Wood-based composites and panel products

    Science.gov (United States)

    John A. Youngquist

    1999-01-01

    Because wood properties vary among species, between trees of the same species, and between pieces from the same tree, solid wood cannot match reconstituted wood in the range of properties that can be controlled in processing. When processing variables are properly selected, the end result can sometimes surpass nature’s best effort. With solid wood, changes in...

  9. Wood Technology: Techniques, Processes, and Products

    Science.gov (United States)

    Oatman, Olan

    1975-01-01

    Seven areas of wood technology illustrates applicable techniques, processes, and products for an industrial arts woodworking curriculum. They are: wood lamination; PEG (polyethylene glycol) diffusion processes; wood flour and/or particle molding; production product of industry; WPC (wood-plastic-composition) process; residential construction; and…

  10. FIRE INSURANCE AND WOOD SCHOOL BUILDINGS.

    Science.gov (United States)

    PURCELL, FRANK X.

    A COMPARISON OF FIRE INSURANCE COSTS OF WOOD, MASONRY, STEEL AND CONCRETE STRUCTURES SHOWS FIRE INSURANCE PREMIMUMS ON WOOD STRUCTURES TEND TO BE HIGHER THAN PREMIUMS ON MASONRY, STEEL AND CONCRETE BUILDINGS, HOWEVER, THE INITIAL COST OF THE WOOD BUILDINGS IS LOWER. DATA SHOW THAT THE SAVINGS ACHIEVED IN THE INITIAL COST OF WOOD STRUCTURES OFFSET…

  11. The challenge of bonding treated wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    Wood products are quite durable if exposure to moisture is minimized; however, most uses of wood involve considerable exposure to moisture. To preserve the wood, chemicals are used to minimize moisture pickup, to prevent insect attack, and/or to resist microbial growth. The chemicals used as preservatives can interfere with adhesive bonds to wood. Given the many...

  12. Combustion properties of wood impregnated with commercial ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... ... thermal conductivity and the fact that wood char is formed when wood is burned. In order to reduce flammability and provide safety, wood is treated with fire-retardant chemicals. In other words, the combustibility of wood may be reduced with flame- retardant or fire-retardant materials (Nussbaum, 1988;.

  13. (TECTONA GRANDIS LEAF POWDER

    Directory of Open Access Journals (Sweden)

    Yash Mishra

    2015-01-01

    Full Text Available In this study, the adsorption potential of Teak (Tectona grandis leaf powder (TLP toremove Methylene blue (MB and Malachite Green (MG dye molecules from aqueoussolution was investigated. Batch experiments were conducted to evaluate the influenceof operational parameters such as, pH (2−9, adsorbent dosage (1−7 g/L, contact time(15−150 minutes and initial dye concentration (20−120 mg/L at stirring speed of 150rpm for the adsorption of MB and MG on TLP. Maximum removal efficiency of 98.4%and 95.1% was achieved for MB and MG dye, respectively. The experimentalequilibrium data were analysed using Langmuir, Freundlich and Temkin isothermmodels and it was found that, it fitted well to the Freundlich isotherm model. Thesurface structure and morphology of the adsorbent was characterized using scanningelectron microscopy (SEM and the presence of functional groups and its interactionwith the dye molecules were analysed using Fourier transform infrared spectroscopy(FTIR. Based on the investigation, it has been demonstrated that the teak leaf powderhas good potential for effective adsorption of methylene blue and malachite green dye.

  14. Potential wood protection strategies using physiological requirements of wood degrading fungi

    NARCIS (Netherlands)

    Sailer, M.F.; Etten, B.D. van

    2004-01-01

    Due to the increasing restrictions in the use of wood preserving biocides a number of potential biocide free wood preserving alternatives are currently assessed. Wood degrading fungi require certain conditions in the wood in order to be able to use wood as a food source. This paper discusses the

  15. COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

    Directory of Open Access Journals (Sweden)

    Yalçın ÖRS

    1999-03-01

    Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

  16. Electron Microscopy Observation of Biomineralization within Wood Tissues of Kurogaki

    Directory of Open Access Journals (Sweden)

    Kazue Tazaki

    2017-07-01

    Full Text Available Interactions between minerals and microorganisms play a crucial role in living wood tissues. However, living wood tissues have never been studied in the field. Fortunately, we found several kurogaki (black persimmon; Diospyros kaki trees at Tawara in Kanazawa, Ishikawa, Japan. Here, we report the characterization of kurogaki based on scanning electron microscopy equipped with energy-dispersive spectroscopy (SEM-EDS and transmission electron microscopy (TEM, associated with inductively coupled plasma-mass spectrometry (ICP-MS analyses, X-ray fluorescence analyses (XRF and X-ray powder diffraction (XRD analyses. This study aims to illustrate the ability of various microorganisms associated with biominerals within wood tissues of kurogaki, as shown by SEM-EDS elemental content maps and TEM images. Kurogaki grows very slowly and has extremely hard wood, known for its striking black and beige coloration, referred to as a “peacock pattern”. However, the scientific data for kurogaki are very limited. The black “peacock pattern” of the wood mainly comprises cellulose and high levels of crystal cristobalite. As per the XRD results, the black taproot contains mineralized 7 Å clays (kaolinite, cellulose, apatite and cristobalite associated with many microorganisms. The chemical compositions of the black and beige portions of the black persimmon tree were obtained by ICP-MS analyses. Particular elements such as abundant Ca, Mg, K, P, Mn, Ba, S, Cl, Fe, Na, and Al were concentrated in the black region, associated with Pb and Sr elements. SEM-EDS semi-qualitative analyses of kurogaki indicated an abundance of P and Ca in microorganisms in the black region, associated with Pb, Sr, S, Mn, and Mg elements. On the other hand, XRF and XRD mineralogical data showed that fresh andesite, weathered andesite, and the soils around the roots of kurogaki correlate with biomineralization of the black region in kurogaki roots, showing clay minerals (kaolinite and

  17. Women's work... in wood products

    Science.gov (United States)

    Janice K. Wiedenbeck

    1998-01-01

    Women have opportunities galore in the 1990s in wood products research, education, extension, consulting,manufacturing, marketing, and associations in North America. In the 1980s the same statement could not have been made.

  18. Wood and Paper Manufacturing Sectors

    Science.gov (United States)

    Find EPA regulatory information for the wood product and paper manufacturing sectors, including paper, pulp and lumber. Information includes NESHAPs and effluent guidelines for pulp and paper rulemaking, and compliance guidelines

  19. Wood-burning stoves worldwide

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo

    were suggested to facilitate the transition to cleaner wood-burning regimes. Considering that 40% of the world population continues relying on traditional forms of wood-burning, the design and dissemination of cleaner technologies of WBSs constitute relevant strategies to mitigate global climate...... of improved stoves. In the Brazilian case study, it was observed that the kitchen concentrations of PM2.5 monitored during wood cooking events increased by more than 10 times in relation to the background levels due to the improper use and maintenance of the studied ICSs (rocket stoves). In Southern Europe...... to facilitate the transition to more intelligent modes of using WBSs by: 1st training solid-fuel users to better operate and maintain existing installations, 2nd harmonizing wood-burning regulations to address the use of seasoned fuels, certified stoves and functioning chimneys; 3rd designing applications...

  20. Neutron Powder Diffraction in Sweden

    International Nuclear Information System (INIS)

    Tellgren, R.

    1986-01-01

    Neutron powder diffraction in Sweden has developed around the research reactor R2 in Studsvik. The article describes this facility and presents a historical review of research results obtained. It also gives some ideas of plans for future development

  1. Rotary powder feed through apparatus

    Science.gov (United States)

    Lewis, Gary K.; Less, Richard M.

    2001-01-01

    A device for increasing the uniformity of solids within a solids fabrication system, such as a direct light fabrication (DLF) system in which gas entrained powders are passed through the focal point of a moving high-power light which fuses the particles in the powder to a surface being built up in layers. The invention provides a feed through interface wherein gas entrained powders input from stationary input lines are coupled to a rotating head of the fabrication system. The invention eliminates the need to provide additional slack in the feed lines to accommodate head rotation, and therefore reduces feed line bending movements which induce non-uniform feeding of gas entrained powder to a rotating head.

  2. Phonons from neutron powder diffraction

    Science.gov (United States)

    Dimitrov, D. A.; Louca, D.; Röder, H.

    1999-09-01

    The spherically averaged structure function S(\\|q\\|) obtained from pulsed neutron powder diffraction contains both elastic and inelastic scattering via an integral over energy. The Fourier transformation of S(\\|q\\|) to real space, as is done in the pair density function (PDF) analysis, regularizes the data, i.e., it accentuates the diffuse scattering. We present a technique which enables the extraction of off-center (\\|q\\|≠0) phonon information from powder diffraction experiments by comparing the experimental PDF with theoretical calculations based on standard interatomic potentials and the crystal symmetry. This procedure [dynamics from powder diffraction] has been successfully implemented as demonstrated here for two systems, a simple metal fcc Ni and an ionic crystal CaF2. Although computationally intensive, this data analysis allows for a phonon based modeling of the PDF, and additionally provides off-center phonon information from neutron powder diffraction.

  3. Dry and coating of powders

    International Nuclear Information System (INIS)

    Alonso, M.; Alguacil, F. J.

    1999-01-01

    This paper presents a review on the mixing and coating of powders by dry processes. The reviews surveys fundamental works on mixture characterization (mixing index definitions and sampling techniques), mixing mechanisms and models, segregation with especial emphasis on free-surface segregation, mixing of cohesive powders and interparticle forces, ordered mixing (dry coating) including mechanism, model and applications and mixing equipment selection. (Author) 180 refs

  4. Powder collection apparatus/method

    Science.gov (United States)

    Anderson, I.E.; Terpstra, R.L.; Moore, J.A.

    1994-01-11

    Device for separating and collecting ultrafine atomized powder from the gas stream of a gas atomizing apparatus comprises a housing having an interior wall oriented at an angle relative to horizontal so as to form a downwardly converging, conical expansion chamber, an inlet conduit communicated to the expansion chamber proximate an upper region thereof for receiving the gas stream, and an outlet proximate a lower region of the expansion chamber. The inlet conduit is oriented at a compound inclined angle (with respect to horizontal) selected to promote separation and collection of powder from the gas stream in the expansion chamber. The compound angle comprises a first entrance angle that is greater than the angle of repose of the powder on the housing interior wall such that any powder accumulation in the inlet conduit tends to flow down the wall toward the outlet. The second angle is selected generally equal to the angle of the housing interior wall measured from the same horizontal plane so as to direct the gas stream into the expansion chamber generally tangent to the housing interior wall to establish a downward swirling gas stream flow in the expansion chamber. A powder collection container is communicated to the outlet of the expansion chamber to collect the powder for further processing. 4 figures.

  5. Structure and shear in a cohesive powder

    NARCIS (Netherlands)

    Janssen, R.J.M.

    2001-01-01

    Handling of powders and granular materials is of great importance to industry. However, the knowledge of many powder related processes in industry is poor. In this work, the flow behaviour of powder has been investigated with an advanced tester: the Flexible Wall Biaxial Tester. Flow of powder

  6. The effect of air temperature on the sappan wood extract drying

    Science.gov (United States)

    Djaeni, M.; Triyastuti, M. S.; Asiah, N.; Annisa, A. N.; Novita, D. A.

    2015-12-01

    The sappan wood extract contain natural colour called brazilin that can be used as a food colouring and antioxidant. The product is commonly found as a dry extract powder for consummer convenience. The spray dryer with air dehumidification can be an option to retain the colour and antioxidant agent. This paper discusses the effect of air temperature on sappan wood extract drying that was mixed with maltodextrin. As responses, the particle size, final moisture content, and extract solubility degradation were observed. In all cases, the process conducted in temperature ranging 90 - 110°C can retain the brazilin quality as seen in solubility and particle size. In addition, the sappan wood extract can be fully dried with moisture content below 2%. Moreover, with the increase of air temperature, the particle size of dry extract can be smaller.

  7. Robert Williams Wood: pioneer of invisible light.

    Science.gov (United States)

    Sharma, Shruti; Sharma, Amit

    2016-03-01

    The Wood's lamp aids in the diagnosis of multiple infectious, inflammatory and neoplastic dermatologic conditions. Although the Wood's lamp has many applications, which have improved both the diagnosis and management of disease, the man credited for its invention is relatively unknown in medicine. Robert Williams Wood, a prominent physicist of the early 20th century, is credited for the invention of the Wood's lamp. Wood was the father of infrared and ultraviolet photography and made significant contributions to other areas in optics and spectroscopy. Wood's work encompassed the formative years of American Physics; he published over 200 original papers over his lifetime. A few years after the invention of the Wood's lamp for ultraviolet photography, physicians in Europe adopted the Wood's lamp for dermatologic applications. Wood's lamp remains popular in clinics globally, given its ease of use and ability to improve diagnostic precision. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. On the Methods to Measure Powder Flow.

    Science.gov (United States)

    Tan, Geoffrey; Morton, David A V; Larson, Ian

    2015-01-01

    The flow of powders can often play a critical role in the manufacturing of pharmaceutical products. Many of these processes require good, consistent and predictable flow of powders to ensure continuous production of pharmaceutical dosages and to ensure their quality. Therefore, the flow of powders is of paramount importance to the pharmaceutical industry and thus the measuring and evaluating of powder flow is of utmost importance. At present, there are numerous methods in which the flow of powders can be measured. However, due to the complex and environment-dependent nature of powders, no one method exists that is capable of providing a complete picture of the behaviour of powders under dynamic conditions. Some of the most commonly applied methods to measure the flow of powders include: density indices, such as the Carr index and Hausner ratio, powder avalanching, the angle of repose (AOR), flow through an orifice, powder rheometry and shear cell testing.

  9. The use of X-ray diffraction for analyzing biomodification of crystalline cellulose by wood decay fungi

    DEFF Research Database (Denmark)

    Howell, Caitlin; Hastrup, Anne Christine Steenkjær; Jellison, Jody

    2007-01-01

    X-ray diffraction (XRD) is based on the creation of an interference pattern by x-rays when they encounter a regularly spaced matrix. In wood, this process has been used to determine, among other things, the average width of the cellulose microcrystals, the percent of crystalline cellulose within...... measures. Studies were conducted to determine changes over time in wood crystallinity generated by the brown rot fungus Meruliporia incrassata and the soft rot fungus Chaetomium elatum. Fungi were grown in modified soil block jars with spruce wood blocks for 2, 4, 6, and 8 weeks. After removal from...... the jars, wood blocks were dried, analyzed for weight loss, ground into powder, and pressed into pellets.  Pellets were analyzed by x-ray diffraction using a ¿-2¿ scan and the resulting spectra were deconvoluted to determine average crystallite width and overall percent crystallinity. Results showed...

  10. Development of a Reproducible Powder Characterization Method using a Powder Rheometer

    DEFF Research Database (Denmark)

    Søgaard, Søren Vinter; Allesø, Morten; Garnæs, Jørgen

    2012-01-01

    In this study, a powder rheometer was used to measure flow characteristics of two pharmaceutical model powders. Precise measurements were obtained for one of the model powders whereas the results were less precise for the second powder. In conclusion, further work is needed to increase...... the mechanistic understanding of powder rheological measurements....

  11. Refraction and absorption of microwaves in wood

    International Nuclear Information System (INIS)

    Ziherl, Saša; Bajc, Jurij; Čepič, Mojca

    2013-01-01

    A demonstration experiment for physics students showing the dependence of the refractive index and absorption coefficient of wood on the direction of microwaves is presented. Wood and microwaves enable study of anisotropic properties, which are typically found in crystals. Wood is used as the persuasive representative of uniaxial anisotropic materials due to its visible structure and its consequent anisotropic properties. Wood can be cut in a general direction and wooden plates a few centimetres thick with well-defined fibre orientation are easily prepared. Microwaves are used because wood is transparent for microwaves and their centimetre-scale wavelength is comparable to the wood structure. (paper)

  12. wood burns down

    Directory of Open Access Journals (Sweden)

    Vladimir Bukh

    2004-11-01

    Full Text Available To relax the local authorities and to receive the guests of high rank «with no tie» the so-called «Fisherman's House» was built at the source of Angara-river, near Lake Baikal. Vladimir Ivanov, a young architect, was noticed by his skillful performa nee of exclusive orders and became the author of this house. At the time of ferroconcrete boom the proposal to build a wooden guest house turned out to be unexpectedly to the point and was graciously approved. The economic department was entrusted to select the men good for carpenter's work, and the forestry department was entrusted to provide thick round timber. And the work started. But, as it usually happens, the workers did not take the trouble and made the first eight rims of the current timber with an inappropriate diameter.And when Pavlov insisted on demolishing the construction and replacing the logs by the logs with the necessary diameter, the building work obeyed to his will and was finished suecessfully.The architecture of the house is not the derived action of the saw and the fret-saw. It is a technology of the axe. It is natural, convincing and original. It is no use to look for the local sources in it. It grew up in the area of timber and cold winter. And this clear and efficient action kept the construction from the annoying vulgarity and provided Siberian exotics easily penetrating into one's soul, refined as it may be.One of the eminent guests said with admiration: «Even if Pavlov had created nothing more, he would have justified his professional choice with this single house.» Why not to say it as a good toast. However, this is a suitable case to add: style is an absence of style. It is a taste.After the Fisherman's House Irkutsk architects were attracted by wood. They followed the strictness in wood and, as much as they could, created a couple of successful remakes, until the cylinder logs and ... new

  13. In line wood plastic composite pyrolyses and HZSM-5 conversion of the pyrolysis vapors

    International Nuclear Information System (INIS)

    Lin, Xiaona; Zhang, Zhijun; Tan, Shun; Wang, Fengqiang; Song, Yongming; Wang, Qingwen; Pittman, Charles U.

    2017-01-01

    Graphical abstract: HZSM-5 can be used to catalytic convert Wood Fiber-Polypropylene or Wood Fiber-Polypropylene pyrolysis vapors into aromatic compounds in reasonable selectivities. This provides a recycling utilization WPCs wastes method. - Highlights: • Converting wood/plastic composites (WPC) wastes into aromatics. • Recycling WPC by fast pyrolysis coupled with vapor catalytic cracking. • Selective production of aromatics from WPCs and their components over HZSM-5. • Acid site concentration inside zeolite was critical for maximizing aromatic yield. • Synergistic effects between wood and plastics enhanced aromatics production. - Abstract: Wood powder-high density polyethylene (WPE) and wood powder-polypropylene (WPP) composites were pyrolyzed at 550 °C in the presence of HZSM-5 catalysts using analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Immediately passing the pyrolysis vapors through the HZSM-5 changed the product distribution by producing aromatic hydrocarbons and eliminating tar formation. Zeolite HZSM-5 was employed with three different silica-to-alumina ratios (25, 50, 260). The influence of catalysts on the yields of aliphatic and aromatic hydrocarbons, furan derivatives, lignin-derived compounds and acetic acid was studied. High yields of aliphatic hydrocarbons formed in WPE or WPP pyrolysis alone. The highest yields of aromatic hydrocarbons from WPE or WPP pyrolysis vapors over HZSM-5 occurred with a zeolite framework Si/Al ratio of 25 (more acid sites), suggesting that the concentration of acid sites inside the zeolite was critical for maximizing aromatic yield. Exposing vapors to HZSM-5 increased the hydrocarbon yields and reduced the amount of acetic acid produced, resulting in increased calorific value. The yields of typical aromatics from catalytic pyrolysis of WPP mixture and composites were higher than those of the calculated values of poplar wood and PP catalytic pyrolysis individually, indicating that a

  14. Thermopower of beech wood biocarbon

    Science.gov (United States)

    Smirnov, I. A.; Smirnov, B. I.; Orlova, T. S.; Sulkovski, Cz.; Misiorek, H.; Jezowski, A.; Muha, J.

    2011-11-01

    This paper reports on measurements of the thermopower S of high-porosity samples of beech wood biocarbon with micron-sized sap pores aligned with the tree growth direction. The measurements have been performed in the temperature range 5-300 K. The samples have been fabricated by pyrolysis of beech wood in an argon flow at different carbonization temperatures ( T carb). The thermopower S has been measured both along and across the sap pores, thus offering a possibility of assessing its anisotropy. The curves S( T carb) have revealed a noticeable increase of S for T carb biocarbons, which suggests that for T carb ˜ 1000°C they undergo a phase transition of the insulator-(at T carb 1000°C) type. The existence of this transition is attested also by the character of the temperature dependences S( T) of beech wood biocarbon samples prepared at T carb above and below 1000°C.

  15. Assessment of the wood waste resource and its position in the wood / wood-energy sector - Synthesis

    International Nuclear Information System (INIS)

    Guinard, Ludovic; Deroubaix, Gerard; Roux, Marie-Lise; Levet, Anne-Laure; Quint, Vincent

    2015-04-01

    The first objective of this study is to obtain a better knowledge of the 'wood wastes' issue, to propose a photography of the wood waste sector (productions, trades, consumptions), and then to elaborate different prospective scenarios on the use of wood waste volumes while taking into account possible evolutions on the medium or short term of the regulation and market of the wood/wood energy sector. The considered wastes come from industrial production, from the use of wood-based products, and from the end of life of products potentially containing wood. The authors present bibliographical sources and the adopted methodology, briefly describe the 'wood waste' system with its actors, and then report their assessment of wood wastes. They propose a global assessment as well as detailed assessments with respect to waste origins: wood trade and distribution, industries, craft, households and communities, building sector, public and private tertiary sector, packaging. They also address the collection and management of wood wastes by public services, and present the different types of valorisation (panel fabrication, energy, and others). They discuss exports, and then present different scenarios: a trend-based scenario, and two prospective scenarios with a priority to energetic valorisation or to material valorisation of wood wastes. These scenarios are compared

  16. Wood: a construction material for tall buildings

    Science.gov (United States)

    Wimmers, Guido

    2017-12-01

    Wood has great potential as a building material, because it is strong and lightweight, environmentally friendly and can be used in prefabricated buildings. However, only changes in building codes will make wood competitive with steel and concrete.

  17. Ergonomics and safety in secondary wood processing

    Science.gov (United States)

    Rado Gazo; James D. McGlothlin; Yuehwern, Wiedenbeck, Jan Yih; Yuehwern Yih

    2002-01-01

    The main goal of the project was to initiate a pilot program in ergonomics for the secondary wood products industry. Case studies were conducted at three Midwest secondary wood product companies in 2000 and 2001.

  18. SYNERGISTIC WOOD PRESERVATIVES FOR REPLACEMENT OF CCA

    Science.gov (United States)

    The objective of this project was to evaluate the potential synergistic combinations of environmentally-safe biocides as wood preservatives. These wood preservatives could be potential replacements for the heavy-metal based CCA.Didecyldimethylammonium chloride [DDAC] was...

  19. Wood preservatives and pressure-treated wood: considerations for historic-preservation projects

    Science.gov (United States)

    Ronald W. Anthony; Stan T. Lebow

    2015-01-01

    Wood, an abundant resource throughout most of the world, has been used as a building material for thousands of years. Many historic buildings have been built primarily of wood, and masonry and stone buildings generally have wood elements, both structural and architectural. As a biological material, wood is both remarkably complex and yet quite durable if well...

  20. Effects of wood fiber characteristics on mechanical properties of wood/polypropylene composites

    Science.gov (United States)

    Nicole M. Stark; Robert E. Rowlands

    2003-01-01

    Commercial wood flour, the most common wood-derived filler for thermoplastics, is produced in a mixture of particle sizes and generally has a lower aspect ratio than wood and other natural fibers. To understand how wood flour and fiber characteristics influence the mechanical properties of polypropylene composites, we first investigated the effect of different sizes of...

  1. Durable protection of the surface of wood used outdoors: material constraints, problems and approaches to solutions

    Directory of Open Access Journals (Sweden)

    Merlin A.

    2018-01-01

    Full Text Available The aesthetic durability of wooden structures is a major challenge for the use of this material in construction. Wood is used for its technical performances but also for its architectural qualities and its aesthetic perception. The premature aging of the wooden structures is detrimental because these disorders, even if they do not affect the strength of the structures, are mostly irremediable. The surface protection of wood is generally ensured by the use of a finish, whose essential role is to protect wood from climatic aggressions (water, solar radiation, oxygen, .... The secondary wood processing industry consists of a series of manufacturing and processing activities, each containing a portion of the added value of the product. The application of a finish on a wood-based work is usually the last and most visible step in this value chain.In outdoor use, the protection of the wood surface with transparent finishes is not yet sufficiently durable to be able to compete with materials used in industrial carpentry such as PVC or aluminum. Opaque finishes generally provide more durable protection but they mask the appearance of the wood sought by users.With the aim of positioning wood in this construction sector, research on transparent finishes has focused on the efficiency and improvement of the durability of the protection of the surface appearance of structures. Faced with climatic aggressions, the optimum conservation of a structure is not only linked to the performance of the finish but also to the characteristics of the wood material. In particular, in order to fulfill its protective function, the finish film must be able to follow the dimensional variations of the wood it covers without breaking and without detachment. In addition to the criteria for the effectiveness of finishes in the protection of structures, the environmental impact must be considered with increasing attention. Currently, more than 80% of composite or solid wood

  2. Fuel wood symposium; Symposium Energieholz

    Energy Technology Data Exchange (ETDEWEB)

    Wild, C.; Wauer, A. (comps.)

    2001-07-01

    The Bavarian State Institute of Forestry (LWF) organised a 'Fuel Wood Symposium' in Freising-Weihenstephan on 17.11.2000. The purpose of this specialist conference was to give an overview of the use of biomass, especially wood, as an source of energy. (orig.) [German] Die Bayerische Landesanstalt fuer Wald und Forstwirtschaft richtete am 17.11.2000 in Freising-Weihenstephan das 'Symposium Energieholz' aus. Ziel der Fachtagung war es, einen Ueberblick ueber die energetische Nutzung von Biomasse, insbesondere Holz, zu geben. (orig.)

  3. Wood Properties and Kinds; A Base Syllabus on Wood Technology.

    Science.gov (United States)

    Eastern Kentucky Univ., Richmond.

    Prepared by participants in the 1968 National Defense Education Act Institute on Wood Technology, this syllabus is one of a series of basic outlines designed to aid college level industrial arts instructors in improving and broadening the scope and content of their programs. This booklet is concerned largely with the physical composition and…

  4. Bioremediation of treated wood with fungi

    Science.gov (United States)

    Barbara L. Illman; Vina W. Yang

    2006-01-01

    The authors have developed technologies for fungal bioremediation of waste wood treated with oilborne or metal-based preservatives. The technologies are based on specially formulated inoculum of wood-decay fungi, obtained through strain selection to obtain preservative-tolerant fungi. This waste management approach provides a product with reduced wood volume and the...

  5. Effects of phosphoramides on wood dimensional stability

    Science.gov (United States)

    Hong-Lin. Lee; George C. Chen; Roger M. Rowell

    2000-01-01

    To evaluate the dimensional stability of phosphoramide-reacted wood, wood was reacted with a mixture which was derived from compounding phosphorus pentoxide and each of 12 amines including alkyl, halophenyl, and phenyl amines in N,N-dimethylformamide. Dimensional stability of such reacted wood was analyzed by antishrink efficiency (ASE) using the water-soak method....

  6. Mapping wood production in European forests

    NARCIS (Netherlands)

    Verkerk, P.J.; Levers, C.; Kuemmerle, T.; Lindner, M.; Vanbuena, R.; Verburg, P.H.; Zudin, S.

    2015-01-01

    Wood production is an important forest use, impacting a range of other ecosystem services. However, information on the spatial patterns in wood production is limited and often available only for larger administrative units. In this study, we developed high-resolution wood production maps for

  7. Wood properties affecting finish service life

    Science.gov (United States)

    R. Sam. Williams; Charles. Jourdain; George I. Daisey; Robert W. Springate

    2000-01-01

    Wood is a biological material that has widely different properties depending on species, geographic area where the tree grew, the growth conditions, size of the tree at harvest, sawing, and other manufacturing processes. Some of the more important wood properties as they relate to wood finishing are discussed, e.g., growth rate, density, knots, extractives, juvenile...

  8. Build Green: Wood Can Last for Centuries

    Science.gov (United States)

    Carol A. Clausen; Samuel V. Glass

    2012-01-01

    This report updates and revises information from the 1976 Forest Service publication by Rodney C. DeGroot, “Your Wood Can Last for Centuries.” It explains why wood decays, alerts the homeowner to conditions that can result in decay in buildings, and describes measures to prevent moisture-related damage to wood.

  9. Characteristics and availability of commercially important woods

    Science.gov (United States)

    Regis B. Miller

    1999-01-01

    Throughout history, the unique characteristics and comparative abundance of wood have made it a natural material for homes and other structures, furniture, tools, vehicles, and decorative objects. Today, for the same reasons, wood is prized for a multitude of uses. All wood is composed of cellulose, lignin, hemicelluloses, and minor amounts (5% to 10%) of extraneous...

  10. European wood-pastures in transition

    DEFF Research Database (Denmark)

    Wood-pastures are important elements of European cultural identity and have an exceptional ecological value, yet they are in decline all over Europe. The structure of wood-pastures is strongly influenced by grazing and multiple other land uses and by local and regional environmental conditions. T...... conservation policies and management approaches for wood-pastures....

  11. Wood Flour Moulding Technology: Implications for Technical ...

    African Journals Online (AJOL)

    Wood Flour Moulding Technology: Implications for Technical Education in Nigeria. ... Interest in this modern industrial practice in wood anchors around the high level of unemployment among the youths in. Nigeria. ... flour moulding technology minimizes atmospheric pollution, reduces cost of wood waste disposal and curbs, ...

  12. The wood energy; Le bois energie

    Energy Technology Data Exchange (ETDEWEB)

    Vachey, C.

    2000-05-01

    This paper is a first approach of the wood energy. It presents the wood fuels, the automatic wood boilers for the collective buildings and the different domestic uses. An estimation of the cost and the advantages and disadvantages are also presented. (A.L.B.)

  13. Sustainable wood waste management in Nigeria

    Directory of Open Access Journals (Sweden)

    Owoyemi Jacob Mayowa

    2016-09-01

    Full Text Available Wood industries produce large volumes of residues which must be utilized, marketed or properly disposed of. Heaps of wood residues are common features in wood industries throughout the year. In Nigeria, this residue is generally regarded as waste and this has led to open burning practices, dumping in water bodies or dumping in an open area which constitutes environmental pollution. Sawmills in Nigeria generated over 1,000,000 m3 of wood waste in 2010 while about 5000 m3 of waste was generated in plywood mills. Nigeria generates about 1.8 million tons of sawdust annually and 5.2 million tons of wood wastes. The impact of improper disposal of waste wood on the environment affects both the aquatic and terrestrial ecosystems. Also burning of waste wood releases greenhouse gases into the atmosphere causing various health issues. Reuse/recycling of these wood residues in Nigeria will reduce the pressure on our ever decreasing forests, reduce environmental pollution, create wealth and employment. The literature available on this subject was reviewed and this article, therefore, focuses on the various methods of wood waste disposal and its utilization in Nigerian wood industries, the effects of wood waste on the environment as well as on human health and the benefits of proper wood waste management practices.

  14. Mechanical Behaviour of the Wood Masonry

    Directory of Open Access Journals (Sweden)

    Fazia FOUCHAL

    2011-09-01

    Full Text Available In this paper we study the walls wood masonry behaviour. First, we propose a regulatory validation of the walls wood masonry behaviour subjected to vertical and horizontal loads according to Eurocode 5. Then we present the numerical application on the wall wood supported two floors level.

  15. Determination of pectin content of eucalyptus wood

    NARCIS (Netherlands)

    Coetzee, B.; Schols, H.A.; Wolfaardt, F.

    2011-01-01

    Very little is known about the occurrence of pectin in wood and it is speculated that between 10 mg g-1 and 40 mg g-1 of wood consists of pectin. The present study aimed to quantify pectin in eucalyptus wood and to determine the influence of tree species, yield potential of the site, tree age class

  16. Cone calorimeter tests of wood composites

    Science.gov (United States)

    Robert H. White; Kuma Sumathipala

    2013-01-01

    The cone calorimeter is widely used for the determination of the heat release rate (HRR) of building products and other materials. As part of an effort to increase the availability of cone calorimeter data on wood products, the U.S. Forest Products Laboratory and the American Wood Council conducted this study on composite wood products in cooperation with the Composite...

  17. Mask materials for powder blasting

    NARCIS (Netherlands)

    Wensink, H.; Jansen, Henricus V.; Berenschot, Johan W.; Elwenspoek, Michael Curt

    Powder blasting, or abrasive jet machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials such as glass, silicon and ceramics. The particle jet (which

  18. Utilization of Wood Waste Mahang (Macaranga SP.) From Sawmill Industry for Making Wood Vinegar

    OpenAIRE

    Sutrisno, Lis; Sulaeman, Rudianda; Sribudiani, Evi

    2014-01-01

    Wood vinegar is the result of condensation and combustion products directly or indirectly. One of the methodes to make wood vinegar is by condensing the smoke products of incomplete combustion (pyrolysis). Materials used for the manufacture of wood vinegar is mahang wood waste from the sawmill industry in the form of sawdust, shavings and slashes. This study aims to determine how much rendement, chemical constituents of wood vinegar (phenol, total acid and pH) as well as the colors of the v...

  19. Advanced composites take a powder

    Energy Technology Data Exchange (ETDEWEB)

    Holty, D.W. (Custom Composite Materials, Inc., Atlanta, GA (United States))

    1993-06-01

    To a professional chemist with more than 25 years of industrial experience, the world of advanced composites is a fascinating new venue. Here resins and fibers come together in a completely synergistic partnership, achieving marvels of strength and light weight that make advanced composite materials virtually the only solution for challenging applications. In the late 1980s, Professor John Muzzy of the Georgia Institute of Technology, was intrigued by the physical properties of thermoplastics, and he developed a new way to bring the thermoplastic resins together with high-performance fibers. As part of the work Muzzy did with Lockheed and NASA he demonstrated that electrostatic powder coating was an attractive new method for combining thermoplastic resins with reinforcing fibers. Presentation of this work by Lockheed at a government-industry conference led to a new project for Muzzy, sponsored by NASA Langley. Powder prepregging proved to be the attractive alternative that NASA was looking for. While working on powder prepregging with LaRC-TPI, Muzzy and his colleagues developed methods for exposing all of the fibers to the powder to improve the distribution of the resin on the tow, a continuous bundle of filaments. Optimal resin distribution was achieved by spreading the moving tow. A very flexible towpreg was produced by maintaining the spread tow through the powder coating chamber and into the oven, where the resin particles were fused to the individual filaments. Muzzy's invention has enabled Custom Composite Materials, Inc. to offer resin/fiber combinations based on thermoplastic resins such as nylon and polypropylene. Beyond the expected advantages over epoxy thermoset systems, they are beginning to exploit a fundamental property of thermoplastic resins: viscoelasticity, which can be defined as the resistance to flow as a function of applied stress. Thermoplastics have a much higher viscoelasticity than thermosets.

  20. Body of Wood

    Directory of Open Access Journals (Sweden)

    Pierre Michon

    2014-12-01

    not only a defrocked friar with the guys or on the street; he donned the silk babouches when he went home too. He dispossessed himself of the Seine that rolled on before his eyes; the small girl who lived on her feet, whom he puts to death in all his books, he hardly saw her; the loveliest girls of his day, the finest too for sure, who wanted him, so that he happened to come – he dispossessed himself of them, whether he came or opted to come no more, which amounted to the same thing; no apples from Norman orchards, no trees deep in the woods, no unlaced Louise Colet, no lilies, no young laughter, no Louise Colet weeping at his door, he kissed it all off, laughed over it and kissed it off, cried about it and kissed it off, he was not there. In fact he had nothing, he was deprived of everything, since it was in his head.

  1. Nanoindentation size effects in wood

    Science.gov (United States)

    Joseph E. Jakes; Donald S. Stone; Charles R. Frihart

    2007-01-01

    The purpose of this work was to test some of the assumptions underlying methods currently employed to investigate nanoindentation properties of wood. We examined whether hardness and modulus depend on load. We employed a surface preparation technique that minimizes alterations of cell wall properties. Areas were determined using both (a) Oliver-Pharr method and (b) a...

  2. Adhesive bonding of wood materials

    Science.gov (United States)

    Charles B. Vick

    1999-01-01

    Adhesive bonding of wood components has played an essential role in the development and growth of the forest products industry and has been a key factor in the efficient utilization of our timber resource. The largest use of adhesives is in the construction industry. By far, the largest amounts of adhesives are used to manufacture building materials, such as plywood,...

  3. The Hygroscopic Nature of Wood,

    Science.gov (United States)

    The cell walls of wood are organized as a structural system involving filamentous microfibrils , oriented essentially in the direction of the...longitudinal axis embedded in an amorphous matrix of noncrystalline cellulose , hemicelluloses, and lignin. The molecules in the amorphous regions, primarily

  4. China: changing wood products markets

    Science.gov (United States)

    Daowei Zhang; Junchang Liu; James Granskog; Jianbang Gan

    1998-01-01

    In the 1980's, China emerged as the world's second largest importer of forest products and the second largest importer of U.S. forest products. However, U.S. wood products exports to China declined nearly 93 percent from 1988 to 1996, from >/=448 million to >/=33 million. Little is known about the reasons that caused this decline. Less is probably known...

  5. Wood and concrete polymer composites

    International Nuclear Information System (INIS)

    Singer, K.

    1974-01-01

    There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

  6. Kinetic investigation of wood pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Thurner, F.; Mann, U.; Beck, S. R.

    1980-06-01

    The objective of this investigation was to determine the kinetics of the primary reactions of wood pyrolysis. A new experimental method was developed which enabled us to measure the rate of gas, tar, and char production while taking into account the temperature variations during the wood heating up. The experimental method developed did not require any sophisticated instruments. It facilitated the collection of gas, tar and residue (unreacted wood and char) as well as accurate measurement of the temperature inside the wood sample. Expressions relating the kinetic parameters to the measured variables were derived. The pyrolysis kinetics was investigated in the range of 300 to 400/sup 0/C at atmospheric pressure and under nitrogen atmosphere. Reaction temperature and mass fractions of gas, tar, and residue were measured as a function of time. Assuming first-order reactions, the kinetic parameters were determined using differential method. The measured activation energies of wood pyrolysis to gas, tar, and char were 88.6, 112.7, and 106.5 kJ/mole, respectively. These kinetic data were then used to predict the yield of the various pyrolysis products. It was found that the best prediction was obtained when an integral-mean temperature obtained from the temperature-time curve was used as reaction temperature. The pyrolysis products were analyzed to investigate the influence of the pyrolysis conditions on the composition. The gas consisted mainly of carbon dioxide, carbon monoxide, oxygen, and C/sub 3//sup +/-compounds. The gas composition depended on reaction time as well as reactor temperature. The tar analysis indicated that the tar consisted of about seven compounds. Its major compound was believed to be levoglucosan. Elemental analysis for the char showed that the carbon content increased with increasing temperature.

  7. Characteristics and Manufacture of Spherical Smokeless Powders

    OpenAIRE

    Botelho, Fernanda Diniz; Galante, Erick Braga Ferrão; Mendes, Álvaro José Boareto

    2015-01-01

    ABSTRACT: Smokeless propellants have been studied and manufactured for many decades. They can exist in various physical forms and also can have different properties according to the use of each propellant. One important form of smokeless powders is the ball powder, which has spherical grains. The manufacture process of the ball powder has many advantages over the usual way to manufacture a smokeless powder. For example, unstable and even deteriorated nitrocellulose, after being stabilized aga...

  8. Upgraded wood residue fuels 1995; Foeraedlade traedbraenslen 1995

    Energy Technology Data Exchange (ETDEWEB)

    Vinterbaeck, J. [Swedish Univ. of Agricultural Science, Uppsala (Sweden). Dept. of Forest-Industry-Market Studies

    1995-11-01

    The Swedish market for upgraded residue fuels, i.e. briquettes, pellets and wood powder, has developed considerably during the nineties. The additional costs for the upgrading processes are regained and create a surplus in other parts of the system, e.g. in the form of higher combustion efficiencies, lower investment costs for burning equipment, lower operation costs and a diminished environmental impact. All these factors put together have resulted in a rapid growth of this part of the energy sector. In 1994 the production was 1.9 TWh, an increase of 37 % compared to the previous year. In the forthcoming heating season 1995/96 the production may reach 4 TWh. 57 refs, 11 figs, 6 tabs

  9. Wood pellets : a worldwide fuel commodity

    International Nuclear Information System (INIS)

    Melin, S.

    2005-01-01

    Aspects of the wood pellet industry were discussed in this PowerPoint presentation. Details of wood pellets specifications were presented, and the wood pellet manufacturing process was outlined. An overview of research and development activities for wood pellets was presented, and issues concerning quality control were discussed. A chart of the effective calorific value of various fuels was provided. Data for wood pellet mill production in Canada, the United States and the European Union were provided, and various markets for Canadian wood pellets were evaluated. Residential sales as well as Canadian overseas exports were reviewed. Production revenues for British Columbia and Alberta were provided. Wood pellet heat and electricity production were discussed with reference to prefabricated boilers, stoves and fireplaces. Consumption rates, greenhouse gas (GHG) emissions, and fuel ratios for wood pellets and fossil fuels were compared. Price regulating policies for electricity and fossil fuels have prevented the domestic expansion of the wood pellet industry. There are currently no incentives for advanced biomass combustion to enter British Columbia markets, and this has led to the export of wood pellets. It was concluded that climate change mitigation policies will be a driving force behind market expansion for wood pellets. tabs., figs

  10. Solidification and Microstructural Characterization on Atomized Powders

    Directory of Open Access Journals (Sweden)

    Şadi KARAGÖZ

    2009-03-01

    Full Text Available Powders produced by atomization techniques are commonly used in many industrial applications due to their many advantages such as homogeneous microstructure, low contamination and production of desired size range. In this study, the solidification of some ferrous and non-ferrous based alloy powders were considered and microstrucural characterization of all powder was carried out.

  11. 21 CFR 73.2645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements of...

  12. 21 CFR 73.1645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum. It...

  13. Natural radionuclides and radiocaesium contained in wood

    International Nuclear Information System (INIS)

    Mahmoud, Kamal Reyad; El-Husseiny, Fathy Ahmed; Badran, Hussein Mahmoud

    2004-01-01

    The activity concentrations of natural ( 226 Ra, 232 Th and 40 K) and anthropogenic ( 137 Cs) radioactive elements in local and imported wood samples have been investigated during the last few years. Seven local and four imported wood types were measured. The activities of the natural isotopes in both local and imported wood samples were comparable. The Chernobyl accident didn't only affect European countries through contamination of the forested but also non-wood producing countries like Egypt. A fraction of the deposited fallout radionuclides has become incorporated into wood. Most of the imported samples (∼ 83%) showed measurable concentration of 137 Cs. The average 137 Cs activity levels in local and imported wood were 0.16 and 2.75 Bq/kg dry weight, respectively. The result of this study has its importance to many other wood-importing countries. (author)

  14. Mathematical Simulation of Temperature Profiles within Microwave Heated Wood Made for Wood-Based Nano composites

    International Nuclear Information System (INIS)

    Li, X.; He, X.; Lv, J.; Wu, Y.; Luo, Y.; Chen, H.

    2013-01-01

    High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nano composites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased along the direction of microwave transmission when the unilateral microwave heating was applied, and the temperature difference along the thickness direction of wood was very significant; The temperature with wood firstly increased and then gradually decreased from the wood surface to interior when the bilateral microwave heating was applied. Compared with the unilateral microwave heating, bilateral microwave heating is a better microwave heating method for the more uniform wood microwave pretreatment.

  15. [Impact of directly compressed auxiliary materials on powder property of fermented cordyceps powder].

    Science.gov (United States)

    Chen, Li-Hua; Yue, Guo-Chao; Guan, Yong-Mei; Yang, Ming; Zhu, Wei-Feng

    2014-01-01

    To investigate such physical indexes as hygroscopicity, angle of repose, bulk density, fillibility of compression of mixed powder of directly compressed auxiliary materials and fermented cordyceps powder by using micromeritic study methods. The results showed that spray-dried lactose Flowlac100 and microcrystalline cellulose Avicel PH102 had better effect in liquidity and compressibility on fermented cordyceps powder than pregelatinized starch. The study on the impact of directly compressed auxiliary materials on the powder property of fermented cordyceps powder had guiding significant to the research of fermented cordyceps powder tablets, and could provide basis for the development of fermented cordyceps powder tablets.

  16. Polycapillary optics for powder diffraction

    Science.gov (United States)

    Huang, Huapeng; MacDonald, Carolyn A.; Gibson, Walter M.; Chik, John; Parsegian, Adrian; Ponomarev, Igor Y.

    2001-12-01

    In this paper, we describe a low power system using Polycapillary collimating and focusing optics that were designed to collect Cu Ka radiation from an Oxford Ultra-Bright micro-focus source for X-ray powder diffraction measurements. The characterizations of the source and polycapillary optics are presented. A collimator with two apertures was used to block high energy X-rays. An optic alignment system was designed to optimize coupling between the optics and the source, taking into account the maximum radiation direction from the source. Several powder sample data sets were collected with this system and their qualities are compared with data sets from the same samples taken with an Enraf-Nonius FR590 sealed-tube source system. Discussion is also presented for further improving the performance of this low power system.

  17. Powder Diffraction in Zeolite Science

    Science.gov (United States)

    Burton, Allen W.

    This tutorial discusses the fundamental principles of X-ray diffraction and its applications in zeolite science. The early sections review the physics of diffraction, crystal symmetry, and reciprocal space. We discuss how the intensity of diffracted radiation is affected both by geometric effects involving detection (the Lorentz-polarization factor) and by the arrangement of atoms within the crystal (the structure factor). The differences between powder diffraction and single-crystal diffraction are then described, and differences between X-ray and neutron diffraction are also discussed. Later sections describe the effects of symmetry, lattice substitution, crystallite size, residual strain, preferred orientation, and X-ray absorption. Special emphasis is placed on the proper application of the Scherrer analysis in reporting crystalize size. The principles of structure solution from direct methods and Patterson methods are then introduced, and a description of Rietveld analysis is given. Finally the effects of stacking disorder on a powder diffraction pattern are presented.

  18. Cryogenic Milling of Titanium Powder

    Directory of Open Access Journals (Sweden)

    Jiří Kozlík

    2018-01-01

    Full Text Available Ti Grade 2 was prepared by cryogenic attritor milling in liquid nitrogen and liquid argon. Two types of milling balls were used—stainless steel balls and heavy tungsten carbide balls. The effect of processing parameters on particle size and morphology, contamination of powder and its microhardness was investigated. Milling in liquid nitrogen was not feasible due to excessive contamination by nitrogen. Minor reduction of particle size and significant alterations in particle morphology depended on type of milling balls and application of stearic acid as processing control agent. Heavily deformed ultra-fine grained (UFG internal microstructure of powder particles was observed by the method of “transmission Kikuchi diffraction”.

  19. Manufacture of uranium dioxide powder

    International Nuclear Information System (INIS)

    Becker, M.

    1976-01-01

    Uranium dioxide powder is prepared by the AUC (ammonium uranyl carbonate) method. Supplementing the known process steps, the AUC, after separation from the mother liquor, is washed with an ammonium hydrogen carbonate or an NH 4 OH solution and is subsequently post-treated with a liquid which reduces the surface tension of the residual water in an AUC. Such a liquid is, for instance, alcohol

  20. Terahertz dielectric measurements of household powders

    Science.gov (United States)

    Khan, Usman A.; Afsar, Mohammed N.

    2007-09-01

    The dielectric properties of common household powders from 0.6 to 1.2 THz are presented in this paper. Terahertz Dispersive Fourier Transform Spectroscopy was used to yield the dielectric properties of powders as a continuous function of frequency. Tests were conducted using a polarized interferometer and two cryogenically-cooled high frequency detectors. Dielectric spectroscopy was utilized to provide high-resolution and precise information on the dielectric spectra of powders including the powder's unique resonance signature. This signature can be employed to detect the presence of a hoax or harmful powder within a baggage or mail package.

  1. [Advances in studies on bear bile powder].

    Science.gov (United States)

    Zhou, Chao-fan; Gao, Guo-jian; Liu, Ying

    2015-04-01

    In this paper, a detailed analysis was made on relevant literatures about bear bile powder in terms of chemical component, pharmacological effect and clinical efficacy, indicating bear bile powder's significant pharmacological effects and clinical application in treating various diseases. Due to the complex composition, bear bile powder is relatively toxic. Therefore, efforts shall be made to study bear bile powder's pharmacological effects, clinical application, chemical composition and toxic side-effects, with the aim to provide a scientific basis for widespread reasonable clinical application of bear bile powder.

  2. Dynamic compaction of ceramic powders

    Energy Technology Data Exchange (ETDEWEB)

    Cline, C.F.

    1982-06-10

    Dynamic consolidation is a technique for densifying powder ensembles to near theoretical with or without external application of heat. The technique itself is simple: the confined powder, initially at a green density of approx. 50% encounters a high pressure shock wave which exceeds the yield strength and densifies as the wave proceeds through the compact. The time scales and pressure range from 1-10's of microseconds and 10-100's of kilobars (10 Kb = 1 GPa). The short time scale of the pressure pulse during the compaction stage inhibits kinetic processes which have longer time constants. The pressure pulse can be delivered to the green compact by a number of techniques, i.e. high explosive, projectile. The methods differ in the degree that one can control the amplitude, duration, and nature of the pressure pulse. The lecture compares powders compacted by explosive and light gas guns and when possible characterize their resulting structures and properties, using AlN as example. 14 figures.

  3. Evaluation of a Regression Prediction Model for Surface Roughness of Wood-Polyethylene Composite (wpc)

    Science.gov (United States)

    Shi, Wenyong; Ma, Yan; Yang, Chunmei; Jiang, Bin; Li, Zhe

    Milling processing is an important way to obtain wood-polyethylene composite (WPC) end products. In order to improve the processing efficiency and surface quality of WPC and meet the practical application requirements, this paper focussed on morphology and roughness of the WPC-milled surface and studied surface quality changes under different cutting parameters and milling methods through multi-parameters milling experiments. The milling surface morphology and roughness of WPC were analyzed and measured during cut-in, cutting and cut-out sections. It also revealed the affect rule of different cutting parameters and milling methods on milled surface morphology and roughness. The results show that the milling surface roughness of WPC products with wood powder content of 70% is significantly larger than the one whose wood powder content is 60%, and defects such as holes are also relatively more. Finally, a surface roughness prediction model was established based on the mathematical regression method and its multi-factor simulation was carried out. A comparative analysis of predictive and experimental values was performed to verify the reliability of the model. It could also provide theoretical guidance and technical guarantee for high processing quality of WPC milling and cutting.

  4. WOOD BIOMASS FOR ENERGY IN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Gradimir Danon

    2010-01-01

    Full Text Available Wood biomass has got its place in the energy balance of Montenegro. A little more than 6% of the total energy consumption is obtained by burning wood. Along with the appropriate state measures, it is economically and environmentally justified to expect Montenegro to more than double the utilization of the existing renewable energy sources including wood biomass, in the near future. For the purpose of achieving this goal, ‘Commercial Utilisation of the Wood Residue as a Resource for Economic Development in the North of Montenegro' project was carried out in 2007. The results of this project were included in the plan of the necessary interventions of the Government and its Agencies, associations or clusters, non-government organisations and interested enterprises. The plan was made on the basis of the wood residue at disposal and the attitude of individual subjects to produce and/or use solid bio-fuels and consists of a proposal of collection and utilisation of the wood residue for each individual district in the north of Montenegro. The basic factors of sustainability of future commercialisation of the wood residue were: availability of the wood raw material, and thereby the wood residue; the development of wood-based fuel markets, and the size of the profit.

  5. Wood energy and air quality

    International Nuclear Information System (INIS)

    2015-12-01

    This publication first recalls the main benefits of the use of wood, the first source of renewable energy in France: abundant and local resource, low CO 2 emission, competitiveness, job creation. It comments the relationship between the use of this source of energy and the compliance with air quality standards as they are notably defined by European directives, as the use of wood as heating source is one of the recommended lever to improve air quality. The publication comments emissions generated by this type of heating (mainly in the housing sector, with some critical meteorological periods). Levers for actions are discussed: fleet renewal to promote the best performing equipment, practice improvements (fuel quality, apparatus maintenance). Actions undertaken by the ADEME are briefly reviewed: support to individual equipment fleet modernisation, support to R and D, support to the sector, and information and communication

  6. Wood construction under cold climate

    DEFF Research Database (Denmark)

    Wang, Xiaodong; Hagman, Olle; Sundqvist, Bror

    2014-01-01

    was sensitive to temperature change. MUF, PRF and PVAc resins demonstrated different characters with Norway spruce and Scot pine. At room temperature, all types of adhesive showed relative stability, in terms of shear strength variation. While at low temperature, the shear strength varied considerably. More......) and Scots pine (Pinus sylvestris) joints (150mm x 20mm x 10mm) were bonded with seven commercially available resins (PUR, PVAc, EPI, MF, MUF1, PRF and MUF2) and tested at six temperatures (20, -20, -30, -40, -50 and -60 °C), respectively. Generally, for both species, temperature changes significantly...... affected shear strength of wood joints. As temperature decreased, the shear strength decreased. PUR resin resulted in the strongest shear strength at all temperatures tested. MF resin responded to temperature changes in a similar ways as the PUR resin. The shear strength of wood joints with EPI resins...

  7. Discover the benefits of residential wood heating

    International Nuclear Information System (INIS)

    2003-01-01

    This publication described how residential wood-heating systems are being used to reduce energy costs and increase home comfort. Biomass energy refers to all forms are renewable energy that is derived from plant materials. The source of fuel may include sawmills, woodworking shops, forest operations and farms. The combustion of biomass is also considered to be carbon dioxide neutral, and is not considered to be a major producer of greenhouse gases (GHG) linked to global climate change. Wood burning does, however, release air pollutants, particularly if they are incompletely burned. Incomplete combustion of wood results in dense smoke consisting of toxic gases. Natural Resources Canada helped create new safety standards and the development of the Wood Energy Technical Training Program to ensure that all types of wood-burning appliances are installed correctly and safely to reduce the risk of fire and for effective wood heating. In Canada, more than 3 million families heat with wood as a primary or secondary heating source in homes and cottages. Wood heating offers security from energy price fluctuations and electrical power failures. This paper described the benefits of fireplace inserts that can transform old fireplaces into modern heating systems. It also demonstrated how an add-on wood furnace can be installed next to oil furnaces to convert an oil-only heating system to a wood-oil combination system, thereby saving thousands of dollars in heating costs. Wood pellet stoves are another wood burning option. The fuel for the stoves is produced from dried, finely ground wood waste that is compressed into hard pellets that are loaded into a hopper. The stove can run automatically for up to 24 hours. New high-efficiency advanced fireplaces also offer an alternative heating system that can reduce heating costs while preserving Canada's limited supply of fossil fuels such as oil and gas. 13 figs

  8. North America's wood pellet sector

    Science.gov (United States)

    Henry Spelter; Daniel Toth

    2009-01-01

    The North American wood pellet sector is profiled in this paper. A small pellet industry has existed since the 1930s, but its main growth occurred in the wake of the energy crisis in the 1970s. Its current spurt is even greater, growing from is set to reach 6.2 million in 2009. Most plants are small, relying on sawmill residues for fiber and thus are limited to 100,000...

  9. Carbon Sequestration via Wood Burial

    Science.gov (United States)

    Zeng, N.

    2007-12-01

    To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which forest dead wood or old trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It was estimated that the carbon sequestration potential of forest wood harvest and burial is 10GtC y-1 with an uncertainty range of 5-15 GtC y-1. Based on data from North American logging industry, the cost was crudely estimated at $50/tC, significantly lower than the cost for power plant CO2 capture with geological storage, a carbon sequestration technique currently under most serious consideration. The low cost is largely because the CO2 capture is achieved at little cost by the natural process of photosynthesis. The technique is low tech, distributed, safe and can be stopped or reversed at any time. The relatively low cost may soon be competitive enough for large-scale implementation in a world-wide carbon trading market. In tropical regions with ongoing deforestation, wood burial instead of burning will immediately reduce that portion of the anthropogenic CO2 emission.

  10. Blood parasites of wood ducks

    Science.gov (United States)

    Herman, C.M.; Knisley, J.O.; Knipling, G.D.

    1971-01-01

    Examination of blood films from wood ducks (Aix sponsa) from several northeastern states revealed Haemoproteus, Leucocytozoon, Plasmodium and a typanosome. Haemoproteus occurred in all areas sampled and birds of the year from Massachusetts demonstrated the highest incidence during the last 2 weeks in August. Leucocytozoon was most prevalent in more northern areas. P. circumflexum and a trypanosome are reported for the first time from this host.

  11. Status of Wood Processing and Storage in Nigeria | Ohagwu ...

    African Journals Online (AJOL)

    The work showcases wood processing and storage operations in Nigeria. The importance of wood as a multipurpose biomaterial were discussed as well as its nature, characteristics, lumbering pattern and other product derived from wood. The available wood/timber in Nigeria as well as the unit operations in wood ...

  12. Chapter 02: Basic wood biology—Anatomy for identification

    Science.gov (United States)

    Alex Wiedenhoeft

    2011-01-01

    Before the topics of using a hand lens, preparing wood for observation, and understanding the characters used in wood identification can be tackled, a general introduction to the biology of wood must be undertaken. The woods in commercial trade in Central America come almost exclusively from trees, so the discussion of wood biology is restricted to trees here, though...

  13. Mechanical properties of small-scale wood laminated composite poles

    Science.gov (United States)

    Cheng Piao; Todd F. Shupe; Chung Y. Hse

    2004-01-01

    Power companies in the United States consume millions of solid wood poles every year. These poles are from high-valued trees that are becoming more expensive and less available. wood laminated composite poles (LCP) are a novel alternative to solid wood poles. LCP consists of trapezoid wood strips that are bonded by a synthetic resin. The wood strips can be made from...

  14. Carbon sequestration via wood burial

    Directory of Open Access Journals (Sweden)

    Zeng Ning

    2008-01-01

    Full Text Available Abstract To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1, followed by temperate (3.7 GtC y-1 and boreal forests (2.1 GtC y-1. Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC, lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.

  15. Power and efficiency of wood burning furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, D.; Froment, G.; Kubala, J.F.; Chantret, A.; Renault, G.

    1982-06-01

    In 1981 an automated test rig for wood boilers was set up at the COSTIC. The special characteristics of wood combustion made it necessary to develop a computerized measuring method that enables the progress of this combustion to be followed step by step in the furnaces. After a number of preliminary adjustments, it is possible to move on to a series of tests during which the essential difficulty is to assess the wood consumption.

  16. Wood Energy Potential in Northwestern South Carolina

    Science.gov (United States)

    James W. McMinn

    1986-01-01

    The quantity of unused wood in an Ill-county area in northwestern South Carolina was projected to be more than 16 million tons annually. Wood that is unsuitable for products other than fuel amounts to nearly 9 million tons annually.The most likely energy demand by industrial plants that are good candidates for wood fuel systems is 1.5 million tons annually.Maximum...

  17. Wood's light in Microsporum canis positive patients.

    Science.gov (United States)

    Kefalidou, S; Odia, S; Gruseck, E; Schmidt, T; Ring, J; Abeck, D

    1997-12-01

    In 64 patients with culturally proven Microsporum canis infections, Wood's light examination was performed. In 30 patients (47%) the characteristic fluorescence correlated with the cultural findings, whereas in the remaining 34 patients (53%), Microsporum canis was isolated, although Wood's light examination was negative. Of the 30 positive and 34 negative cases eight patients of each group had been pre-treated. From the results presented, Wood's light examination has a poor sensitivity in cases of Microsporum canis-infections.

  18. Study of wood polymer combinations for various woods of Kashmir - Part I

    International Nuclear Information System (INIS)

    Mohan, H.; Rao, K.N.

    1977-01-01

    The report describes the studies conducted to upgrade inferior woods in Kashmir by the method of radiation polymerisation. The normal qualities of wood are retained and modifications brought about in unfavourable properties such as softness, dimensional instability, hygroscopicity and compressibility. Various changes in properties of wood after the modifications are discussed. It is shown that 50% of polymer content in wood considerably improves the physical and mechanical properties. (author)

  19. The use of new, aqueous chemical wood modifications to improve the durability of wood-plastic composites

    Science.gov (United States)

    Rebecca E. Ibach; Craig M. Clemons; George C. Chen

    2017-01-01

    The wood flour used in wood-plastic composites (WPCs) can biologically deteriorate and thus the overall mechanical performance of WPCs decrease when exposed to moisture and fungal decay. Protecting the wood flour by chemical modification can improve the durability of the wood in a nontoxic way so it is not harmful to the environment. WPCs were made with modified wood...

  20. PIXE analysis of powdered milk

    International Nuclear Information System (INIS)

    Hallak, A.B.

    1983-01-01

    An accelerator-based study, using proton-induced x-ray emission (PIXE) was performed on four full-cream and four half-cream brands of powdered milk commonly consumed in Jordan. The elements detected in the samples are S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. The significance of some of these elements is discussed from the viewpoint of nutrition and also their effect on milk processing and dairy technology. The standard reference milk sample, A-11, which is distributed by IAEA was also examined, and the results for trace elements detected are compared with the values certified by IAEA. (author)

  1. Wood-energy in Europe: resources, technologies

    International Nuclear Information System (INIS)

    Defaye, S.

    1999-01-01

    A voluntaristic policy for the development of wood fuel would contribute to save energy and to protect the environment. Different strategies of development exist at the European scale as demonstrated by a recent report ordered by the French agency of environment and energy mastery (ADEME). This paper gives a synthesis of this report. It deals successively with: the European wood resources (the northern and continental forests, the mountain and bocage regions, the Mediterranean forests); the 3 main resources: forest exploitation, wood transformation, recycling of waste wood; the different economical status of wood resources; the place of wood-fuel in the economy: estimation, complementarity of industrial and energy uses; technological files and perspectives of development: collection, transport, conditioning, fuel production and supply, technologies of energy production from wood (domestic heating, collective heating, cogeneration and mixed wood-coal combustion); future markets; strategy of development: forestry and agriculture, management, producers, environmental aspects, afforestation of abandoned lands, employment...; policies of European, national and regional authorities: political and financial help, regulations and standardizations, financial helps and fiscal policy, inter-region cooperation and R and D, advice and communication; contribution of wood-fuel to the energy supply of Europe. (J.S.)

  2. Wood energy 2000; Bois energie 2000

    Energy Technology Data Exchange (ETDEWEB)

    Druette, L. [Centre Scientifique et Technique du Batiment, (CSTB), 44 - Nantes (France); Lacome, T. [AFNOR, 75 - Paris (France); Roy, C. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France)] [and others

    2000-07-01

    The deregulation of the Electric Market and the opening of the Green Certificate exchange market force the set up of renewable energies. The wood, which is for most of european countries an important part of renewable fuel, should see the increase of its utilization. This conference on the wood energy deals the main aspects of this energy development. The papers present the wood burning furnaces technology assessment, the wood fuel market and the standardization of the appliances in this domain. Some papers also include the consequences of the big storms of december 1999. (A.L.B.)

  3. The effect of wood extractives on the thermal stability of different wood species

    Energy Technology Data Exchange (ETDEWEB)

    Shebani, A.N.; Reenen, A.J. van [Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa); Meincken, M. [Department of Forest and Wood Science, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa)], E-mail: mmein@sun.ac.za

    2008-05-30

    This study compares the thermal stability of different wood species, which is an important factor for the production of wood-polymer composites (WPCs), and investigates the effect of extraction on thermal properties. The chemical composition of four wood species -Quercus alba, Pinus radiata, Eucalyptus grandis and Acacia cyclops - has been determined, as the species is expected to affect the thermal stability of wood. Subsequently, the hot-water (HW) extractives, ethanol/cyclohexane (E/C) extractives and both extractives were eliminated from the wood via Soxhlet extraction and the thermal stability of the wood determined with thermogravimetric analysis (TGA) under identical conditions. The results suggest that a higher cellulose and lignin content leads to better thermal stability of wood in different temperature regimes. In all cases, the removal of extractives improved the thermal stability of the wood. The effect of combined extractions was more pronounced than of an individual extraction and E/C-extraction caused less improvement in the thermal stability of wood than HW extraction. The degradation of the investigated wood extractives occurred at low rates over a broad temperature range. Pure cellulose exhibited superior thermal stability compared to wood, but differences were observed between the investigated wood species.

  4. Energy wood. Part 2b: Wood pellets and pellet space-heating systems

    International Nuclear Information System (INIS)

    Nussbaumer, T.

    2002-01-01

    The paper gives an overview on pellet utilization including all relevant process steps: Potential and properties of saw dust as raw material, pellet production with drying and pelletizing, standardization of wood pellets, storage and handling of pellets, combustion of wood pellets in stoves and boilers and applications for residential heating. In comparison to other wood fuels, wood pellets show several advantages: Low water content and high heating value, high energy density, and homogeneous properties thus enabling stationary combustion conditions. However, quality control is needed to ensure constant properties of the pellets and to avoid the utilization of contaminated raw materials for the pellet production. Typical data of efficiencies and emissions of pellet stoves and boilers are given and a life cycle analysis (LCA) of wood pellets in comparison to log wood and wood chips is described. The LCA shows that wood pellets are advantageous thanks to relatively low emissions. Hence, the utilization of wood pellet is proposed as a complementary technology to the combustion of wood chips and log wood. Finally, typical fuel cost of wood pellets in Switzerland are given and compared with light fuel oil. (author)

  5. Detection of wood failure by image processing method: influence of algorithm, adhesive and wood species

    Science.gov (United States)

    Lanying Lin; Sheng He; Feng Fu; Xiping Wang

    2015-01-01

    Wood failure percentage (WFP) is an important index for evaluating the bond strength of plywood. Currently, the method used for detecting WFP is visual inspection, which lacks efficiency. In order to improve it, image processing methods are applied to wood failure detection. The present study used thresholding and K-means clustering algorithms in wood failure detection...

  6. The central role of wood biology in understanding the durability of wood-coating interactions

    Science.gov (United States)

    Alex C. Wiedenhoeft

    2007-01-01

    To design effectively for durability, one must actively and honestly assess the material properties and limitations of each of the components in the design system; wood or wood composite, and the coating. Inasmuch as wood coatings are manufactured to specified tolerances from known materials, we have control of that component of the system. Compared to manmade...

  7. Moisture Performance of wood-plastic composites reinforced with extracted and delignified wood flour

    Science.gov (United States)

    Yao Chen; Nicole M. Stark; Mandla A. Tshabalala; Jianmin Gao; Yongming Fan

    2014-01-01

    This study investigated the effect of using extracted and delignified wood flour on water sorption properties of wood–plastic composites. Wood flour (WF) extraction was performed with three solvent systems: toluene/ethanol (TE), acetone/water (AW), and hot water (HW); delignification was conducted using sodium chlorite/acetic acid solution. A 24 full-factorial...

  8. Weathering characteristics of wood plastic composites reinforced with extracted or delignified wood flour

    Science.gov (United States)

    Yao Chen; Nicole M. Stark; Mandla A. Tshabalala; Jianmin Gao; Yongming Fan

    2016-01-01

    This study investigated weathering performance of an HDPE wood plastic composite reinforced with extracted or delignified wood flour (WF). The wood flour was pre-extracted with three different solvents, toluene/ethanol (TE), acetone/water (AW), and hot water (HW), or sodium chlorite/acetic acid. The spectral properties of the composites before and after artificial...

  9. Role of carbon source in the shift from oxidative to hydrolytic wood decomposition by Postia placenta.

    Science.gov (United States)

    Zhang, Jiwei; Schilling, Jonathan S

    2017-09-01

    Brown rot fungi initiate wood decay using oxidative pretreatments to improve access for cellulolytic enzymes. These pretreatments are incompatible with enzymes, and we recently showed that Postia placenta overcomes this issue by delaying glycoside hydrolase (GH) gene upregulation briefly (wood wafers and spatially mapped expression (via quantitative PCR) of twelve ORs and GHs targeted using functional genomics analyses. By layering expression patterns over solubilized sugar data (via HPLC) from wood, we observed solubilization of wood glucose, cellobiose, mannose, and xylose coincident with the OR-GH transition. We then tested effects of these soluble sugars, plus polymeric carbon sources (spruce powder, cellulose), on P. placenta gene expression in liquid cultures. Expression of ORs was strictly (aox1, cro5) or progressively repressed over time (qrd1, lcc1) by all soluble sugars, including cellobiose, but not by polymeric sources. Simple sugars repressed hemicellulase gene expression over time, but these sugars did not repress cellulases. Cellulase genes were upregulated, however, along with hemicellulases in the presence of soluble cellobiose and in the presence of polymeric carbon sources, relative to starvation (carbon-free). This verifies an inducible cellulase system in P. placenta that lacks carbon catabolite repression (CCR), and it suggests that brown rot fungi use soluble sugars, particularly cellobiose, to cue a critical oxidative-hydrolytic transition. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Evidence for room temperature delignification of wood using hydrogen peroxide and manganese acetate as a catalyst.

    Science.gov (United States)

    Lucas, Marcel; Hanson, Susan K; Wagner, Gregory L; Kimball, David B; Rector, Kirk D

    2012-09-01

    Manganese acetate was found to catalyze the oxidative delignification of wood with hydrogen peroxide at room temperature. The delignification reaction was monitored by optical and Raman microscopy, and liquid chromatography/mass spectrometry. When exposed to H(2)O(2) and Mn(OAc)(3) in aqueous solution, poplar wood sections were converted into a fine powder-like material which consisted of individual wood cells within 4 days at room temperature and without agitation. Optical and Raman microscopy provided the spatial distribution of cellulose and lignin in the wood structure, and showed the preferential oxidation of lignin-rich middle lamellae. Raman spectra from the solid residue revealed a delignified and cellulose-rich material. Glucose yields following enzymatic hydrolysis were 20-40% higher in poplar sawdust pretreated with Mn(OAc)(3) for 2, 4, and 7 days at room temperature than those in sawdust exposed to water only for identical durations, suggesting the viability of this mild, inexpensive method for pretreatment of lignocellulosic biomass. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Variation in wood nutrients along a tropical soil fertility gradient.

    Science.gov (United States)

    Heineman, Katherine D; Turner, Benjamin L; Dalling, James W

    2016-07-01

    Wood contains the majority of the nutrients in tropical trees, yet controls over wood nutrient concentrations and their function are poorly understood. We measured wood nutrient concentrations in 106 tree species in 10 forest plots spanning a regional fertility gradient in Panama. For a subset of species, we quantified foliar nutrients and wood density to test whether wood nutrients scale with foliar nutrients at the species level, or wood nutrient storage increases with wood density as predicted by the wood economics spectrum. Wood nutrient concentrations varied enormously among species from fourfold in nitrogen (N) to > 30-fold in calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P). Community-weighted mean wood nutrient concentrations correlated positively with soil Ca, K, Mg and P concentrations. Wood nutrients scaled positively with leaf nutrients, supporting the hypothesis that nutrient allocation is conserved across plant organs. Wood P was most sensitive to variation in soil nutrient availability, and significant radial declines in wood P indicated that tropical trees retranslocate P as sapwood transitions to heartwood. Wood P decreased with increasing wood density, suggesting that low wood P and dense wood are traits associated with tree species persistence on low fertility soils. Substantial variation among species and communities in wood nutrient concentrations suggests that allocation of nutrients to wood, especially P, influences species distributions and nutrient dynamics in tropical forests. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  12. In vivo validation of the multicomponent powder (Vitachelox® against the deposition of polluting ions

    Directory of Open Access Journals (Sweden)

    Giacomelli L

    2018-03-01

    Full Text Available Luca Giacomelli,1 Stefano Togni,2 Martino Meneghin,2 Roberto Eggenhöffner,1 Giada Maramaldi2 1Department of Surgical Science and Integrated Diagnostics, University of Genoa, Genoa, Italy; 2Indena S.p.A, Milan, Italy Purpose: The purpose of this in vivo study is to evaluate the acute clinical application of a multicomponent powder (Vitachelox®, including three naturally occurring standardized extracts rich in polyphenols (grape seed extract, green tea extract, oak wood/bark extract, on healthy volunteers by measuring prevention of any metal deposition within the stratum corneum (SC following a 6-h exposure period in a polluted environment.Patients and methods: In this in vivo study, we evaluated the skin protective activity of the multicomponent powder formulated in a base emulsion compared to a relevant placebo cream. Using the tape stripping method, SC samples of face skin obtained from 30 healthy volunteers were compared following a 6-h exposure in a polluted area.Results: No statistically significant variations on the amount of heavy metals were found in the samples of SC cells obtained from the hemi-faces treated with the multicomponent powder, with respect to baseline. On the contrary, a significantly higher concentration of heavy metals was found in the cells samples obtained from the hemi-faces treated with the placebo cream. In particular, an increased concentration of heavy metals superior to 100% were found for iron and zinc (+130.2% and +142.6%, respectively; p<0.001.Conclusion: This in vivo study validates and extends previous in vitro findings, indicating that the multicomponent powder allows the prevention of any metal deposition within the SC following exposure in a polluted environment. Our results suggest that the test product could play an effective role in counteracting skin damages induced by air pollution. Keywords: air pollution, heavy metals, oxidative stress, polyphenols, green tea extract, oak wood extract, grape seed

  13. The Wood Anatomy of Rubiaceae tribes Anthospermeae and Paederieae

    NARCIS (Netherlands)

    Koek-Noorman, J.; Puff, Ch.

    1983-01-01

    Detailed wood anatomical descriptions are given for the genera Anthospermum, Nenax, Phyllis, Carpacoce, Coprosma, Neogaillonia, Crocyllis, Plocama and Spermadictyon, and miscellaneous wood anatomical data on the genera Normandia, Pomax, Opercularia, Leptodermis and Aitchisonia. The wood anatomical

  14. The role of wood anatomy in phylogeny reconstruction of Ericales

    NARCIS (Netherlands)

    Lens, F.; Schönenberger, J.; Baas, P.; Jansen, S.; Smets, E.

    2007-01-01

    The systematic significance of wood anatomical characters within Ericales is evaluated using separate and combined parsimony analyses including 23 wood characters and 3945 informative molecular characters. Analyses of wood features alone result in poorly resolved and conflicting topologies. However,

  15. Isostatic pressing of metal powders

    International Nuclear Information System (INIS)

    Cytermann, R.; Auguin, B.; Defresne, A.; Gilles, P.

    1975-01-01

    The process of powders compaction is of great technical importance for the attainment of sintered bodies of high density and strength, or of bodies with controlled porosity. For this purpose, different carbonyl nickel and carbonyl iron powders were isostatically compacted at pressures from 50 to 1300 MN/m 2 (0.5-13kbars). The density of compacts was determined by stereology (quantitative microscopic analysis) and weighing. The two methods were found to be in very good agreement and permit to correlate the density of the compact with the applied pressure, while differentiating the stages of compaction (particle rearrangement, local and homogeneous plastic flow) and showing off the influence of material properties (particle size distribution, particle sphape, ability of the particles to deform, yield stress required for deformation, etc...) The way from one stage to the other was corroborated by scanning electron microscope observation and X-rays diffraction. Electrical resistance and tensile strength measurements were also carried out and permitted to correlate these parameters and the applied pressure [fr

  16. Smart particle production, characterization and powder forensics

    OpenAIRE

    Fang, Yuan

    2017-01-01

    Powdered food ingredients are common yet important in our daily life. The most well-known method to produce these powdered products is via spray drying. Nowadays, it is possible to customize the spray dried products with desired nutrition/physiochemical properties according to the requirements and demands of the consumer market. Powders resulting from different processes (or different process conditions) vary significantly in composition and the functional behaviours. This renders traditional...

  17. In-house characterization of protein powder

    DEFF Research Database (Denmark)

    Hartmann, Christian Grundahl; Nielsen, Ole Faurskov; Ståhl, Kenny

    2010-01-01

    X-ray powder diffraction patterns of lysozyme and insulin were recorded on a standard in-house powder diffractometer. The experimental powder diffraction patterns were compared with patterns calculated from Protein Data Bank coordinate data. Good agreement was obtained by including straightforward...... to include calculated H-atom positions did not improve the overall fit and was abandoned. The method devised was shown to be a quick and convenient tool for distinguishing precipitates and polymorphs of proteins....

  18. Strength of anisotropic wood and synthetic materials. [plywood, laminated wood plastics, glass fiber reinforced plastics, polymeric film, and natural wood

    Science.gov (United States)

    Ashkenazi, Y. K.

    1981-01-01

    The possibility of using general formulas for determining the strength of different anisotropic materials is considered, and theoretical formulas are applied and confirmed by results of tests on various nonmetallic materials. Data are cited on the strength of wood, plywood, laminated wood plastics, fiber glass-reinforced plastics and directed polymer films.

  19. CVD carbon powders modified by ball milling

    Directory of Open Access Journals (Sweden)

    Kazmierczak Tomasz

    2015-09-01

    Full Text Available Carbon powders produced using a plasma assisted chemical vapor deposition (CVD methods are an interesting subject of research. One of the most interesting methods of synthesizing these powders is using radio frequency plasma. This method, originally used in deposition of carbon films containing different sp2/sp3 ratios, also makes possible to produce carbon structures in the form of powder. Results of research related to the mechanical modification of these powders have been presented. The powders were modified using a planetary ball mill with varying parameters, such as milling speed, time, ball/powder mass ratio and additional liquids. Changes in morphology and particle sizes were measured using scanning electron microscopy and dynamic light scattering. Phase composition was analyzed using Raman spectroscopy. The influence of individual parameters on the modification outcome was estimated using statistical method. The research proved that the size of obtained powders is mostly influenced by the milling speed and the amount of balls. Powders tend to form conglomerates sized up to hundreds of micrometers. Additionally, it is possible to obtain nanopowders with the size around 100 nm. Furthermore, application of additional liquid, i.e. water in the process reduces the graphitization of the powder, which takes place during dry milling.

  20. Preparation techniques for ceramic waste form powder

    International Nuclear Information System (INIS)

    Hash, M.C.; Pereira, C.; Lewis, M.A.

    1997-01-01

    The electrometallurgical treatment of spent nuclear fuels result in a chloride waste salt requiring geologic disposal. Argonne National Laboratory (ANL) is developing ceramic waste forms which can incorporate this waste. Currently, zeolite- or sodalite-glass composites are produced by hot isostatic pressing (HIP) techniques. Powder preparations include dehydration of the raw zeolite powders, hot blending of these zeolite powders and secondary additives. Various approaches are being pursued to achieve adequate mixing, and the resulting powders have been HIPed and characterized for leach resistance, phase equilibria, and physical integrity

  1. Atom probe tomography analysis of WC powder

    Energy Technology Data Exchange (ETDEWEB)

    Weidow, Jonathan, E-mail: jonathan.weidow@chalmers.se [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, A-1060 Wien (Austria)

    2013-09-15

    A tantalum doped tungsten carbide powder, (W,Ta)C, was prepared with the purpose to maximise the amount of Ta in the hexagonal mixed crystal carbide. Atom probe tomography (APT) was considered to be the best technique to quantitatively measure the amount of Ta within this carbide. As the carbide powder consisted in the form of very small particles (<1 μm), a method to produce APT specimens of such a powder was developed. The powder was at first embedded in copper and a FIB-SEM workstation was used to make an in-situ lift-out from a selected powder particle. The powder particle was then deposited on a post made from a WC-Co based cemented carbide specimen. With the use of a laser assisted atom probe, it was shown that the method is working and the Ta content of the (W,Ta)C could be measured quantitatively. - Highlights: ► Method for producing atom probe tomography specimens of powders was developed. ► Method was successfully implemented on (W,Ta)C powder. ► Method can possibly be implemented on completely other powders.

  2. Manufacturing methods and magnetic characteristics of magnetic wood

    International Nuclear Information System (INIS)

    Oka, H.; Hojo, A.; Osada, H.; Namizaki, Y.; Taniuchi, H.

    2004-01-01

    The relationship between wood construction and DC magnetic characteristics for three types of magnetic wood was experimentally investigated. The results show that the magnetic characteristics of each type of magnetic wood are dependent on the magnetic materials, the density of the magnetic material and the construction of the wood. Furthermore, it was determined that the relationship between the fiber direction and the magnetic path direction of the magnetic wood influenced the wood's magnetic characteristics

  3. Social Housing: wood prefabrication techniques

    Directory of Open Access Journals (Sweden)

    Tiziana Ferrante

    2012-10-01

    Full Text Available Student housing, a particular and quite significant part of social housing, and innovation in processing and production of industrial building components made of a material (wood not adequately inquired: two fields of research that have been explored for a long time allowing here to share and compare experiences gained thus far. By a selection of samples of wooden student housing in Europe we have documented the performances of this material and we have underlined, at the same time, through what happens abroad, the need of an organic national social housing plan that can meet an unsatisfied demand and boost the construction industry during this particular stage of economic crisis.

  4. Gascoigne Wood - eagle or albatross?

    Energy Technology Data Exchange (ETDEWEB)

    Hoy, H.D.; Lowery, P.A. [RJB Mining (United Kingdom) Limited (United Kingdom). Gascoigne Wood Mine

    1995-11-01

    This paper reviews the history of Gascoigne Wood coal receiving and dispatch centre from conception through to the present. The design and development of the infrastructure is described with particular reference to the spine tunnels, major engineering installations and the system modifications undertaken to maintain a marketable product. Performance parameters are examined and a comparison made of the attributable and surface costs of a Selby Complex Mine with a similar size individual colliery. Finally, the changes envisaged in the future are discussed. 10 figs., 4 tabs.

  5. Effect of Wood Fillers on the Viscoelastic and Thermophysical Properties of HDPE-Wood Composite

    Directory of Open Access Journals (Sweden)

    M. Tazi

    2016-01-01

    Full Text Available Wood polymer composites (WPC have well proven their applicability in several fields of the plasturgy sector, due to their aesthetics and low maintenance costs. However, for plasturgy applications, the characterization of viscoelastic behavior and thermomechanical and thermophysical properties of WPC with the temperature and wood filler contents is essential. Therefore, the processability of polymer composites made up with different percentage of wood particles needs a better understanding of materials behaviors in accordance with temperature and wood particles contents. To this end, a numerical analysis of the viscoelastic, mechanical, and thermophysical properties of composite composed of high density polyethylene (HDPE reinforced with soft wood particles is evaluated.

  6. Structural Evaluation Procedures for Heavy Wood Truss Structures

    National Research Council Canada - National Science Library

    Issa, Mohsen

    1998-01-01

    .... An evaluation procedure for wood structures differs from conventional methods used in steel, concrete, and masonry structures because, in wood construction, the allowable stresses used in design...

  7. Thermal Properties of Wood-Plastic Composites Prepared from Hemicellulose-extracted Wood Flour

    Directory of Open Access Journals (Sweden)

    A.A. Enayati

    2013-01-01

    Full Text Available Hemicellulose of Southern Yellow Pine wood spices was extracted by pressurized hot water at three different temperatures: 140°C, 155°C and 170°C. Compounding with PP (polypropylene was performed by extrusion after preparing wood flour and sieving to determine its mesh size. The ratio of wood to polymer was 50:50 based on oven-dry weight of wood flour. All extraction treatments and control samples were compounded under two sets of conditions, without and with 2% MAPP as coupling agent. Injection molding was used to make tensile test samples (dogbone from the pellets made by extrusion. Thermal properties of wood-plastic composites were studied by TGA and DSC while the thermal stability of pretreated wood flours, PP and MAPP were studied by TGA as well. The greater weight loss of wood materials was an indication that higher treatment temperature increases the extractability of hemicellulose. The removal of hemicellulose by extraction improves thermal stability of wood flour, especially for extraction at 170°C. Wood-plastic composites made from extracted fibers at 170°C showed the highest thermal stability. Coupling agent did not have a significant effect on thermal stability but it improved the degree of crystallinity of the composites.Surface roughness of wood fiber increased after treatment. Extraction of hemicellulose increased the degree of crystallinity but it was not significant except for samples from treated wood flour at 170°C and with MAPP.

  8. Effect of Wood Flour Addition on the Pore Volume and BET Surface Area Properties of the Prepared Gamma Alumina (ɤ-Al2O3 Extrudates Used in Catalyst Carriers

    Directory of Open Access Journals (Sweden)

    Alaa D. Jawad Al-Bayati

    2015-11-01

    Full Text Available The effect of Wood Flour addition to the gamma alumina powder used in the preparation of gamma alumina (ɤ-Al2O3 catalyst carrier extrudates on the pore volume and BET surface area physical properties was investigated. Two parameters which are size of wood flour particles and its quantity were studied. The sizes of wood flour particles used are 150 µm, 212 µm and 500 µm and the weight percentage added to the gamma alumina powder during the preparation of the extrudates are (1%, 3%, 5% and 10%. The results showed that the addition of wood flour to the gamma alumina powder in order to get gamma alumina extrudates used as catalyst carrier is one of the successful methods to improve the pore volume and BET surface area of the alumina extrudates. The size of wood flour particles and its quantity have main effect on the above texture properties. The smaller the size of wood flour leaded to higher BET surface area, where maximum BET surface area of 127.3 m2/g was got with addition 10% by weight wood flour of 150µm particle size. BET surface area for the same addition percentage of 10% resulted to 114.5m2/g and 105.2m2/g when adding wood flour of 212 µm and 500 µm particle sizes respectively. The weight percentage of wood flour addition has an effect on the BET surface area, where the 3% addition gives maximum BET surface area when the size of the wood flour particles is 500 µm. Regarding the pore volume property for the gamma alumina prepared extrudates, the results showed that the pore volume of the extrudates increased to 0.83 cm3/g and 1.0 cm3/g when 10% wood flour of 150 µm and 500 µm particle sizes were added respectively. The maximum BET surface area was reached when 10% wood flour of 150 µm particle size was added, and the maximum pore volume was reached when 10% wood flour of 500 µm particle size was added, the increase percentage for the BET surface area and pore volume is more than 40% and 400% respectively.

  9. Bacteria in decomposing wood and their interactions with wood-decay fungi.

    Science.gov (United States)

    Johnston, Sarah R; Boddy, Lynne; Weightman, Andrew J

    2016-11-01

    The fungal community within dead wood has received considerable study, but far less attention has been paid to bacteria in the same habitat. Bacteria have long been known to inhabit decomposing wood, but much remains underexplored about their identity and ecology. Bacteria within the dead wood environment must interact with wood-decay fungi, but again, very little is known about the form this takes; there are indications of both antagonistic and beneficial interactions within this fungal microbiome. Fungi are hypothesised to play an important role in shaping bacterial communities in wood, and conversely, bacteria may affect wood-decay fungi in a variety of ways. This minireview considers what is currently known about bacteria in wood and their interactions with fungi, and proposes possible associations based on examples from other habitats. It aims to identify key knowledge gaps and pressing questions for future research. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Relationship between ecological indicators and teak wood ...

    African Journals Online (AJOL)

    Relationship between ecological indicators and teak wood characteristics in Tchorogo plantation (Togo) ... International Journal of Biological and Chemical Sciences ... Results showed that teak productivity level, which is linked to the fibre properties of teak wood varied significantly (F749,2=71.81; P<0.001 for fibre length; ...

  11. Analysis of acetylated wood by electron microscopy

    NARCIS (Netherlands)

    Sander, C.; Beckers, E.P.J.; Militz, H.; Veenendaal, van W.

    2003-01-01

    The properties of acetylated solid wood were investigated earlier, in particular the anti-shrink efficiency and the resistance against decay. This study focuses on the possible changes and damage to the wood structure due to an acetylation process leading to weight per cent gains of up to 20%.

  12. Chapter 13:Wood/Nonwood Thermoplastic Composites

    Science.gov (United States)

    Craig M. Clemons; Roger M. Rowell; David Plackett; B. Kristoffer Segerholm

    2013-01-01

    Composites made from wood, other biomass resources and polymers have existed for a long time but the nature of many of these composites has changed in recent decades. Wood-thermoset composites date to the early 1900s. "Thermosets" or thermosetting polymers are plastics that, once cured, cannot be remelted by heating. These include cured resins such as epoxies...

  13. Leonard Wood, Operational Artist or Scheming Careerist?

    Science.gov (United States)

    2012-12-06

    Enterprise, and Labour : (GP Putnam’s sons, 1899). Quoted in Lane, Armed Progressive: General Leonard Wood, 58. 79 Ibid., 58. 21 and accountable...enslave pacified Moros. “He [Wood] and other officers expressed satisfaction with the results of these devastating campaigns.”155 The criticism that...

  14. Potential for Biobased Adhesives in Wood Bonding

    Science.gov (United States)

    Charles R. Frihart

    2016-01-01

    There has been a resurgence of interest and research on using bio-based materials as wood adhesives; however, they have achieved only limited market acceptance. To better understand this low level of replacement, it is important to understand why adhesives work or fail in moisture durability tests. A holistic model for wood adhesives has been developed that clarifies...

  15. Wood mimetic hydrogel beads for enzyme immobilization.

    Science.gov (United States)

    Park, Saerom; Kim, Sung Hee; Won, Keehoon; Choi, Joon Weon; Kim, Yong Hwan; Kim, Hyung Joo; Yang, Yung-Hun; Lee, Sang Hyun

    2015-01-22

    Wood component-based composite hydrogels have potential applications in biomedical fields owing to their low cost, biodegradability, and biocompatibility. The controllable properties of wood mimetic composites containing three major wood components are useful for enzyme immobilization. Here, lipase from Candida rugosa was entrapped in wood mimetic beads containing cellulose, xylan, and lignin by dissolving wood components with lipase in [Emim][Ac], followed by reconstitution. Lipase entrapped in cellulose/xylan/lignin beads in a 5:3:2 ratio showed the highest activity; this ratio is very similar to that in natural wood. The lipase entrapped in various wood mimetic beads showed increased thermal and pH stability. The half-life times of lipase entrapped in cellulose/alkali lignin hydrogel were 31- and 82-times higher than those of free lipase during incubation under denaturing conditions of high temperature and low pH, respectively. Owing to their biocompatibility, biodegradability, and controllable properties, wood mimetic hydrogel beads can be used to immobilize various enzymes for applications in the biomedical, bioelectronic, and biocatalytic fields. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Micromechanical measurement of wood substructure properties.

    Science.gov (United States)

    David E. Kretschmann; Troy W. Schmidt; Roderic S. Lakes; Steven M. Cramer

    2002-01-01

    The annual rings of softwoods are visually obvious and represent cylindrical layers of primarily cellulosic material that possess significantly different properties. For simplicity, wood construction products are designed assuming a material homogeneity that does not exist. As rapidly grown plantation trees are used for wood products, fewer rings are contained in an...

  17. Wood properties from roundwood to timber engineering

    NARCIS (Netherlands)

    van de Kuilen, J.W.G.; Eberhardsteiner, J.; Winter, W.; Fadai, A.; Pöll, M.

    2016-01-01

    Measuring and assessing wood properties during the production chain is getting more and more important for an optimal use of the resource. Over the years, research has been performed with the focus on establishing important wood properties, with the final goal of an

  18. Use of nanofillers in wood coatings

    DEFF Research Database (Denmark)

    Nikolic, Miroslav; Lawther, John Mark; Sanadi, Anand Ramesh

    2015-01-01

    Wood has been used for thousands of years and remains an important material in the construction industry, most often protected with coatings. Development of nanotechnology allows further improvements or new performance properties to be achieved in wood coatings. Increased UV protection...

  19. The market for wood picnic structures.

    Science.gov (United States)

    Jerry A. Sesco

    1969-01-01

    Most of the picnic structures in six north-central states studied were constructed of wood. Service life of structure varied greatly. Vandalism and decay were the major reasons for repairing and replacing picnic tables. More than half the tables were made by the recreation agencies themselves. These results describe a market that existing and potential wood...

  20. Wood decay and the cleanup crew

    Science.gov (United States)

    Kevin T. Smith; Jessie A. Glaeser

    2017-01-01

    Arborists are encouraged to recognize the wood-decay process as an important factor in tree health and public safety. Technical experts who develop training materials to recognize wood-decay processes in living trees are frequently forest pathologists. Much of the history of forest pathology was to support production of sound, high-quality timber. That heritage is...

  1. Wood as a sustainable building material

    Science.gov (United States)

    Robert H. Falk

    2010-01-01

    Few building materials possess the environmental benefits of wood. It is not only our most widely used building material but also one with characteristics that make it suitable for a wide range of applications. As described in the many chapters of this handbook, efficient, durable, and useful wood products produced from trees can range from a minimally processed log at...

  2. Successful approaches to recycling urban wood waste

    Science.gov (United States)

    Solid Waste Association of North America

    2002-01-01

    This report presents eight case studies of successful urban wood waste recycling projects and businesses. These studies document the success of recovered products such as lumber and lumber products, mulch, boiler fuel, and alternative cover for landfills. Overall, wood waste accounts for about 17% of the total waste received at municipal solid waste landfills in the...

  3. Factors influencing wood mobilization in streams

    Science.gov (United States)

    Merten, Eric; Finlay, Jacques; Johnson, Lucinda; Newman, Raymond; Stefan, Heinz; Vondracek, Bruce

    2010-10-01

    Natural pieces of wood provide a variety of ecosystem functions in streams including habitat, organic matter retention, increased hyporheic exchange and transient storage, and enhanced hydraulic and geomorphic heterogeneity. Wood mobilization is a critical process in determining the residence time of wood. We documented the characteristics and locations of 865 natural wood pieces (>0.05 m in diameter for a portion >1 m in length) in nine streams along the north shore of Lake Superior in Minnesota. We determined the locations of the pieces again after an overbank stormflow event to determine the factors that influenced mobilization of stationary wood pieces in natural streams. Seven of 11 potential predictor variables were identified with multiple logistic regression as significant to mobilization: burial, effective depth, ratio of piece length to effective stream width (length ratio), bracing, rootwad presence, downstream force ratio, and draft ratio. The final model (P r2 = 0.39) indicated that wood mobilization under natural conditions is a complex function of both mechanical factors (burial, length ratio, bracing, rootwad presence, draft ratio) and hydraulic factors (effective depth, downstream force ratio). If stable pieces are a goal for stream management then features such as partial burial, low effective depth, high length relative to channel width, bracing against other objects (e.g., stream banks, trees, rocks, or larger wood pieces), and rootwads are desirable. Using the model equation from this study, stewards of natural resources can better manage in-stream wood for the benefit of stream ecosystems.

  4. Wood energy markets, 2011-2012

    Science.gov (United States)

    Francisco Aguilar; Rens Hartkamp; Warren Mabee; Kenneth Skog

    2012-01-01

    To celebrate the 2012 International Year of Sustainable Energy for All, in this chapter we consider in some depth the sustainability of wood energy. To do so, we evaluate the traditional economic, environmental and social dimensions of the sustainability concept. We also address how public policy has influenced wood energy sustainability across the UNECE region.

  5. Chapter 01: Wood identification and pattern recognition

    Science.gov (United States)

    Alex Wiedenhoeft

    2011-01-01

    Wood identification is a combination of art and science. Although the bulk of this manual focuses on the scientific characteristics used to make accurate field identifications of wood, the contribution of the artistic component to the identification process should be neither overlooked nor understated. Though the accumulation of scientific knowledge and experience is...

  6. Bioremediation of treated wood with bacteria

    Science.gov (United States)

    Carol A. Clausen

    2006-01-01

    This chapter reviews prior research in the field of bacterial bioremediation for wood treated with oilborne and inorganic preservatives. Current state of the art is summarized along with potential benefits and pitfalls of a pilot-scale bioremediation process for CCA-treated waste wood.

  7. Radial wood Allocation in Schizolobium Parahyba

    Science.gov (United States)

    G. Bruce Williamson; Michael C. Wiemann; James P. Geaghan

    2012-01-01

    The diversity of tropical trees has captivated botanists for centuries. Woods of difterent species, not only differ in appearance, but also in functional traits-density, porosity and strength-characteristics that relate to various plant functions such as support and conduction. The specific gravity (SG) of wood is a species' trait that integrates mechanical...

  8. WGDB: Wood Gene Database with search interface.

    Science.gov (United States)

    Goyal, Neha; Ginwal, H S

    2014-01-01

    Wood quality can be defined in terms of particular end use with the involvement of several traits. Over the last fifteen years researchers have assessed the wood quality traits in forest trees. The wood quality was categorized as: cell wall biochemical traits, fibre properties include the microfibril angle, density and stiffness in loblolly pine [1]. The user friendly and an open-access database has been developed named Wood Gene Database (WGDB) for describing the wood genes along the information of protein and published research articles. It contains 720 wood genes from species namely Pinus, Deodar, fast growing trees namely Poplar, Eucalyptus. WGDB designed to encompass the majority of publicly accessible genes codes for cellulose, hemicellulose and lignin in tree species which are responsive to wood formation and quality. It is an interactive platform for collecting, managing and searching the specific wood genes; it also enables the data mining relate to the genomic information specifically in Arabidopsis thaliana, Populus trichocarpa, Eucalyptus grandis, Pinus taeda, Pinus radiata, Cedrus deodara, Cedrus atlantica. For user convenience, this database is cross linked with public databases namely NCBI, EMBL & Dendrome with the search engine Google for making it more informative and provides bioinformatics tools named BLAST,COBALT. The database is freely available on www.wgdb.in.

  9. Wood Variety Recognition on Mobile Devices

    Czech Academy of Sciences Publication Activity Database

    Vácha, Pavel; Haindl, Michal

    2013-01-01

    Roč. 2013, č. 93 (2013), s. 52-52 ISSN 0926-4981 R&D Projects: GA ČR GA102/08/0593 Institutional support: RVO:67985556 Keywords : wood recognition * Markov random fields Subject RIV: BD - Theory of Information http:// library .utia.cas.cz/separaty/2013/RO/vacha-wood variety recognition on mobile devices.pdf

  10. Wood decomposition as influenced by invertebrates

    Science.gov (United States)

    Michael D. Ulyshen

    2014-01-01

    The diversity and habitat requirements of invertebrates associated with dead wood have been the subjects of hundreds of studies in recent years but we still know very little about the ecological or economic importance of these organisms. The purpose of this review is to examine whether, how and to what extent invertebrates affect wood decomposition in terrestrial...

  11. Factors influencing wood mobilization in Minnesota streams

    Science.gov (United States)

    Merten, Eric; Finlay, Jacques; Johnson, Lucinda; Newman, Raymond; Stefan, Heinz; Vondracek, Bruce C.

    2010-01-01

    Natural pieces of wood provide a variety of ecosystem functions in streams including habitat, organic matter retention, increased hyporheic exchange and transient storage, and enhanced hydraulic and geomorphic heterogeneity. Wood mobilization is a critical process in determining the residence time of wood. We documented the characteristics and locations of 865 natural wood pieces (>0.05 m in diameter for a portion >1 m in length) in nine streams along the north shore of Lake Superior in Minnesota. We determined the locations of the pieces again after an overbank stormflow event to determine the factors that influenced mobilization of stationary wood pieces in natural streams. Seven of 11 potential predictor variables were identified with multiple logistic regression as significant to mobilization: burial, effective depth, ratio of piece length to effective stream width (length ratio), bracing, rootwad presence, downstream force ratio, and draft ratio. The final model (P< 0.001, r2 = 0.39) indicated that wood mobilization under natural conditions is a complex function of both mechanical factors (burial, length ratio, bracing, rootwad presence, draft ratio) and hydraulic factors (effective depth, downstream force ratio). If stable pieces are a goal for stream management then features such as partial burial, low effective depth, high length relative to channel width, bracing against other objects (e.g., stream banks, trees, rocks, or larger wood pieces), and rootwads are desirable. Using the model equation from this study, stewards of natural resources can better manage in-stream wood for the benefit of stream ecosystems.

  12. Kraft pulping of industrial wood waste

    Science.gov (United States)

    Aziz. Ahmed; Masood. Akhtar; Gary C. Myers; Gary M. Scott

    1998-01-01

    Most of the approximately 25 to 30 million tons of industrial wood waste generated in the United States per year is burned for energy and/or landfilled. In this study, kraft pulp from industrial wood waste was evaluated and compared with softwood (loblolly pine, Douglas-fir) and hardwood (aspen) pulp. Pulp bleachability was also evaluated. Compared to loblolly pine...

  13. Environmental education on wood preservatives and preservative ...

    African Journals Online (AJOL)

    Forest products specialists are often asked about the perceived risks and environmental costs of treated wood products. Evidently, the civil society is ignorant of the fact that preservative treated wood products (PTWP) are not as lethal as pesticides. In this paper, a careful review is made of the environmental and health ...

  14. COMPOSITES FROM RECYCLED WOOD AND PLASTICS

    Science.gov (United States)

    The ultimate goal of this research was to develop technology to convert recycled wood fiber and plastics into durable products that are recyclable and otherwise environmentally friendly. Two processing technologies were used to prepare wood-plastic composites: air-laying and melt...

  15. Waste-wood-derived fillers for plastics

    Science.gov (United States)

    Brent English; Craig M. Clemons; Nicole Stark; James P. Schneider

    1996-01-01

    Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts. Such thermoplastics are usually provided to the end-user as a precompounded, pelletized feedstock. Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper...

  16. Finishability of CCA pressure-treated wood

    Science.gov (United States)

    Alan Ross; Richard Carlson; William Feist; Steven Bussjaeger

    2000-01-01

    Thus, a need arose for the development of surface finishes for CCA-treated wood that could address the special requirements of this substrate and provide protection against the ravages of water, sunlight, mildew, and other aspects of weathering and wear. Initially, this need was not addressed, most wood preserving companies had little expertise in surface finishes and...

  17. Wood products research in the USA

    Science.gov (United States)

    Theodore Wegner

    2010-01-01

    Forest biomass conversion to biofuels and other value-added co-products; hyper-performance advanced composites custom tailored to end use requirements; advanced high performance wood-based structures; and nanomaterials and nano-enable high performance products from wood represent important research and development investment areas for the successful transformation of...

  18. Systematic wood anatomy of the Rosaceae

    NARCIS (Netherlands)

    Zhang, Shu-Yin

    1992-01-01

    The wood anatomy of the Rosaceae is surveyed and analysed, based on the study of 280 species (c. 500 specimens) belonging to 62 genera from different parts of the world. Eighteen wood anatomical characters have been used for a phenetic and phylogenetic classification. In the phenetic classification,

  19. Least cost supply strategies for wood chips

    DEFF Research Database (Denmark)

    Möller, Bernd

    The abstract presents a study based on a geographical information system, which produce  cost-supply curves by location for forest woods chips in Denmark.......The abstract presents a study based on a geographical information system, which produce  cost-supply curves by location for forest woods chips in Denmark....

  20. Reactivity and burnout of wood fuels

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo

    This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile...

  1. Business environment in the wood fuels field

    International Nuclear Information System (INIS)

    Laitinen, H.; Ranta, T.

    1995-01-01

    In this publication the business environment in the wood fuels sector and the internal and external factors affecting it are studied. It has been considered important to describe both the present situation and future possibilities of the business in order to develop it so that the planned increase in the use of wood fuels can be achieved

  2. Chapter 16: Soy Proteins as Wood Adhesives

    Science.gov (United States)

    Charles R. Frihart; Christopher G. Hunt; Michael J. Birkeland

    2014-01-01

    Protein adhesives allowed the development of bonded wood products such as plywood and glulam in the early 20th century. Petrochemical-based adhesives replaced proteins in most wood bonding applications because of lower cost, improved production efficiencies, and enhanced durability. However, several technological and environmental factors have led to a resurgence of...

  3. Scarcity on the market for wood wastes

    International Nuclear Information System (INIS)

    De Boer, A.

    2004-01-01

    An overview is given of the market for wood wastes in the Netherlands and how this affects the targets to use biomass. Several types of biomass must be imported, not only wood wastes, but also e.g. olive stones and cacao shells [nl

  4. Physiological Effects of Touching Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

    Full Text Available This study aimed to clarify the physiological effects of touching wood with the palm, in comparison with touching other materials on brain activity and autonomic nervous activity. Eighteen female university students (mean age, 21.7  ±  1.6 years participated in the study. As an indicator of brain activity, oxyhemoglobin (oxy-Hb concentrations were measured in the left/right prefrontal cortex using near-infrared time-resolved spectroscopy. Heart rate variability (HRV was used as an indicator of autonomic nervous activity. The high-frequency (HF component of HRV, which reflected parasympathetic nervous activity, and the low-frequency (LF/HF ratio, which reflected sympathetic nervous activity, were measured. Plates of uncoated white oak, marble, tile, and stainless steel were used as tactile stimuli. After sitting at rest with their eyes closed, participants touched the materials for 90 s. As a result, tactile stimulation with white oak significantly (1 decreased the oxy-Hb concentration in the left/right prefrontal cortex relative to marble, tile, and stainless steel and (2 increased ln(HF-reflected parasympathetic nervous activity relative to marble and stainless steel. In conclusion, our study revealed that touching wood with the palm calms prefrontal cortex activity and induces parasympathetic nervous activity more than other materials, thereby inducing physiological relaxation.

  5. Wood Identification of 18th Century Furniture. Interpreting Wood Naming Inventoires

    Directory of Open Access Journals (Sweden)

    Rocio Astrid BERNAL

    2011-09-01

    Full Text Available The 18th century Portuguese church furniture represents an extraordinary richness recognised worldwide, which demands safeguarding and valorisation. The identification of the wood of furniture artworks is the most important component for its comprehension and preservation. In this work wood anatomical characters of an 18th century Portuguese decorative furniture set from the Colegiada de São Martinho de Cedofeita, in Porto, were analysed to identify the woods used for manufacturing and to clarify their common names. Furthermore, the objectives were to recognise some of the criteria for choice of wood as well as the source of each wood. The woods identified from 16 fragments belong to Apuleia sp., Acacia sp., Neolamarckia sp. and Castanea sativa. Apuleia sp. and Acacia sp. woods most likely arrived from Brazil, while the Neolamarckia sp. woods likely arrived from India and the C. sativa woods from Portugal. The results are in accordance with the known Portuguese colonial sea routes of the 15th -18th centuries. Interestingly the terms found in the inventories can refer to finishing methods instead to the name of the woods, as for instance “oil wood” can refer to “oiled wood” or “linseed oiled wood”. The species choice may be related to the mechanical properties of the wood as well as the original tree size. Two large planks of Acacia sp. were used for the top of the “Portuguese arcaz”, and Apuleia sp. was found on main structural elements of this set of furniture, suggesting that wood colour was also important. Woods from Neolamarckia sp. and C. sativa, were also identified, being Castanea wood present only in the most recent pieces of the furniture set.

  6. Wood for energy production. Technology - environment - economy

    Energy Technology Data Exchange (ETDEWEB)

    Serup, H.; Falster, H.; Gamborg, C. [and others

    1999-10-01

    `Wood for Energy Production`, 2nd edition, is a readily understood guide to the application of wood in the Danish energy supply. The first edition was named `Wood Chips for Energy Production`. It describes the wood fuel from forest to consumer and provides a concise introduction to technological, environmental, and financial matters concerning heating systems for farms, institutions, district heating plants, and CHP plants. The individual sections deal with both conventional, well known technology, as well as the most recent technological advances in the field of CHP production. The purpose of this publication is to reach the largest possible audiance, and it is designed so that the layman may find its background information of special relevance. `Wood for Energy Production` is also available in German and Danish. (au)

  7. Mineralogy of Non-Silicified Fossil Wood

    Directory of Open Access Journals (Sweden)

    George E. Mustoe

    2018-03-01

    Full Text Available The best-known and most-studied petrified wood specimens are those that are mineralized with polymorphs of silica: opal-A, opal-C, chalcedony, and quartz. Less familiar are fossil woods preserved with non-silica minerals. This report reviews discoveries of woods mineralized with calcium carbonate, calcium phosphate, various iron and copper minerals, manganese oxide, fluorite, barite, natrolite, and smectite clay. Regardless of composition, the processes of mineralization involve the same factors: availability of dissolved elements, pH, Eh, and burial temperature. Permeability of the wood and anatomical features also plays important roles in determining mineralization. When precipitation occurs in several episodes, fossil wood may have complex mineralogy.

  8. Alaska Wood Biomass Energy Project Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Jonathan Bolling

    2009-03-02

    The purpose of the Craig Wood Fired Boiler Project is to use waste wood from local sawmilling operations to provide heat to local public buildings, in an effort to reduce the cost of operating those buildings, and put to productive use a byproduct from the wood milling process that otherwise presents an expense to local mills. The scope of the project included the acquisition of a wood boiler and the delivery systems to feed wood fuel to it, the construction of a building to house the boiler and delivery systems, and connection of the boiler facility to three buildings that will benefit from heat generated by the boiler: the Craig Aquatic Center, the Craig Elementary School, and the Craig Middle School buildings.

  9. Wood for energy production. Technology - environment - economy

    International Nuclear Information System (INIS)

    Serup, H.; Falster, H.; Gamborg, C.

    1999-01-01

    'Wood for Energy Production', 2nd edition, is a readily understood guide to the application of wood in the Danish energy supply. The first edition was named 'Wood Chips for Energy Production'. It describes the wood fuel from forest to consumer and provides a concise introduction to technological, environmental, and financial matters concerning heating systems for farms, institutions, district heating plants, and CHP plants. The individual sections deal with both conventional, well known technology, as well as the most recent technological advances in the field of CHP production. The purpose of this publication is to reach the largest possible audiance, and it is designed so that the layman may find its background information of special relevance. 'Wood for Energy Production' is also available in German and Danish. (au)

  10. 77 FR 28252 - Oral Dosage Form New Animal Drugs; Change of Sponsor; Griseofulvin Powder; Levamisole...

    Science.gov (United States)

    2012-05-14

    ... Sponsor; Griseofulvin Powder; Levamisole Hydrochloride Powder; Oxytetracycline Powder AGENCY: Food and... applications (ANADAs) for griseofulvin powder, levamisole hydrochloride soluble powder, and oxytetracycline..., ANADA 200-391 for Griseofulvin Powder, ANADAs 200-146 and 200-247 for Oxytetracycline Hydrochloride...

  11. Photocell modelling for thermophotovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Mayor, J.-C.; Durisch, W.; Grob, B.; Panitz, J.-C. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Goal of the modelling described here is the extrapolation of the performance characteristics of solar photocells to TPV working conditions. The model accounts for higher flux of radiation and for the higher temperatures reached in TPV converters. (author) 4 figs., 1 tab., 2 refs.

  12. Advances in powder diffraction crystallography

    International Nuclear Information System (INIS)

    Magneli, A.

    1986-01-01

    This is the first conference to be arranged within the framework of an agreement on scientific exchange and co-operation between l Academie des Sciences de l Institut de France and the Royal Swedish Academy of Sciences. The responsibility for the scientific program of the conference has been shared between members of the two Academies. The contributions include glimpses of the historical background and broad reviews of the present status of development and of recent work in powder crystallography. Reports are given on a number of studies, basic as well as applied in character, currently conducted in the two countries in a large variety of fields. Prospects of further developments in the area are also presented

  13. Reflection measurements for luminescent powders

    Science.gov (United States)

    Kroon, R. E.

    2018-04-01

    Luminescent materials are useful in applications varying from lighting and display technologies to document security features and medical research, amongst many others. Measurement of the excitation range is an important consideration, and absorption bands are often determined from a decrease in the measured diffuse reflectance of the material using a ultraviolet-visible (UV-vis) spectrophotometer with an integrating sphere. Such a system may provide questionable results when used to measure the reflectance of a luminescence material, which is demonstrated for a Tb doped silica phosphor, because the system cannot differentiate between the reflected light and luminescence. It is shown that more reliable results are achieved for this phosphor by measuring the reflectance using a synchronous zero-offset scan in a fluorescence spectrometer equipped with an integrating sphere. This method is therefore recommended instead of traditional reflectance measurements using a UV-vis spectrophotometer for luminescent powders.

  14. New detectors for powders diagrams

    International Nuclear Information System (INIS)

    Convert, P.

    1975-01-01

    During the last few years, all the classical neutron diffractometers for powders have used one or maybe a few counters. So, it takes a long time to obtain a diagram which causes many disadvantages: 1) very long experiments: one or two days (or flux on the sample about 10 6 n/cm 2 /a); 2) necessity of big samples: many cm 3 ; 3) necessity of having the whole diagram before changing anything in the experiment: magnetic field, temperature, quality of the sample; 4) necessity of having collimators of a few times ten minutes to obtain correct statistics in the diagram. Because of these disadvantages, several attempts have been made to speed up the experimental procedure such as using more counters, the detection of neutrons on a resistive wire, etc. In Grenoble, new position-sensitive detectors have been constructed using a digital technique

  15. Protons in hydrated protein powders

    International Nuclear Information System (INIS)

    Careri, G.; Bruni, F.; Consolini, G.

    1995-01-01

    Previous work from this laboratory has shown that hydrated lysozyme powders exhibit a dielectric behaviour, due to proton conductivity, explainable within the frame of percolation theory. Long range proton displacement appears only above the critical hydration for percolation, when the 2-dimensional motion takes place on fluctuating clusters of hydrogen-bonded water molecules adsorbed on the protein surface. The emergence of biological function, enzyme catalysis, was found to coincide with the critical hydration for percolation. More recently, we have evaluated the protonic conductivity of hydrated lysozyme powders, from room down to liquid N 2 temperature. In the high temperature limit a classical isotopic effect can be detected, and the conductivity follows the familiar Arrhenius law for thermally activated hopping. In the low temperature region the conductivity shows a temperature dependence in agreement with prediction by the theory of dissipative quantum tunneling. Below room temperature the static dielectric constant, and the dielectric relaxation time for charge transport showed an increase likely to be identified with the formation of a polaronic-solitonic species as predicted by the theory of proton transport in water chains, a species which displays a larger effective mass and a larger dipole moment that the usual hydrated protonic defects. The purpose of this paper is twofold. In the first section we present a tutorial report of some previous experimental results on proton displacement in slightly hydrated biological systems at room temperature, to show that in these systems the emergence of biological systems at room temperature, to show that in these systems the emergence of biological function coincides with the onset of percolative pathways in the water molecules network adsorbed on the surface of biomolecules. In the second section, we report on preliminary data on the dielectric relaxation of hydrated lysozyme below room temperature, to suggest

  16. Obtaining zircaloy powder through hydriding

    International Nuclear Information System (INIS)

    Dupim, Ivaldete da Silva; Moreira, Joao M.L.

    2009-01-01

    Zirconium alloys are good options for the metal matrix in dispersion fuels for power reactors due to their low thermal neutron absorption cross-section, good corrosion resistance, good mechanical strength and high thermal conductivity. A necessary step for obtaining such fuels is producing Zr alloy powder for the metal matrix composite material. This article presents results from the Zircaloy-4 hydrogenation tests with the purpose to embrittle the alloy as a first step for comminuting. Several hydrogenation tests were performed and studied through thermogravimetric analysis. They included H 2 pressures of 25 and 50 kPa and temperatures ranging between from 20 to 670 deg C. X-ray diffraction analysis showed in the hydrogenated samples the predominant presence of ZrH 2 and some ZrO 2 . Some kinetics parameters for the Zircaloy-4 hydrogenation reaction were obtained: the time required to reach the equilibrium state at the dwell temperature was about 100 minutes; the hydrogenation rate during the heating process from 20 to 670 deg C was about 21 mg/h, and at constant temperature of 670 deg C, the hydride rate was about 1.15 mg/h. The hydrogenation rate is largest during the heating process and most of it occurs during this period. After hydrogenated, the samples could easily be comminuted indicating that this is a possible technology to obtain Zircaloy powder. The results show that only few minutes of hydrogenation are necessary to reach the hydride levels required for comminuting the Zircaloy. The final hydride stoichiometry was between 2.7 and 2.8 H for each Zr atom in the sample (author)

  17. Preparation and Flame Retardant and Smoke Suppression Properties of Bamboo-Wood Hybrid Scrimber Filled with Calcium and Magnesium Nanoparticles

    Directory of Open Access Journals (Sweden)

    Bin Fu

    2014-01-01

    Full Text Available The physical and mechanical properties of bamboo-wood hybrid scrimber filled with different loadings of nanoparticles were studied. The effects of nanoparticles on flame retardant and smoke suppression properties of bamboo-wood hybrid scrimber were studied by means of thermogravimetric analysis (TGA, cone calorimeter (CONE, and scanning electron microscope (SEM. The results showed that the physical and mechanical properties of bamboo-wood hybrid scrimber were improved by adding a moderate loading of nanoparticles; the optimal loading of nanoparticles was 10%. The heat transfer in bamboo-wood hybrid scrimber was prevented and the escaping channel of combustible gas was blocked by the uniformly filling effect of nanoparticles. The gas concentration was diluted by the noncombustible gas produced by pyrolysis of nanoparticles; the combustion chain reaction was suppressed by highly reactive free radicals produced by pyrolysis of nanoparticles. The residual mass of bamboo-wood hybrid scrimber filled with nanoparticles in thermogravimetric (TG curve at 900 s and burned by method of cone calorimeter (CONE at 600 s was increased compared to that of untreated one, which showed that inorganic mineral powder has the effect of catalytic charring.

  18. Whey powder sterilization by ionizing irradiation

    International Nuclear Information System (INIS)

    Todorovic, M.; Salatic, Z.; Markov, S.

    1988-01-01

    Whey powder was sterilized by gamma waves application. As a source of irridiation isotope 60Co was used in Institute of Nuclear sciences B oris Kidrich , Vincha-Belgrade (Yugoslavia). The applied doses were: a, b, c, d, and e Kgy. The dose d was radappertization. After whey powder irradiation no adverse changes of organoleptic properties were noticed

  19. Preparation of silver powder through glycerol process

    Indian Academy of Sciences (India)

    High purity fine silver powder with uniform particle morphology was prepared through glycerol process. The process involves reduction of silver nitrate by glycerol under atmospheric conditions at a temperature below 175°C. Glycerol, in this process, acts as a solvent as well as a reducing agent. The powders prepared ...

  20. 21 CFR 73.1646 - Bronze powder.

    Science.gov (United States)

    2010-04-01

    ... percent. Maximum particle size 45µ (95 percent minimum). Aluminum, zinc, tin, and copper content shall be based on the weight of the dried powder after being thoroughly washed with ether. (c) Uses and restrictions. Bronze powder may be safely used in color externally applied drugs, including those intended for...

  1. Preparation of silver powder through glycerol process

    Indian Academy of Sciences (India)

    Unknown

    Abstract. High purity fine silver powder with uniform particle morphology was prepared through glycerol process. The process involves reduction of silver nitrate by glycerol under atmospheric conditions at a tem- perature below 175°C. Glycerol, in this process, acts as a solvent as well as a reducing agent. The powders.

  2. Solving Crystal Structures from Powder Diffraction Data

    DEFF Research Database (Denmark)

    Christensen, A. Nørlund; Lehmann, M. S.; Nielsen, Mogens

    1985-01-01

    High resolution powder data from both neutron and X-ray (synchrotron) sources have been used to estimate the possibility of direct structure determination from powder data. Two known structures were resolved by direct methods with neutron and X-ray data. With synchrotron X-ray data, the measured ...

  3. Antibacterial activity of some powdered herbal preparations ...

    African Journals Online (AJOL)

    Antibacterial activity of some powdered herbal preparations marketed in Kaduna metropolis. D Abba, H.I Inabo, S.E Yakubu, OS Olonitola. Abstract. The aim of the study was to investigate the phytochemical components and the antibacterial activities of some powdered herbal medicinal preparations sourced from identified ...

  4. CLAY SOIL STABILISATION USING POWDERED GLASS

    Directory of Open Access Journals (Sweden)

    J. OLUFOWOBI

    2014-10-01

    Full Text Available This paper assesses the stabilizing effect of powdered glass on clay soil. Broken waste glass was collected and ground into powder form suitable for addition to the clay soil in varying proportions namely 1%, 2%, 5%, 10% and 15% along with 15% cement (base by weight of the soil sample throughout. Consequently, the moisture content, specific gravity, particle size distribution and Atterberg limits tests were carried out to classify the soil using the ASSHTO classification system. Based on the results, the soil sample obtained corresponded to Group A-6 soils identified as ‘fair to poor’ soil type in terms of use as drainage and subgrade material. This justified stabilisation of the soil. Thereafter, compaction, California bearing ratio (CBR and direct shear tests were carried out on the soil with and without the addition of the powdered glass. The results showed improvement in the maximum dry density values on addition of the powdered glass and with corresponding gradual increase up to 5% glass powder content after which it started to decrease at 10% and 15% powdered glass content. The highest CBR values of 14.90% and 112.91% were obtained at 5% glass powder content and 5mm penetration for both the unsoaked and soaked treated samples respectively. The maximum cohesion and angle of internal friction values of 17.0 and 15.0 respectively were obtained at 10% glass powder content.

  5. Hydrothermal synthesis of fine oxide powders

    Indian Academy of Sciences (India)

    Unknown

    Inorganic powders are among the most important factors in many fields of materials such as ceramics, catalysts, medicines, food, etc. There are many papers and books related to powders preparation by many authors (Veale. 1972; Kato and Yamaguchi 1983; Vincenzini 1983;. Brinker et al 1984; Johnson Jr. 1987; Messing ...

  6. Jetting formation of the explosively loaded powders

    Science.gov (United States)

    Xue, Kun; Yu, Qiqi

    2017-10-01

    The formation of jet-like structures is widely reported in the explosive dispersal of powders surrounding high explosive charges. The jetting of powder beds initiates upon the shock wave reaches the outer edge of the charge. Opposed to the interface instability theory, a hollow sphere based bulk fragmentation model is established to account for the jetting of powders. A two-phase process, namely the nucleation and free expansion of hollow spheres, corresponds to the unloading process of the powder compact caused by the rarefaction waves which governs the fragmentation of the powders. The separation between adjacent hollow spheres dictates the size of the particle clusters, which would evolve into particle jets in later times. The predicted breakup time and the size of particle jets agree well with the experimental results. The increased moisture content in powders results in an increased number of particle jets. This moisture effect can be understood in light of the varied energy distribution due to the incompressibility of the interstitial liquids trapped inside the inter-grain pores. The portion of shock energy which is not consumed in the shock compaction of the wet powders would be dissipated through the viscous shear flows during the unloading of the wet powder compact. The excessive viscous energy requires to activate more localized shear flows, accordingly leading to an increased number of particle jets.

  7. Computational modelling for dry-powder inhalers

    NARCIS (Netherlands)

    Kröger, Ralf; Woolhouse, Robert; Becker, Michael; Wachtel, Herbert; de Boer, Anne; Horner, Marc

    2012-01-01

    Computational fluid dynamics (CFD) is a simulation tool used for modelling powder flow through inhalers to allow optimisation both of device design and drug powder. Here, Ralf Kröger, Consulting Senior CFD Engineer, ANSYS Germany GmbH; Marc Horner, Lead Technical Services Engineer, Healthcare,

  8. Autoclave heat treatment for prealloyed powder products

    Science.gov (United States)

    Freche, J. C.; Ashbrook, R. L.

    1973-01-01

    Technique could be applied directly to loose powders as part of hot pressing process of forming them to any required shapes. This would eliminate initial extrusion step commonly applied to prealloyed powders, substantially reduce cost of forming operation, and result in optimum properties.

  9. A breath actuated dry powder inhaler

    NARCIS (Netherlands)

    de Boer, Anne; Frijlink, Henderik W.; Hagedoorn, Paul

    2015-01-01

    A breath actuated dry powder inhaler with a single air circulation chamber for de-agglomeration of entrained powdered medicament using the energy of the inspiratory air stream. The chamber has a substantially polygonal sidewall, a plurality of air supply channels entering the chamber substantially

  10. Sysnthesis of powders by freeze-drying

    International Nuclear Information System (INIS)

    Johnson, S.M.; Gusman, M.I.; Hildenbrand, D.L.

    1988-01-01

    The freeze-drying method of synthesizing powders of the superconducting oxide YBa 2 Cu 3 O 7 - δ is described. This process produces homogeneous, submicron powders of high purity. The effects of salt selection, solution concentration and pH on the process are described. Some evaluation of the sintering behavior and the effects on critical current density are included

  11. Evaluating the Johanson theory for titanium powder

    CSIR Research Space (South Africa)

    Chikosha, S

    2015-05-01

    Full Text Available . In this study, the Johanson theory was used to determine the rolling parameters of titanium powder. Preliminary results of the nip angle, nip pressures and maximum horizontal pressures of the mill for the powder rolled on a 55mm diameter roll with roll gap sizes...

  12. Densification behavior of aluminum alloy powder mixed with zirconia powder inclusion under cold compaction

    International Nuclear Information System (INIS)

    Ryu, Hyun Seok; Lee, Sung Chul; Kim, Ki Tae

    2002-01-01

    Densification behavior of composite powders was investigated during cold compaction. Experimental data were obtained for aluminum alloy powder mixed with zirconia powder inclusion under triaxial compression. The cap model with constraint factors was implemented into a finite element program(ABAQUS) to simulate compaction responses of composite powders during cold compaction. Finite element results were compared with experimental data for densification behavior of composite powders under cold isostatic pressing and die compaction. The agreements between experimental data and finite element calculations from the cap model with constraint factors were good

  13. Powder diffraction crystallography of molecular solids.

    Science.gov (United States)

    Harris, Kenneth D M

    2012-01-01

    Many important crystalline solids cannot be prepared as single crystals of suitable size and quality for structural characterization by conventional single-crystal X-ray diffraction techniques and can instead be prepared only as microcrystalline powders. However, recent advances in techniques for determining crystal structures directly from powder X-ray diffraction data have created a unique opportunity for establishing structural properties of such materials. This chapter surveys the applications of powder X-ray diffraction across various aspects of structural and materials chemistry, focusing mainly on the opportunities that have emerged in recent years for carrying out complete crystal structure determination from powder X-ray diffraction data and giving particular emphasis to the case of molecular crystal structures. The current scope and future potential of powder X-ray diffraction as a strategy for crystal structure determination are discussed, and examples of applications across several disciplines of materials chemistry are presented.

  14. Sun drying of residual annatto seed powder

    Directory of Open Access Journals (Sweden)

    Dyego da Costa Santos

    2015-01-01

    Full Text Available Residual annatto seeds are waste from bixin extraction in the food, pharmaceutical and cosmetic industries. Most of this by-product is currently discarded; however, the use of these seeds in human foods through the elaboration of powder added to other commercial powders is seen as a viable option. This study aimed at drying of residual annatto powder, with and without the oil layer derived from the industrial extraction of bixin, fitting different mathematical models to experimental data and calculating the effective moisture diffusivity of the samples. Powder containing oil exhibited the shortest drying time, highest drying rate (≈ 5.0 kg kg-1 min-1 and highest effective diffusivity (6.49 × 10-12 m2 s-1. All mathematical models assessed were a suitable representation of the drying kinetics of powders with and without oil, with R2 above 0.99 and root mean square error values lower than 1.0.

  15. Thoria powder process development (LWBR Development Program)

    Energy Technology Data Exchange (ETDEWEB)

    Hutchison, C.R.; Lloyd, R.

    1979-10-01

    The development program to identify the critical parameters for the process of converting thorium nitrate solution into thoria powder is described. Thorium oxalate hexahydrate is precipitated from the reaction of thorium nitrate solution with oxalic acid. The resulting thorium oxalate hexahydrate slurry is filter pressed into a cake which is air calcined to form thoria powder. Changes in the critical processing parameters such as free nitric acid content of the thorium nitrate solution, precipitation temperature, and calcining temperature altered the thoria powder characteristics, and thus its capability for being fabricated into fuel pellets. The objective of the powder preparation effort was to obtain thoria powders which could be formed by conventional ceramic fabrication techniques into thoria and thoria-urania pellets of high density and high integrity having a nearly uniform large grain structure.

  16. Thoria powder process development (LWBR Development Program)

    International Nuclear Information System (INIS)

    Hutchison, C.R.; Lloyd, R.

    1979-10-01

    The development program to identify the critical parameters for the process of converting thorium nitrate solution into thoria powder is described. Thorium oxalate hexahydrate is precipitated from the reaction of thorium nitrate solution with oxalic acid. The resulting thorium oxalate hexahydrate slurry is filter pressed into a cake which is air calcined to form thoria powder. Changes in the critical processing parameters such as free nitric acid content of the thorium nitrate solution, precipitation temperature, and calcining temperature altered the thoria powder characteristics, and thus its capability for being fabricated into fuel pellets. The objective of the powder preparation effort was to obtain thoria powders which could be formed by conventional ceramic fabrication techniques into thoria and thoria-urania pellets of high density and high integrity having a nearly uniform large grain structure

  17. Application of powder rheometer to determine powder flow properties and lubrication efficiency of pharmaceutical particulate systems.

    Science.gov (United States)

    Navaneethan, Charu V; Missaghi, Shahrzad; Fassihi, Reza

    2005-10-19

    The objective of this study was to understand the behavior of particulate systems under different conditions of shear dynamics before and after granulation and to investigate the efficiency of powder lubrication. Three drug powders, metronidazole, colloidal bismuth citrate, and tetracycline hydrochloride, were chosen as model drugs representing noncohesive and cohesive powder systems. Each powder was individually granulated with microcrystalline cellulose and 5%PVP as a binder. One portion from each granulation was lubricated with different levels of magnesium stearate for 5 minutes. The powder characterization was performed on the plain powders, nonlubricated and lubricated granules using powder rheometer equipped with a helical blade rotating and moving under experimentally fixed set of parameters. The profiles of interaction during the force-distance measurements indicate that powder compresses, expands, and shears many times in a test cycle. Test profiles also clearly reveal existence of significant differences between cohesive and noncohesive powders. In all cases lubrication normalized the overall interactive nature of the powder by reducing peaks and valleys as observed from the profiles and reduced the frictional effect. The developed methods are easy to perform and will allow formulation scientists to better understand powder behavior and help in predicting potential impact of processing factors on particulate systems.

  18. Improving powder flow properties of a cohesive lactose monohydrate powder by intensive mechanical dry coating.

    Science.gov (United States)

    Zhou, Qi; Armstrong, Brian; Larson, Ian; Stewart, Peter J; Morton, David A V

    2010-02-01

    The objective of this study was to improve the cohesive lactose powder flowability. A cohesive lactose monohydrate powder was processed in either a tumbling blender or an intensive mechanical processor with either magnesium stearate or fumed silica. No substantial changes in particle size were detected by laser diffraction following either treatment. The untreated lactose sample exhibited very poor powder flow. Only limited improvements in powder flowability were indicated after the tumbling blending, intensive mechanical processing with the fumed silica or without additives. However, the intensive mechanical processing of the lactose sample with magnesium stearate demonstrated exceptionally large increases in both poured and tapped density as well as notable improvements in all powder flowability indicators examined. Our findings support the use of intensive mechanical processing technique as an effective method to coat cohesive pharmaceutical powders with selected additives, modify the surface nature of the particles, reduce the interparticle cohesive forces and hence improve powder flowability. The subtle differences in powder flow behaviour of lactose samples between the untreated and tumbling blended powders with magnesium stearate were only detected by the powder rheometer using its dynamic mode, indicating its potential advantages over traditional powder flow characterisation approaches. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

  19. How spectroscopy and microspectroscopy of degraded wood contribute to understand fungal wood decay.

    Science.gov (United States)

    Fackler, Karin; Schwanninger, Manfred

    2012-11-01

    Nuclear magnetic resonance, mid and near infrared, and ultra violet (UV) spectra of wood contain information on its chemistry and composition. When solid wood samples are analysed, information on the molecular structure of the lignocellulose complex of wood e.g. crystallinity of polysaccharides and the orientation of the polymers in wood cell walls can also be gained. UV and infrared spectroscopy allow also for spatially resolved spectroscopy, and state-of-the-art mapping and imaging systems have been able to provide local information on wood chemistry and structure at the level of wood cells (with IR) or cell wall layers (with UV). During the last decades, these methods have also proven useful to follow alterations of the composition, chemistry and physics of the substrate wood after fungi had grown on it as well as changes of the interactions between the wood polymers within the lignocellulose complex caused by decay fungi. This review provides an overview on how molecular spectroscopic methods could contribute to understand these degradation processes and were able to characterise and localise fungal wood decay in its various stages starting from the incipient and early ones even if the major share of research focussed on advanced decay. Practical issues such as requirements in terms of sample preparation and sample form and present examples of optimised data analysis will also be addressed to be able to detect and characterise the generally highly variable microbial degradation processes within their highly variable substrate wood.

  20. Properties of Wood Fibre-Polypropylene Composites: Effect of Wood Fibre Source

    Science.gov (United States)

    Butylina, Svetlana; Martikka, Ossi; Kärki, Timo

    2011-04-01

    This study examined the effect of type of wood fibre source on the physical and mechanical properties of wood fibre-polypropylene composites. Wood flour, fibres of heat-treated wood and pellets were used as sources of wood fibres in the manufacturing process. All studied wood fibre-polypropylene composites were made from 75% wood, 22% recycled polypropylene (PP) and 3% maleated polypropylene (MAPP). Wood fibre-polypropylene composites were compounded in a conical twin-screw extruder. Water absorption and thickness swelling were studied. Mechanical properties of the composites were characterised by tensile, flexural, and impact testing. Micromechanical deformation processes were investigated using scanning electron microscopy done on the fractured surfaces of broken samples. The durability of composites exposed to three accelerated cycles of water immersion, freezing and thawing was examined. The results showed that the density of the composites was a key factor governing water absorption and thickness swelling. A significant improvement in tensile strength, flexural strength, and Charpy impact strength was observed for composites reinforced with heat-treated fibre compared to composites reinforced with pellets and especially to wood flour reinforced composites. The flexural strength and dimensional stability performance reduced after exposure to freeze-thaw cycling for all composites, but the degree of these changes was dependent on the wood fibre source.

  1. Simple process to fabricate nitride alloy powders

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kim, Dong-Joo; Kim, Keon Sik; Rhee, Young Woo; Oh, Jang-Soo; Kim, Jong Hun; Koo, Yang Hyun

    2013-01-01

    Uranium mono-nitride (UN) is considered as a fuel material [1] for accident-tolerant fuel to compensate for the loss of fissile fuel material caused by adopting a thickened cladding such as SiC composites. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. Among them, a direct nitriding process of metal is more attractive because it has advantages in the mass production of high-purity powders and the reusing of expensive 15 N 2 gas. However, since metal uranium is usually fabricated in the form of bulk ingots, it has a drawback in the fabrication of fine powders. The Korea Atomic Energy Research Institute (KAERI) has a centrifugal atomisation technique to fabricate uranium and uranium alloy powders. In this study, a simple reaction method was tested to fabricate nitride fuel powders directly from uranium metal alloy powders. Spherical powder and flake of uranium metal alloys were fabricated using a centrifugal atomisation method. The nitride powders were obtained by thermal treating the metal particles under nitrogen containing gas. The phase and morphology evolutions of powders were investigated during the nitriding process. A phase analysis of nitride powders was also part of the present work. KAERI has developed the centrifugal rotating disk atomisation process to fabricate spherical uranium metal alloy powders which are used as advanced fuel materials for research reactors. The rotating disk atomisation system involves the tasks of melting, atomising, and collecting. A nozzle in the bottom of melting crucible introduces melt at the center of a spinning disk. The centrifugal force carries the melt to the edge of the disk and throws the melt off the edge. Size and shape of droplets can be controlled by changing the nozzle size, the disk diameter and disk speed independently or simultaneously. By adjusting the processing parameters of the centrifugal atomiser, a spherical and flake shape

  2. Solvolytic liquefaction of wood under mild conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.M.

    1982-04-01

    Conversion of wood to liquid products requires cleavage of bonds which crosslink the wood structure. This study examines a low-severity wood solubilization process utilizing a solvent medium consisting of a small amount of sulfuric acid and a potentially wood-derivable alcohol. In one half hour of reaction time at 250/sup 0/C under 15 psia starting nitrogen pressure, over 95% of the wood (maf) was rendered acetone-soluble. The product is a soft, black, bitumen-like solid at room temperature but readily softens at 140/sup 0/C. Between 25 and 50% of the original wood oxygen, depending on alcohol used, was removed as water. Approximately 2 to 17% of the alcohols were retained in the product. Gel permeation chromatography showed that the product's median molecular weight is around 300. Based on experimental and literature results, a mechanism for wood solubilization is proposed. This involves protonation of the etheric oxygen atoms, leading to subsequent bond scission to form carbonium ions which are stabilized by solvent alkoxylation. At severe conditions, polymerization and condensation reactions result in acetone-insoluble materials.

  3. Utilisation of Estonian energy wood resources

    Energy Technology Data Exchange (ETDEWEB)

    Muiste, P.; Tullus, H.; Uri, V. [Estonian Agricultural University, Tartu (Estonia)

    1996-12-31

    In the end of the Soviet period in the 1980s, a long-term energy programme for Estonia was worked out. The energy system was planned to be based on nuclear power and the share of domestic alternative sources of energy was low. The situation has greatly changed after the re-establishment of the Estonian independence, and now wood and peat fuels play an important role in the energy system. Energy consumption in Estonia decreased during the period 1970-1993, but this process has less influenced the consumption of domestic renewable fuels - peat and wood. It means that the share of these fuels has grown. The investment on substitution of imported fossil fuels and on conversion of boiler plants from fossil fuels to domestic fuels has reached the level of USD 100 million. The perspectives of the wood energy depend mainly on two factors; the resources and the price of wood energy compared with other fuels. The situation in wood market influences both the possible quantities and the price. It is typical that the quickly growing cost of labour power in Estonia is greatly affecting the price of energy wood. Though the price level of fuel peat and wood chips is lower than the world market price today, the conditions for using biofuels could be more favourable, if higher environmental fees were introduced. In conjunction with increasing utilisation of biofuels it is important to evaluate possible emissions or removal of greenhouse gases from Estonian forests 3 refs.

  4. Wood quality changes caused by mineral fertilization

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Sette Jr

    2014-06-01

    Full Text Available The diverse and important use of wood from fast growth eucalyptus plantations requires the analysis of the effect of mineral fertilizers on wood quality. The objective of this study was to evaluate the anatomical characteristics and wood density from Eucalyptus grandis trees (3 m x 2 m spacing fertilized with potassium and sodium (at planting, 6 th and 12th month. Fifteen (15 6 years old eucalyptus trees were selected (5 trees/treatment, cut and wood samples at DBH (1,3 m were taken for anatomical characteristics (fiber and vessels and wood density analysis. Results showed that eucalyptus trees treated with mineral fertilizers did not show significant alteration in average wood density, with radial profile model common to all three treatments, characterized by a values increase in the region next to the pith, toward to bark. Mineral fertilization influenced wood anatomical characteristics: treatment with sodium was characterized by thinner walls and lumen larger diameter; in treatment with potassium, larger vessels were detected.

  5. Utilisation of Estonian energy wood resources

    International Nuclear Information System (INIS)

    Muiste, P.; Tullus, H.; Uri, V.

    1996-01-01

    In the end of the Soviet period in the 1980s, a long-term energy programme for Estonia was worked out. The energy system was planned to be based on nuclear power and the share of domestic alternative sources of energy was low. The situation has greatly changed after the re-establishment of the Estonian independence, and now wood and peat fuels play an important role in the energy system. Energy consumption in Estonia decreased during the period 1970-1993, but this process has less influenced the consumption of domestic renewable fuels - peat and wood. It means that the share of these fuels has grown. The investment on substitution of imported fossil fuels and on conversion of boiler plants from fossil fuels to domestic fuels has reached the level of USD 100 million. The perspectives of the wood energy depend mainly on two factors; the resources and the price of wood energy compared with other fuels. The situation in wood market influences both the possible quantities and the price. It is typical that the quickly growing cost of labour power in Estonia is greatly affecting the price of energy wood. Though the price level of fuel peat and wood chips is lower than the world market price today, the conditions for using biofuels could be more favourable, if higher environmental fees were introduced. In conjunction with increasing utilisation of biofuels it is important to evaluate possible emissions or removal of greenhouse gases from Estonian forests 3 refs

  6. Wood-starved and footsore

    International Nuclear Information System (INIS)

    Field, T.

    1993-01-01

    Nearly half the people on earth soon may find themselves a little colder and a little hungrier as sources of cheap fuel for cooking and heating begin to disappear. Traditional wood-base fuels such as firewood and charcoal are becoming scarce as populations increase and forest land is converted to other uses. For more than 100 million people, this shortage has reached crisis proportions. In just seven years the world population, now estimated at 5.5 billion, is expected to exceed 6.25 billion. Almost half-including nearly 600 million urban dwellers-may not have enough fuel to heat their homes and feed their families. By 2025, when the world population could reach 10 billion, finding fuel supplies that are reliable and inexpensive will be both a rural and an urban problem. Solutions are being explored in several areas, based on more efficient and more effective tree planting and more energy efficient technologies

  7. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1993-01-01

    The Savannah River Laboratory (SRL) is developing a powder metallurgy (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U3O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼ 40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high-density P/M fuel development. The purpose of the P/M development program at SRL is to: determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, continue metal forming studies for extrusion and drawing, and evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes. Experimental results of testing the fuel assemblies performance so far indicate that: cores containing fine (-325 mesh) U 3 O 8 and aluminum powders can be made practically free of high-density areas using the outlined P/M pre blending and sieving techniques. U 3 O 8 -Al cores can be isostatically compacted with up to 100 wt U 3 O 8 and tubes successfully extruded with up to 80 wt oxide; fission gas blistering of U 3 O 8 -Al P/M tubes as indicated by the blister tests is a function of fissions/cc of U 3 O 8 in the core; Decreasing the fission density of oxide increases the threshold temperature for blister formation; U 3 O 8 -Al P/M fuel tubes with up to 59 wt U 3 O 8 have been successfully irradiated in SRP reactor to 1.6 x 10 21 fissions/cc of core or 7 x 10 20 fissions/cc of U 3 O 8 small

  8. Housing and the wood industry, trends & market conditions

    Science.gov (United States)

    Urs Buehlmann; Matt Bumgardner; Al Schuler; K. Koenig

    2011-01-01

    Housing markets continue to have major impacts on the secondary wood industry. So, what are the steps being taken by wood products manufacturers in order to stay viable? As a follow-up to last year's article, "Housing Market's Impact on the Secondary Woodworking Industry" (Wood & Wood Products, July 2010), the focus of this year's study was...

  9. Consumer preference study of characteristics of Hawaiian koa wood bowls

    Science.gov (United States)

    Eini C Lowell; Katherine Wilson; Jan Wiedenbeck; Catherine Chan; J. B. Friday; Nicole Evans

    2017-01-01

    Koa (Acacia koa A. Gray), a species endemic to the Hawaiian Islands, has ecological, cultural, and economic significance. Its wood is prized globally but today, most woodworkers only use koa wood from dead and dying old-growth trees. The general perception of wood from young-growth koa is that it lacks the color and figure of old-growth wood and is...

  10. The vessels in the wood of Javan Mangrove trees

    NARCIS (Netherlands)

    Janssonius, H.H.

    1950-01-01

    In the course of my study on the wood-anatomy of Javan woods (Mikrographie des Holzes der auf Java vorkommenden Baumarten), I examined also many woods from mangrove-trees. Mangrove has been the subject of much investigation; the community is usually described as xeromorphic. Mangrove woods proved to

  11. Utilization trend of wood species utilized in furniture industry in ...

    African Journals Online (AJOL)

    The utilization trend of four commonly used wood species and two lesser used wood species that are used for furniture making was examined. The wood species are Mansonia altissima (Mansonia), Khaya ivorensis (Khaya), Cordia millenii (Cordia) and Tectona grandis (Teak) as commonly used wood species; Aningeria ...

  12. 49 CFR 178.515 - Standards for reconstituted wood boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for reconstituted wood boxes. 178.515... wood boxes. (a) The identification code for a reconstituted wood box is 4F. (b) Construction requirements for reconstituted wood boxes are as follows: (1) The walls of boxes must be made of water...

  13. The compression of wood/thermoplastic fiber mats during consolidation

    Science.gov (United States)

    Karl R. Englund; Michael P. Wolcott; John C. Hermanson

    2004-01-01

    Secondary processing of non-woven wood and wood/thermoplastic fiber mats is generally performed using compression molding, where heated platens or dies form the final product. Although the study and use of wood-fiber composites is widespread, few research efforts have explicitly described the fundamentals of mat consolidation. In contrast, the wood composite literature...

  14. Achieving wood energy potentials: evidence in northeastern Minnesota.

    Science.gov (United States)

    Dennis P. Bradley; David C. Lothner

    1987-01-01

    A study of wood energy potential in northeastern Minnesota concludes that (1) the forests of the region could support a much larger wood energy harvest without significant cost increases for other forest products; (2) existing stands are predominantly overmature and cutting more now will enhance future wood supplies for all users; (3) converting to wood energy could...

  15. The use and market for wood in the electrometallurgical industry

    Science.gov (United States)

    Jeffery L. Wartluft; Jeffery L. Wartluft

    1971-01-01

    Wood residues, particularly large chips, play an important role in the electric smelting of certain ferro-alloys. This is a report on the characteristics and growth potential of the market for wood in the electrometallurgicaI industry, including a brief account of how wood is used in electrometallurgical processes, a discussion of the preferred form of wood used, a...

  16. Finite Element Analysis Of Boron Diffusion In Wood

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Hoffmeyer, Preben; Bechgaard, Carl

    2002-01-01

    The coupled heat and mass transfer equations for air, water and heat transfer are supplemented with a conservation equation for an additional species representing the concentration of boron in wood. Boundary conditions for wood-air. wood-soil and wood-boron interfaces arc discussed and finally...

  17. Methods for Mitigating the Environmental Risks Associated with Wood Preservatives

    Science.gov (United States)

    Dennis Hayward; Stan T. Lebow; Kenneth M. Brooks

    2011-01-01

    As noted in earlier chapters, the treatment of wood is both art and science. Wood is a variable material; treatment results tend to vary with the preservative and wood species and even within boards of the same species. This means that treated wood often contains a range of preservative retentions. Some pieces will have less than the desired retention, while others may...

  18. Raman spectroscopic characterization of wood and pulp fibers

    Science.gov (United States)

    Umesh Prasad Agarwal

    2008-01-01

    This chapter reviews applications of Raman spectroscopy in the field of wood and pulp fibers. Most of the literature examined was published between 1998 and 2006. In addition to introduction, this chapter contains sections on wood and components, mechanical pulp, chemical pulp, modified/treated wood, cellulose I crystallinity of wood fibers, and the self-absorption...

  19. Adhesives for Achieving Durable Bonds with Acetylated Wood

    Directory of Open Access Journals (Sweden)

    Charles R. Frihart

    2017-12-01

    Full Text Available Acetylation of wood imparts moisture durability, decay resistance, and dimensional stability to wood; however, making durable adhesive bonds with acetylated wood can be more difficult than with unmodified wood. The usual explanation is that the acetylated surface has fewer hydroxyl groups, resulting in a harder-to-wet surface and in fewer hydrogen bonds between wood and adhesive. This concept was evaluated using four different adhesives (resorcinol–formaldehyde, emulsion polymer isocyanate, epoxy, and melamine–formaldehyde with unmodified wood, acetylated wood, and acetylated wood that had been planed. Strikingly, acetylation did not hinder adhesive bonds with a waterborne resorcinol–formaldehyde adhesive that bonded equally well to both unmodified and acetylated yellow poplar. An epoxy adhesive bonded better to the acetylated wood than to the unmodified wood, in contrast to an emulsion polymer isocyanate, which gave less durable bonds to acetylated than to unmodified wood. Planing of the acetylated wood surface prior to bonding reduced bond durability for the epoxy adhesive and increased the amount of surface hydroxyl groups, as measured using X-ray photoelectron spectroscopic analysis of the trifluoroacetic anhydride-treated wood. These experiments showed that wood modification is useful in understanding wood-adhesive interactions, in addition to determining how to develop adhesives for acetylated woods.

  20. Factors that lead to failure with wood adhesive bonds

    Science.gov (United States)

    Charles R. Frihart; James F. Beecher

    2016-01-01

    Understanding what makes a good wood adhesive is difficult since the type of adhesive, wood species, bonding process, and resultant products vary considerably. Wood bonds are subjected to a variety of tests that reflect the different product performance criteria in diverse countries. The most common tests involve some type of moisture resistance; both wood and adhesive...

  1. Wood and Other Materials Used to Construct Nonresidential Buildings - Canada

    Science.gov (United States)

    David B. McKeever; Joe Elling

    2014-01-01

    Low-rise nonresidential building construction is an important market in Canada for lumber, engineered wood products, structural wood panels, and nonstructural wood panels. This report examines wood products consumption in 2012 for construction of selected low-rise nonresidential buildings types that have six or fewer stories. Buildings with more than six stories are...

  2. Crane harvesters for systematic wood clearing

    Energy Technology Data Exchange (ETDEWEB)

    Mahler, G.

    1988-07-30

    Wood harvesting in methodical clearing areas has witnessed developments over the last thirty years that can be described for one thing with 'Shifting from short timber to long timber' and for the other with shifting part of the work to central places. Both approaches to make harvesting of thin wood more efficient have been intensively studied over this period by Grammel. Further, thin wood harvesting has lately gained in importance in terms of operational efficiency because more recent recommendations for forest management have very substantially increased intermediate returns at least temporarily.

  3. Mathematical modelling of wood and briquettes torrefaction

    Energy Technology Data Exchange (ETDEWEB)

    Felfli, Felix Fonseca; Luengo, Carlos Alberto [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Grupo Combustiveis Alternativos; Soler, Pedro Beaton [Universidad de Oriente, Santiago de Cuba (Cuba). Fac. de Ingenieria Mecanica. Centro de Estudios de Eficiencia Energetica; Rocha, Jose Dilcio [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE)

    2004-07-01

    A mathematical model valid for the torrefaction of wood logs and biomass briquettes is presented. The model described both chemical and physical processes, which take place in a moist piece of wood heated at temperatures between 503 and 573 K. Calibration measurements of the temperature profile and mass loss, were performed on dry cylinders of wood samples during torrefaction in an inert atmosphere at 503, 533, and 553 K. The calculated data shows a good agreement with experiments. The model can be a useful tool to estimate projecting and operating parameters for torrefaction furnaces such as minimum time of torrefaction, energy consumption and the mass yield. (author)

  4. Supply of Rubber Wood Log in Malaysia

    OpenAIRE

    Noraida, A. W.; Abdul-Rahim, A. S.

    2014-01-01

    Issue on shortage of raw material for wood processing solved by discovery of rubber wood log as one of the substitutes the natural log. This paper examines the supply of rubber wood log in Malaysia. We employ ARDL Bound Approach Test and time series data from 1980 to 2010 which represented the whole Malaysia are used to achieve the established objectives. The result shown, in the long run harvested area and wages have 1% and 10% significant level respectively. While in the short run, there wa...

  5. Wood used by Stradivari and Guarneri.

    Science.gov (United States)

    Nagyvary, Joseph; DiVerdi, Joseph A; Owen, Noel L; Tolley, H Dennis

    2006-11-30

    Whether or not the great Italian violin-makers used wood that had been chemically processed in order to preserve it and enhance the instrument's sound quality has long been a contentious issue. Here we use nuclear magnetic resonance and infrared spectroscopy to analyse organic matter in wood taken from antique instruments made by Stradivari and Guarneri del Gesu. Our results indicate that the wood used by the masters could indeed have been chemically treated, a technique that may inspire an approach to violin making that is more chemistry-based.

  6. Environmental assessment of domestic wood heating

    International Nuclear Information System (INIS)

    Labouze, E.; Le Guerin, Y.

    2009-01-01

    In France, more than 6 million families are concerned with the domestic use of wood energy. The wood energy plan of ADEME aims at encouraging the development of wood energy in three sectors: domestic, collective/tertiary, industrial. In that context, ADEME commissioned BIO Intelligence Service a life cycle assessment of collective and industrial heating in order to give objective environmental information and to analyse the strength and weakness of wood heating. Three scenarios were defined according to the origin of wood: firewood, granules and sawmill chips. The study also proposes a comparison to other heating systems: gas, fuel oil and electricity. The life cycle analysis applied to domestic heating consists in quantifying the environmental impacts of the whole linked steps: extraction of fuel, distribution, final use... Every system under study has been divided according to three main stages: - Extraction of raw materials; - Transport of fuels until the place of storage or distribution; - Use (combustion or upstream production of energy in the case of electricity). The environmental impacts are estimated with the following indicators: - Non renewable primary energy balance sheet; - Global warming potential; - Air acidification potential; - Eutrophication potential; - Emissions of toxic metals in air and in soils. The results show that wood heating have the best energy and global warming balance sheets. For air acidification, the combustion stage is pre-dominant regardless of the energy resource. This is mainly due to nitrogen and sulphur oxides airborne emissions. For wood heating, preparation requires fuel consumption which also contributes significantly to nitrogen oxides emissions. The comparison with conventional energy shows that the wood scenarios are well positioned in relation to fuel and electricity for this indicator. Gas appears to be the best heating option for this indicator. The contribution eutrophication is also due to nitrogen oxides airborne

  7. Hygroscopic behavior of lyophilized acerola pulp powder

    Directory of Open Access Journals (Sweden)

    Luciana C. Ribeiro

    2016-03-01

    Full Text Available ABSTRACT Powder products are characterized by their practicality and long life. However, fruit powders have high hygroscopicity and tend to agglomerate due to its hydrophilic nature. The isotherms of equilibrium moisture content apply to the study of dehydrated food preservation potential. Acerola is a nutritionally rich fruit, with great economic and industrial potential. The objective of this study was to analyse acerola powder adsorption isotherms obtained by lyophilization and characterize the powder obtained from lyophilized acerola pulp. Analysis of hygroscopicity, solubility and degree of caking were performed. Isotherms were represented by the mathematical models of GAB, BET, Henderson and Oswin, at temperatures of 25, 35 and 45 °C. According to the results, the obtained powder showed hygroscopicity of 5.96 g of absorbed water 100g-1 of solids, solubility of 95.08% and caking of 14.12%. The BET model showed the best fit to the adsorption isotherms of the acerola pulp powder obtained by lyophilization. The obtained isotherm was of type III, with a "J" shape. There was an inversion of the effect of temperature on the isotherms of acerola powders.

  8. Electrical properties and x-ray diffraction of wood and wood plastic composite (WPC)

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M.A.; Idriss Ali, K.M. (Institute of Nuclear Science and Technology, Savar, Dacca (Bangladesh)); Wang, W. (New South Wales Univ., Kensington (Australia))

    1991-01-01

    Wood plastic composite (WPC) of kadom, simul, mango and debdaro were prepared with two monomers methylmethacrylate (MMA) and butylmethacrylate (BMA) using high energy ionizing radiation. X-ray diffraction and scanning electron microscope (SEM) studies reveal that significant grafting occurred with wood fiber. Electric properties like resistivity and dielectric constant of both wood and WPC were measured under different moisture contents and relative humidities. The resistivities of wood decreased dramatically with increase of moisture content, but those of WPC decreased very slowly with moisture content. The dielectric constant of wood increased significantly with moisture content but no significant difference was observed in the case of WPC within the range of moisture contents studied. The dielectric constants of untreated wood also increased with their densities. (author).

  9. Electrical properties and X-ray diffraction of wood and wood plastic composite (WPC)

    Science.gov (United States)

    Ahmad Khan, Mubarak; Idriss Ali, K. M.; Wang, W.

    Wood plastic composite (WPC) of kadom, simul, mango and debdaro were prepared with two monomers, methylmethacrylate (MMA) and butylmethacrylate (BMA) using high energy ionizing radiation. X-ray diffraction and scanning electron microscope (SEM) studies reveal that significant grafting occurred with wood fiber. Electric properties like resistivity and dielectric constant of both wood and WPC were measured under different moisture contents and relative humidities. The resistivities of wood decreased dramatically with increase of moisture content, but those of WPC decreased very slowly with moisture content. The dielectric constant of wood increased significantly with moisture content but no significant difference was observed in the case of WPC within the range of moisture contents studied. The dielectric constants of untreated wood also increased with their densities.

  10. Dry Powder Coating using Planetary Centrifugal Mixer.

    Science.gov (United States)

    Miyazaki, Yasunori; Miyawaki, Kaoru; Uchino, Tomonobu; Kagawa, Yoshiyuki

    2015-01-01

    Extemporaneous compounding is an important part of pharmacy practice, and should be standardized and sophisticated to ensure the quality of the compounded preparations. Recently, we applied a planetary centrifugal mixer (PCM) to powder blending, which has attracted interest for its small scale and lack of contamination. In this study, we aimed to reveal the feasibility of dry powder coating through ordered mixing of fine particles using PCM. Cohesive lactose powders (Pharmatose450M) were dry coated with magnesium stearate (MgSt) using from 0.1 to 5%(w/w) content. The operational variables tested were operation time (1-30 min), operation speed (400-1000 rpm), vessel size (24-100 mL), and charging rate in the vessel (20-40%). The processed powders were evaluated for their surface morphology, flowability, and wettability. Furthermore, fine ibuprofen particles were coated with various lubricants, and then the dissolution profiles were examined. The crystallinity of ibuprofen was assessed using FT-IR and PXRD. Lactose powders were successfully coated with MgSt using PCM. When the level of MgSt was over 1%, the surface of the lactose powders was thoroughly covered. Angles of repose were 51° and 41° for unprocessed and processed powders with 1% MgSt, respectively. The contact angle of the water drop on the 1% MgSt sample leached to be 132°, changing to a hydrophobic surface. Investigations under various operational conditions revealed that higher improvement was observed upon higher speed and longer time, and a smaller charging rate in the vessel. Vessel size had no impact. Moreover, improved dissolution of ibuprofen coated with both hydrophilic and hydrophobic lubricants was observed owing to good dispersing behavior. Besides, no alteration of crystallinity was detected. PCM is an effective tool for dry powder coating with low impact stress. The presented method will contribute a great deal to making crushed tablets a functional powder.

  11. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1978-01-01

    Fuel for Savannah River Plant (SRP) reactors consists of extruded tubes with aluminum--uranium alloy cores clad with 8001 aluminum. The 235 U in the fuel is periodically recovered and recycled in new fuel assemblies. The buildup of 236 U in the enriched uranium requires increased total uranium contents to maintain reactivity in existing assembly designs. High level waste production from these tubes is proportional to the aluminum content; therefore, appreciable radioactive waste reductions result from lower aluminum--uranium ratios and thinner clad tubes. The casting process now used for fuel cores is limited to below 40 wt % U because of the reduced fabricability of high uranium alloys. To increase tube loading and reduce aluminum, the U 3 O 8 -Al powder metallurgy (P/M) process for fuel tubes is under development. Several fabricaion and irradiaion tests have been made using production conditions. Both small scale and production tests carried out at SRL for high-density P/M fuel development are discussed

  12. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1993-01-01

    The Savannah River Laboratory (SRL) is developing a powder metallury (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U 3 O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high- density P/M fuel development. The purpose of the P/M development program at SRL is to: (1) determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, (2) irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, (3) continue metal forming studies for extrusion and drawing, and (4) evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes

  13. LCA-based optimization of wood utilization under special consideration of a cascading use of wood.

    Science.gov (United States)

    Höglmeier, Karin; Steubing, Bernhard; Weber-Blaschke, Gabriele; Richter, Klaus

    2015-04-01

    Cascading, the use of the same unit of a resource in multiple successional applications, is considered as a viable means to improve the efficiency of resource utilization and to decrease environmental impacts. Wood, as a regrowing but nevertheless limited and increasingly in demand resource, can be used in cascades, thereby increasing the potential efficiency per unit of wood. This study aims to assess the influence of cascading wood utilization on optimizing the overall environmental impact of wood utilization. By combining a material flow model of existing wood applications - both for materials provision and energy production - with an algebraic optimization tool, the effects of the use of wood in cascades can be modelled and quantified based on life cycle impact assessment results for all production processes. To identify the most efficient wood allocation, the effects of a potential substitution of non-wood products were taken into account in a part of the model runs. The considered environmental indicators were global warming potential, particulate matter formation, land occupation and an aggregated single score indicator. We found that optimizing either the overall global warming potential or the value of the single score indicator of the system leads to a simultaneous relative decrease of all other considered environmental impacts. The relative differences between the impacts of the model run with and without the possibility of a cascading use of wood were 7% for global warming potential and the single score indicator, despite cascading only influencing a small part of the overall system, namely wood panel production. Cascading led to savings of up to 14% of the annual primary wood supply of the study area. We conclude that cascading can improve the overall performance of a wood utilization system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Physical and mechanical properties of bio-composites from wood particles and liquefied wood resin

    Science.gov (United States)

    Hui Pan; Todd F. Shupe; Chung-Yun Hse

    2009-01-01

    Compression molded composites were made from wood particles and a liquefied wood/phenol/formaldehyde co-condensed resin. Based on our previous research, a phenol to wood (P/W) ratio of 2/1 was chosen for this study. The two experimental variables selected were: 1) liquefaction temperature (150o and 180oC) and 2) cooking method (atmospheric and sealed). Panels were...

  15. Powder densification maps in Selective Laser Sintering

    International Nuclear Information System (INIS)

    Bourell, D.; Wohlert, M.; Harlan, N.; Beaman, J.; Das, S.

    2002-01-01

    Selective Laser Sintering (SLS) is a manufacturing process in which a part is produced without the need for part-specific tooling. It competes effectively with other manufacturing processes when part geometry is complex and the production run is not large. Traditionally, this was limited to prototype production, although tooling applications are now appearing. This paper describes several applications of powder densification maps to advance solutions in direct SLS of metallic and ceramic powders. Time-dependent plasticity issues arise in pre-processing of powder to make it suitable for SLS and in post-processing of SLS parts to obtain desired density. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  16. Radiotreated cocoa powder for frozen elaboration

    International Nuclear Information System (INIS)

    Rodriguez Jorge, M.; Alvarez Gil, M.; Prieto Miranda, E.; Morales Valladares, M.

    1995-01-01

    The aim of the present papers is to study the possibilities of 2.0 kGy gamma radiotreated cocoa powder to be used in the elaboration of powder mixture for the preparation of chocolate frozen. Three industrial productions were carried out. Microbiological and organoleptic evaluations of the final product were performed. The results showed that the use of radurized cocoa powder in the frozen elaboration is feasible. A good hygienic quality of this product was obtained and no organoleptic alterations were detected [es

  17. Continued growth expected for wood energy despite turbulence of the economic crisis : wood energy markets, 2008-2009

    Science.gov (United States)

    Rens Hartkamp; Bengt Hillring; Warren Mabee; Olle Olsson; Kenneth Skog; Henry Spelter; Johan Vinterback; Antje Wahl

    2009-01-01

    The economic crisis has not reduced the demand for wood energy, which is expected to continue to grow. The downturn in sawmill production caused a shortage of raw material supply for wood pellet producers. With decreased demand for pulpwood-quality roundwood for wood and paper products in 2009, some pulpwood is being converted into wood energy. Economies of scale are...

  18. Juvenile wood effect in red alder : analysis of physical and mechanical data to delineate juvenile and mature wood zones

    Science.gov (United States)

    Joel W. Evans; John F. Senft; David W. Green

    2000-01-01

    The objective of this study was to investigate the influence of juvenile wood on the mechanical and physical properties of red alder. Tree growth in the first 10 to 20 years, usually referred to as juvenile wood, often influences wood quality by adversely affecting mechanical strength properties. Strength can be reduced up to 50 percent by the presence of juvenile wood...

  19. The economic potential of wood pellet production from alternative, low-value wood sources in the southeast of the US

    NARCIS (Netherlands)

    Hoefnagels, Ric; Junginger, Martin; Faaij, Andre

    2014-01-01

    The global demand for wood pellets used for energy purposes is growing. Therefore, increased amounts of wood pellets are produced from primary forestry products, such as pulp wood. The present analysis demonstrates that substantial amounts of alternative, low-value wood resources are available that

  20. On-line automatic detection of wood pellets in pneumatically conveyed wood dust flow

    Science.gov (United States)

    Sun, Duo; Yan, Yong; Carter, Robert M.; Gao, Lingjun; Qian, Xiangchen; Lu, Gang

    2014-04-01

    This paper presents a piezoelectric transducer based system for on-line automatic detection of wood pellets in wood dust flow in pneumatic conveying pipelines. The piezoelectric transducer senses non-intrusively the collisions between wood pellets and the pipe wall. Wavelet-based denoising is adopted to eliminate environmental noise and recover the collision events. Then the wood pellets are identified by sliding a time window through the denoised signal with a suitable threshold. Experiments were carried out on a laboratory test rig and on an industrial pneumatic conveying pipeline to assess the effectiveness and operability of the system.

  1. Temporal Trend in Wood Dust Exposure During the Production of Wood Pellets.

    Science.gov (United States)

    Eriksson, Kåre; Bryngelsson, Ing-Liss; Hagström, Katja

    2017-05-01

    Wood dust data collected in the production of wood pellets during 2001 to 2013 were evaluated to study a temporal trend in inhalation exposure. A linear mixed effects model of natural ln-transformed data was used to express the relative annual difference in inhalation wood dust exposure. There was an annual decrease of -20.5% of the geometric mean wood dust exposure during 2001 until 2013. The results were based on 617 inhalable dust samples collected at 14 different production units. The exposure to wood dust at the industrial premises investigated has decreased from a relatively high level of 6.4 mg m-3 in 2001 to 1.0 mg-3 in 2013. The Swedish Occupational Exposure Limit (SOEL) of 2 mg m-3 may still be exceeded. Analysis of the temporal trend in soft wood production units revealed declines in exposure of 20.5% per annum. It is important that precautions are taken to protect workers from a hazardous exposure to wood dust at the premises as the SOEL of 2 mg m-3 at some occasions is still exceeded. Additional measurements of wood dust exposure should be carried out on a regular basis in wood pellet production units in Sweden as well in other countries. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  2. Application of molecular genetic methods for identification of wood-decaying fungi in wood constructions

    Directory of Open Access Journals (Sweden)

    Elena Bobeková

    2008-01-01

    Full Text Available The aim of the paper is to evaluate the utilization of molecular biology methods for detection of wood decaying fungi directly from decomposed wood using a commercial DNA extraction kit developed for soil substrates (PowerSoil™ DNA isolation kit. The experiment based on dry rot fungus (Serpula lacrymans detection from inoculated wooden pieces under laboratory conditions was followed by field detection of wood-decaying fungi from wood structures on building constructions. Fungal DNA was identified using the PCR–based methods including species-specific PCR and sequencing of amplified ITS region of ribosomal DNA.

  3. Common wood decay fungi found in the Caribbean Basin

    Science.gov (United States)

    D. Jean. Lodge

    2016-01-01

    There are hundreds of wood-decay fungi in the Caribbean Basin, but relatively few of these are likely to grow on manmade structures built of wood or wood-composites. The wood-decay fungi of greatest concern are those that cause brown-rot, and especially brown-rot fungi that are resistant to copper-based wood preservatives. Some fungi that grow in the Caribbean and...

  4. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    OpenAIRE

    İsmail Aydın; Gürsel Çolakoğlu

    2003-01-01

    Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomic...

  5. Manufacture, delivery and marketing of wood pellets

    International Nuclear Information System (INIS)

    Huhtanen, T.

    2001-01-01

    Wood pellet is a cheap fuel, the use of which can easily bee automated. Pellet heating can be carried out with a stoker or a pellet burner, which can be mounted to oil and solid fuels boiler or to solid fuel boilers. Vapo Oy delivers wood pellet to farms and detached houses via Agrimarket stores. Vapo Oy delivers pellets to large real estates, municipalities, industry, greenhouses and power plants directly as bulk. The pellets are delivered either by trailers or lorries equipped with fan-operated unloaders. The use of wood pellets is a suitable fuel especially for real estates, the boiler output of which is 20 - 1000 kW. Vapo Oy manufactures wood pellets of cutter chips, grinding dust and sawdust. The raw material for Ilomantsi pellet plant is purchased from the province of North Karelia. The capacity of pelletizing plant is 45 000 t of pellets per year, half of which is exported mainly to Sweden and Denmark

  6. Bioinspired Wood Nanotechnology for Functional Materials.

    Science.gov (United States)

    Berglund, Lars A; Burgert, Ingo

    2018-02-22

    It is a challenging task to realize the vision of hierarchically structured nanomaterials for large-scale applications. Herein, the biomaterial wood as a large-scale biotemplate for functionalization at multiple scales is discussed, to provide an increased property range to this renewable and CO 2 -storing bioresource, which is available at low cost and in large quantities. The Progress Report reviews the emerging field of functional wood materials in view of the specific features of the structural template and novel nanotechnological approaches for the development of wood-polymer composites and wood-mineral hybrids for advanced property profiles and new functions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Wood biomass gasification in the world today

    International Nuclear Information System (INIS)

    Nikolikj, Ognjen; Perishikj, Radovan; Mikulikj, Jurica

    1999-01-01

    Today gasification technology of different kinds represents a more and more interesting option of the production of energy forms. The article describes a biomass gasification plant (waste wood) Sydkraft, Vernamo from Sweden. (Author)

  8. Wood machining highlights, 1972 and 1973

    Science.gov (United States)

    Charles W. Mcmillin

    1975-01-01

    Important wood machining research published during 1972 and 1973 is highlighted to provide the reader with a concise summary of activity in 17 fields of endeavor. The review is based on 427 references and contains 154 citations.

  9. Habitat characteristics of wintering Wood Warbler Phylloscopus ...

    African Journals Online (AJOL)

    Habitat characteristics of wintering Wood Warbler Phylloscopus sibilatrix in the Centre Region of Cameroon: conservation implications. Taku Awa II, Tsi A Evaristus, Robin C Whytock, Tsetagho Guilain, John Mallord ...

  10. Cold shock on the wood fuel industry

    International Nuclear Information System (INIS)

    Queyrel, A.

    2008-01-01

    The development of the wood fuel industry represents one of the pillars of the European energy plan, and in particular of the French energy policy, as it fulfills both objectives of development of renewable energy sources and CO 2 balance. The wood fuel industry supplies 6% of the French energy consumption and has permitted to save more than 9 million tons of petroleum equivalent. However, the conclusions of the European project CARBOSOL stress on the strong health impacts of wood-fueled combustion systems, in particular in the case of domestic individual systems and appliances. The combustion of biomass (fireplaces and agriculture) is responsible for 50 to 70% of the winter carbon pollution in Europe. The situation of collective or industrial wood-fueled facilities is different since pollution control solutions can be more easily implemented. (J.S.)

  11. Gamma radiation a help to archeological woods

    International Nuclear Information System (INIS)

    Balibar, F.

    1981-01-01

    Waterlogged archeological wood falls into dust once extracted from the water. In order to prevent this destruction several processes have been thought up. In France, the Grenoble Nuclear Study Centre has developed a method of consolidation by resin impregnation and gamma irradiation. The object is first immersed in a vessel containing liquid resin which spreads throughout the wood thereby driving off the water. During the second stage of the treatment, the impregnated objects are irradiated by gamma radiation emitted by a rectangular grid of cobalt 60, so as to polymerize the resin inside the wood. The irradiated objects are Gallo-Roman statuettes discovered during digs at the sources of the river Seine. The wood consolidated right through to the core then becomes sufficiently solid for the restorer to work on the surface of these objects [fr

  12. Understanding the Residential Wood Heater Rules

    Science.gov (United States)

    Information on the components of the current wood heater new source performance standards (NSPS) and proposed updates to the NSPS including which types of heaters are covered under the rules and the benefits.

  13. 2015 OLC Lidar DEM: Big Wood, ID

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial has collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Big Wood 2015 study area. This study area is located in...

  14. Chemistry and stoichiometry of wood liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Davis, H.G.; Kloden, D.J.; Schaleger, L.L.

    1981-06-01

    The approximate stoichiometry of liquefaction, from data of two PDU runs and a laboratory run is Wood (100 g) + CO (0.1 - 0.4 Mol) ..-->.. CO/sub 2/ (0.5 - 1.0 Mol) + H/sub 2/O (0.4 - 0.8 Mol) + Product (55 - 64 g). Product includes wood oil, water soluble organics and residues. Water is formed by decomposition, carbon dioxide by decomposition and reduction of wood oxygen by CO. Aqueous products include many carboxylic acids plus a roughly equal percentage of non-acids. The wood oil is divided into a neutral fraction and three phenolic fractions of varying molecular weight. Some specific compounds found in water and oil phases are listed.

  15. Wood ethanol and synthetic natural gas pathways

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-11-30

    This report provided details of updates to the wood ethanol pathway recently added to the GHGenius model, an analytical tool used to analyze emissions from conventional and alternative fuel combustion processes. The pathway contains data developed by the United States Department of Energy. A number of co-products were added to the wood and agricultural residue pathways, including furfural, xylitol, lignin, and glycerol. New chemical inputs included nitrogen gas, ammonia, enzymes and yeast. Biological ethanol pathways were reviewed, and separate inputs for wood, agricultural residues, corn ethanol, and wheat ethanol were added. The model was updated to reflect current research conducted on the gasification of wood and the upgrading of the gas to produce pipeline quality natural gas. New process developments in producing pipeline quality gas from coal were also added. The ability to model enzyme consumption was added to all ethanol pathways. 25 refs., 41 tabs., 8 figs.

  16. Effect of hydrothermal pretreatment on properties of bio-oil produced from fast pyrolysis of eucalyptus wood in a fluidized bed reactor.

    Science.gov (United States)

    Chang, Sheng; Zhao, Zengli; Zheng, Anqing; Li, Xiaoming; Wang, Xiaobo; Huang, Zhen; He, Fang; Li, Haibin

    2013-06-01

    Eucalyptus wood powder was first subjected to hydrothermal pretreatment in a high-pressure reactor at 160-190°C, and subsequently fast pyrolyzed in a fluidized bed reactor at 500°C to obtain high quality bio-oil. This study focused on investigating effect of hydrothermal pretreatment on bio-oil properties. Hemicellulose and some metals were effectively removed from eucalyptus wood, while cellulose content was enhanced. No significant charring and carbonization of constituents was observed during hydrothermal pretreatment. Thus pretreated eucalyptus wood gave higher bio-oil yield than original eucalyptus wood. Chemical composition of bio-oil was examined by GC/MS and (13)C NMR analyses. Bio-oil produced from pretreated eucalyptus wood exhibited lower contents of ketones and acids, while much higher levoglucosan content than bio-oil produced from original eucalyptus wood, which would help to improve thermal stability of bio-oil and extract levoglucosan from bio-oil. Hydrothermal pretreatment also improved bio-oil fuel quality through lowering water content and enhancing heating value. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Evaluating the effect of wood ultrastructural changes from mechanical treatment on kinetics of monomeric sugars and chemicals production in acid bisulfite treatment.

    Science.gov (United States)

    Liu, Yalan; Wang, Jinwu; Wolcott, Michael P

    2017-02-01

    Currently, various chemical-mechanical treatments were widely used in biofuel production to achieve high total sugar yields. However, the interaction between two treatments was scarcely investigated. In this study, we employed a ball milling process to create ultrastructural changes for Douglas-fir (Pseudotsuga menziesii) micronized wood powders. The 0, 30, and 60min ball milled wood powders resulted in a crystallinity index of 0.41, 0.21, and 0.10 respectively. It was found that the ultrastructural changes accelerate monomeric sugars production without influencing the yield of sugar degradation products. The optimal acid bisulfite treatment time was substantially decreased from 120min to 40min as the cellulose crystallinity decreased. Meanwhile, total sugar yield increased from 65% to 92% and had a linear relation with a decrease of the cellulose crystallinity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Wood decomposition as influenced by invertebrates.

    Science.gov (United States)

    Ulyshen, Michael D

    2016-02-01

    The diversity and habitat requirements of invertebrates associated with dead wood have been the subjects of hundreds of studies in recent years but we still know very little about the ecological or economic importance of these organisms. The purpose of this review is to examine whether, how and to what extent invertebrates affect wood decomposition in terrestrial ecosystems. Three broad conclusions can be reached from the available literature. First, wood decomposition is largely driven by microbial activity but invertebrates also play a significant role in both temperate and tropical environments. Primary mechanisms include enzymatic digestion (involving both endogenous enzymes and those produced by endo- and ectosymbionts), substrate alteration (tunnelling and fragmentation), biotic interactions and nitrogen fertilization (i.e. promoting nitrogen fixation by endosymbiotic and free-living bacteria). Second, the effects of individual invertebrate taxa or functional groups can be accelerative or inhibitory but the cumulative effect of the entire community is generally to accelerate wood decomposition, at least during the early stages of the process (most studies are limited to the first 2-3 years). Although methodological differences and design limitations preclude meta-analysis, studies aimed at quantifying the contributions of invertebrates to wood decomposition commonly attribute 10-20% of wood loss to these organisms. Finally, some taxa appear to be particularly influential with respect to promoting wood decomposition. These include large wood-boring beetles (Coleoptera) and termites (Termitoidae), especially fungus-farming macrotermitines. The presence or absence of these species may be more consequential than species richness and the influence of invertebrates is likely to vary biogeographically. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  19. Transparent wood for functional and structural applications

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Yang, Xuan; Berglund, Lars

    2017-12-01

    Optically transparent wood combines mechanical performance with optical functionalities is an emerging candidate for applications in smart buildings and structural optics and photonics. The present review summarizes transparent wood preparation methods, optical and mechanical performance, and functionalization routes, and discusses potential applications. The various challenges are discussed for the purpose of improved performance, scaled-up production and realization of advanced applications. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  20. Supplies and production of aircraft wood

    Science.gov (United States)

    Sparhawk, W N

    1920-01-01

    The purpose of this report is to present in brief form such information as is available regarding the supplies of the kinds of wood that have been used or seem likely to become important in the construction of airplanes, and the amount of lumber of each species normally put on the market each year. A general statement is given of the uses to which each kind of wood is or may be put.