WorldWideScience

Sample records for woods hole research

  1. Coastal Research Center Woods Hole Oceanographic Institution Report for the Period March 1986-July 1988

    Science.gov (United States)

    1989-03-01

    providing instrumentation, supplies, ship time and travel that are essential before a thesis project can be formulated. In the past we have successfully...Between Hytperiid Amphi- pods and salps Dean M. Jacobson Department/Advisor: Department of Biology/D. Anderson Degree/Date: Ph.D./February 1987...Research Center often provides partial support in the form of travel , publication or organizational expenses for symposia and workshops in Woods Hole or

  2. Woods Hole Oceanographic Institution

    Science.gov (United States)

    WHOI Instagram Instagram WHOI Vimeo Vimeo WHOI YouTube YouTube WHOI LinkedIn LinkedIn WHOI RSS Feeds our research Find a career Become a student Follow us WHOI Facebook WHOI Twitter WHOI Instagram WHOI Join our email list Follow us: WHOI Facebook WHOI Twitter WHOI Instagram WHOI YouTube WHOI LinkedIn

  3. Researcher Profile for Ocean Acidification Principal Investigator Workshop at Woods Hole Oceanograpic Institution

    Science.gov (United States)

    Research Interests: The research I conduct at EPA focuses on application of quantitative ecological methods, especially those of theoretical and experimental population ecology, in risk assessment. Much of our recent effort has focused on marine mysids because of their legacy ...

  4. The Woods Hole Partnership Education Program (PEP) (Invited)

    Science.gov (United States)

    Jearld, A.; Liles, G.; Gutierrez, B.

    2013-12-01

    In March 2009, the Woods Hole Diversity Initiative (WHDI) launched the Partnership Education Program (PEP), a multi-institutional effort to increase diversity in the student population (and ultimately the work force) in the Woods Hole science community. PEP, a summer research internship program, is open to students of all backgrounds but is designed especially to provide opportunities for individuals from populations under-represented in science, technology, engineering, and mathematics (STEM) and who otherwise would not have had the opportunity to come to Woods Hole to study or do research. A month-long course, 'Ocean and Environmental Sciences: Global Climate Change,' sets the stage for their summer research projects. The PEP model is emerging as an effective and sustainable approach to bringing students into the STEM research community. PEP is carefully structured to provide critical support for students as they complete their undergraduate experience and prepare for careers and/or graduate school. In its first five years, PEP has brought to the Woods Hole science community more than 75 students from over 50 colleges and universities, including many that do not typically send talent into marine and/or ecological research. PEP is unusual (perhaps even unique) in that it is a collaborative initiative involving seven partner institutions. Working together, the PEP collaborative has established a critical mass of under-represented students who are now in graduate school and/or working in STEM areas.

  5. Enhancing Graduate Education and Research in Ocean Sciences at the Universidad de Concepcion (UDEC) and in Chile: Cooperation Between UDEC and Woods Hole Oceanographic Institution.

    Science.gov (United States)

    Farrington, J.; Pantoja, S.

    2007-05-01

    The Woods Hole Oceanographic Institution, USA (WHOI) and the University of Concepcion, Chile (UDEC) entered into an MOU to enhance graduate education and research in ocean sciences in Chile and enhance research for understanding the Southeastern Pacific Ocean. The MOU was drafted and signed after exchange visits of faculty. The formulation of a five year program of activities included: exchange of faculty for purposes of enhancing research, teaching and advising; visits of Chilean graduate students to WHOI for several months of supplemental study and research in the area of their thesis research; participation of Chilean faculty and graduate students in WHOI faculty led cruises off Chile and Peru (with Peruvian colleagues); a postdoctoral fellowship program for Chilean ocean scientists at WHOI; and the establishment of an Austral Summer Institute of advanced undergraduate and graduate level intensive two to three week courses on diverse topics at the cutting edge of ocean science research co-sponsored by WHOI and UDEC for Chilean and South American students with faculty drawn from WHOI and other U.S. universities with ocean sciences graduate schools and departments, e.g. Scripps Institution of Oceanography, University of Delaware. The program has been evaluated by external review and received excellent comments. The success of the program has been due mainly to: (1) the cooperative attitude and enthusiasm of the faculty colleagues of both Chilean Universities (especially UDEC) and WHOI, students and postdoctoral fellows, and (2) a generous grant from the Fundacion Andes- Chile enabling these activities.

  6. Wood Protection Research Council: Research Priorities 2013

    Science.gov (United States)

    Carol A Clausen; Frederick Green III; Grant T. Kirker; Stan T. Lebow

    2014-01-01

    This report summarizes presentations and comments from the inaugural Wood Protection Research Council meeting. Research needs for the wood protection industry were identified and prioritized. Methods for successfully addressing research needs were discussed by industry, academia, and association representatives.

  7. Collections management plan for the U.S. Geological Survey Woods Hole Coastal and Marine Science Center Data Library

    Science.gov (United States)

    List, Kelleen M.; Buczkowski, Brian J.; McCarthy, Linda P.; Orton, Alice M.

    2015-08-17

    The U.S. Geological Survey Woods Hole Coastal and Marine Science Center has created a Data Library to organize, preserve, and make available the field, laboratory, and modeling data collected and processed by Woods Hole Coastal and Marine Science Center staff. This Data Library supports current research efforts by providing unique, historic datasets with accompanying metadata. The Woods Hole Coastal and Marine Science Center’s Data Library has custody of historic data and records that are still useful for research, and assists with preservation and distribution of marine science records and data in the course of scientific investigation and experimentation by researchers and staff at the science center.

  8. Uses of the Drupal CMS Collaborative Framework in the Woods Hole Scientific Community (Invited)

    Science.gov (United States)

    Maffei, A. R.; Chandler, C. L.; Work, T. T.; Shorthouse, D.; Furfey, J.; Miller, H.

    2010-12-01

    Organizations that comprise the Woods Hole scientific community (Woods Hole Oceanographic Institution, Marine Biological Laboratory, USGS Woods Hole Coastal and Marine Science Center, Woods Hole Research Center, NOAA NMFS Northeast Fisheries Science Center, SEA Education Association) have a long history of collaborative activity regarding computing, computer network and information technologies that support common, inter-disciplinary science needs. Over the past several years there has been growing interest in the use of the Drupal Content Management System (CMS) playing a variety of roles in support of research projects resident at several of these organizations. Many of these projects are part of science programs that are national and international in scope. Here we survey the current uses of Drupal within the Woods Hole scientific community and examine reasons it has been adopted. The promise of emerging semantic features in the Drupal framework is examined and projections of how pre-existing Drupal-based websites might benefit are made. Closer examination of Drupal software design exposes it as more than simply a content management system. The flexibility of its architecture; the power of its taxonomy module; the care taken in nurturing the open-source developer community that surrounds it (including organized and often well-attended code sprints); the ability to bind emerging software technologies as Drupal modules; the careful selection process used in adopting core functionality; multi-site hosting and cross-site deployment of updates and a recent trend towards development of use-case inspired Drupal distributions casts Drupal as a general-purpose application deployment framework. Recent work in the semantic arena casts Drupal as an emerging RDF framework as well. Examples of roles played by Drupal-based websites within the Woods Hole scientific community that will be discussed include: science data metadata database, organization main website, biological

  9. Archival policies and collections database for the Woods Hole Science Center's marine sediment samples

    Science.gov (United States)

    Buczkowski, Brian J.; Kelsey, Sarah A.

    2007-01-01

    The Woods Hole Science Center of the U.S. Geological Survey (USGS) has been an active member of the Woods Hole research community, Woods Hole, Massachusetts, for over 40 years. In that time there have been many projects that involved the collection of sediment samples conducted by USGS scientists and technicians for the research and study of seabed environments and processes. These samples were collected at sea or near shore and then brought back to the Woods Hole Science Center (WHSC) for analysis. While at the center, samples are stored in ambient temperature, refrigerated and freezing conditions ranging from +2º Celsius to -18º Celsius, depending on the best mode of preparation for the study being conducted or the duration of storage planned for the samples. Recently, storage methods and available storage space have become a major concern at the WHSC. The core and sediment archive program described herein has been initiated to set standards for the management, methods, and duration of sample storage. A need has arisen to maintain organizational consistency and define storage protocol. This handbook serves as a reference and guide to all parties interested in using and accessing the WHSC's sample archive and also defines all the steps necessary to construct and maintain an organized collection of geological samples. It answers many questions as to the way in which the archive functions.

  10. Increasing the Presence of Underrepresented Minorities in the Geosciences: The Woods Hole Partnership Education Program Model and Outcomes

    Science.gov (United States)

    George, A.; Gutierrez, B.; Jearld, A.; Liles, G.; Scott, O.; Harden, B.

    2017-12-01

    Launched in 2009, the Partnership Education Program (PEP) is supported by six scientific institutions in Woods Hole, Massachusetts through the Woods Hole Diversity Initiative. PEP, which was shaped by experience with other diversity programs as well as input from scientists in Woods Hole, is designed to promote a diverse scientific community by recruiting talent from minority groups that are under-represented in marine and environmental sciences. Focused on college juniors and seniors with course work in marine and/or environmental sciences, PEP is comprised of a four-week course, "Ocean and Environmental Sciences: Global Climate Change," and a six to eight week individual research project under the guidance of a research mentor. Investigators from the six science institutions serve as course faculty and research mentors. Course credit is through PEP's academic partner, the University of Maryland Eastern Shore. PEP students also participate in seminars, workshops, field trips, at-sea experiences, career development activities, and attend lectures at participating science institutions throughout the summer. Students present their research results at the end of the summer with a 15-minute public presentation. A number of PEP participants then presented their work at professional and scientific meetings, such as AGU, using the program as a gateway to graduate education and career opportunities in the marine and environmental sciences. From 2009 through 2017, 138 students from 86 colleges and universities, including many that previously had sent few or no students or faculty to Woods Hole, have participated in the program. Participating organizations are: Northeast Fisheries Science Center (NOAA Fisheries), Marine Biological Laboratory (MBL), Sea Education Association (SEA), U.S. Geological Survey (USGS), Woods Hole Oceanographic Institution (WHOI), Woods Hole Research Center (WHRC), and University of Maryland Eastern Shore (UMES) - academic partner.

  11. The Woods Hole Partnership Education Program (PEP): Broadening Participation in the Geosciences

    Science.gov (United States)

    Scott, O.; Jearld, A., Jr.; Liles, G.; Gutierrez, B.

    2015-12-01

    In March 2009, the Woods Hole Diversity Initiative launched the Partnership Education Program (PEP), a multi-institutional effort to increase diversity in the student population (and ultimately the work force) in the Woods Hole science community. PEP, a summer research internship program, is open to students of all backgrounds but is designed especially to provide opportunities for URM in science, technology, engineering, and mathematics (STEM). PEP is a 10-week program which provides intensive mentored research, a credit-bearing course and supplemental career and professional development activities. Students have opportunities to work in various research areas of geosciences. PEP is emerging as an effective and sustainable approach to bringing students into the STEM research community. PEP is carefully structured to provide critical support for students as they complete their undergraduate experience and prepare for geosciences careers and/or graduate school. The PEP experience is intended to provide students with an entry into the Woods Hole science community, one of the most vibrant marine and environmental research communities in the world. The program aims to provide a first-hand introduction to emerging issues and real-world training in the research skills that students need to advance in science, either as graduate students or bachelors-level working scientists. This is a long-recognized need and efforts are being made to ensure that the students begin to acquire skills and aptitudes that position them to take advantage of a wide range of opportunities. Of note is that the PEP is transitioning into a two year program where students are participating in a second year as a research intern or employee. Since 2013, at least four partner institutions have invited PEP alumni to participate in their respective programs as research assistants and/or full-time technicians.

  12. Archive of Geosample Data and Information from the Woods Hole Oceanographic Institution (WHOI) Seafloor Samples Laboratory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Woods Hole Oceanographic Institution (WHOI) Seafloor Samples Laboratory is a partner in the Index to Marine and Lacustrine Geological Samples (IMLGS) database,...

  13. 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...

  14. Effect of elliptic or circular holes on the stress distribution in plates of wood or plywood considered as orthotropic materials

    Science.gov (United States)

    C. B. Smith

    1944-01-01

    This is a mathematical analysis of the stress distribution existing near a hole in a wood or plywood plate subjected to tension, as, for example, near holes in the tension flanges of wood box beams. It is assumed that the strains are small and remain within the proportional limit. In this analysis a large, rectangular, orthotropic plate with a small elliptic hole at...

  15. The Woods Hole Partnership Education Program: Increasing Diversity in the Ocean and Environmental Sciences in One Influential Science Community

    Science.gov (United States)

    Jearld, A.

    2011-12-01

    To increase diversity in one influential science community, a consortium of public and private institutions created the Woods Hole Partnership Education Program, or PEP, in 2008. Participating institutions are the Marine Biological Laboratory, Northeast Fisheries Science Center of NOAA's Fisheries Service, Sea Education Association, U.S. Geological Survey, Woods Hole Oceanographic Institution, the Woods Hole Research Center, and University of Maryland Eastern Shore. Aimed at college juniors and seniors with some course work in marine and/or environmental sciences, PEP is a four-week course and a six-to-eight-week individual research project under the guidance of a research mentor. Forty-six students have participated to date. Investigators from the science institutions serve as course faculty and research mentors. We listened to experts regarding critical mass, mentoring, adequate support, network recruitment, and then built a program based on those features. Three years in we have a program that works and that has its own model for choosing applicants and for matching with mentors. We continue fine-tuning our match process, enhancing mentoring skills, preparing our students for a variety of lab cultures, and setting expectations high while remaining supportive. Our challenges now are to keep at it, using leverage instead of capacity to make a difference. Collaboration, not competition, is key since a rising tide floats all boats.

  16. 77 FR 31329 - Northeast Fisheries Science Center, Woods, Hole, MA; Public Meeting/Workshop

    Science.gov (United States)

    2012-05-25

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Northeast Fisheries Science Center, Woods, Hole, MA; Public Meeting/Workshop AGENCY: National Marine Fisheries Service (NMFS.../workshop. SUMMARY: NOAA's Northeast Fisheries Science Center will sponsor a workshop to address the stock...

  17. BIOENERGIA - Focus on wood in bioenergy research

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, D. [Jyvaeskylae Science Park, Jyvaeskylae (Finland)

    1996-12-31

    The most important area of research on wood fuel production is the development of various methods, machines and systems connected to this area, in order to produce economically competitive fuels. The integrated harvesting methods, which supply both raw material to wood products industry and wood fuel for energy production, have been chosen the main research area because they seem to be most promising. The growing amount of small-sized trees ant the need of their first thinnings have created a demand for new harvesting methods. At the moment the economical aspects restrict the harvesting of the first thinning trees either for industrial use or energy production. Research on peat production focuses on the complete use of a bog and on the development of peat production methods and machines. Development work in this area aims at decreasing production costs and also at reducing the drainage water and other elements in environmental load around the peat production sites. The use of bioenergy research will be focused on the small-scale (<20 MW{sub th},) applications. In the long term, the increase of bioenergy in heating of small houses and farms and buildings, as well as in the production of heat and power has been estimated. Research into the conversion of biomass is concentrated on the production of biomass-based liquid fuels

  18. Bioenergy Research Programme. Yearbook 1994. Production of wood fuels

    International Nuclear Information System (INIS)

    Alakangas, E.

    1995-01-01

    BIOENERGIA Research Programme is one of energy technology programmes of the Finnish Ministry of Trade and Industry (in 1995 TEKES, Technology Development Center). The aim of Bioenergy Research Programme is to increase the use of economically profitable and environmentally sound bioenergy by improving the competitiveness of present peat and wood fuels. Research and development projects will also develop new economically competitive biofuels and new equipment and methods for production, handling and using of biofuels. The funding for 1994 was nearly 50 million FIM and projects numbered 60. The main goal of the production of wood fuels research area is to develop new production methods in order to decrease the production costs to the level of imported fuels. The total potential of the wood fuel use should be at least 1.0 million toe/a (5.5 million m 3 ). There were 27 projects in 1994 for research on wood fuel production. This part of the yearbook 1994 presents the main results of these projects. The wood reserves do not limit the obtainability of the target. Research and development work has, however, directed to development of equipment and research on wood fuels production chains. Many devices, designed for both separate and integrated production of wood fuels became ready or were becoming ready for prototyping, to be used for production tests. Results of the biomass harvesting and properties research were obtained for utilization in 1994. According to the results it is possible to obtain the desired targets both in integrated and separated production of wood fuels. (author)

  19. Small scale wood combustion in Germany. Recent research and trends

    Energy Technology Data Exchange (ETDEWEB)

    Maier, H.; Unterberger, S.; Hein, K.R.G. [Institute of Process Engineering and Power Plant Technology, University of Stuttgart (Germany)

    1998-12-31

    To reduce Europe`s greenhouse gas emission CO{sub 2} it is a challenging task utilising biomass fuels as there are wood or wood residues from the forest industry. The utilisation can be done either in commercially operated medium (> 50 kWth) or full scale (> 1 MWth) decentralised heat and power stations or in small scale (< 50 kWth) domestic heating systems. In small scale heating systems untreated wood logs, wood briquette or wood pellets and in few cases wood chips are used. The present market in Germany is focused on the use of wood logs. Presently, the use of wood pellets in small scale automatically operated boilers < 15 kW especially for low energy houses is discussed more and more. Since 1980 the installation of new wood fired small scale domestic heating systems reached a significant size due to the interest of the customers to have a alternative inhouse heating system and to increase the living comfort. In 1994 the amount of sold small scale heaters in Germany were in total about 133.258 units. The thermal power of in 1994 sold units is estimated of about 1350 MW which is a significant size in total with regard to domestic heating purposes. Since few years there is a clear market trend in Germany towards the installation of open fire stoves. Due to this trend in Germany and the design characteristic of open fire stoves using huge glass doors of glass windows it is very difficult to achieve a further reduction of emissions like CO and unburned volatile hydrocarbons (VOC). In the text the requirements for modern small scale wood fired stoves in Germany as well as the actual stage and trend of research and development (R and D) are discussed 4 refs.

  20. Ocean observation data from Woods Hole Oceanographic Institution ships Oceanus, Knorr, and Atlantis, in world-wide oceans from 1993-06-26 to 2011-08-05

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are part of a collection of ocean observation data from Woods Hole Oceanographic Institution ships OCEANUS (call sign WXAQ; built 1975.00; IMO 7603617),...

  1. 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...

  2. Cleaner heat from wood. TULISIJA research programme for wood firing technology 1997-1999

    International Nuclear Information System (INIS)

    1998-01-01

    There are 1.3 million wood-burning fireplaces in Finnish homes. The interest in using fireplaces for heating of dwellings has recently been growing strongly. Some 5.6 million cubic meters of firewood is burned in domestic stoves and fireplaces annually. This corresponds to a total of 7.5 terawatthours of energy and amounts to 13 % of all energy used for heating in Finland. The aim of the TULISIJA research programme for wood firing technology (1997-1999) is to assist manufacturers in their efforts to develop the most emission-free, yet efficient, wood firing equipment in the world. Detailed objectives of the TULISIJA programme are: (1) To produce modelling capabilities for the evaluation of different fireplace designs. Capabilities are produced for utilising computer simulation for investigation of the emissions of small-size fireplaces. (2) To establish a measuring place for fireplaces, where manufacturers' equipment designs can be reliably tested according to different standards is to be built, through which the Finnish manufacturers may obtain approvals for their products for different market areas. (3) To enhance co-operation between manufacturers and research institutions. Within the programme, the expertise of researchers in universities and other research institutes is made available to manufacturers - and vice versa. Equally important is the utilisation of international co-operation and making new connections

  3. Current research in Spain on walnut for wood production

    Science.gov (United States)

    Neus Alet& #224; Neus NO-VALUE

    2004-01-01

    The Department of Mediterranean Trees at the Institut de Recerca i Tecnologia Agroalimentaries (IRTA) in Spain initiated a research program in 1993 to examine the variability among walnut species for wood production and to establish orchards with improved selections. The main objective of the programme is to obtain superior Persian walnut (Juglans regia...

  4. 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...

  5. Environmental-performance research priorities: Wood products. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-15

    This report describes a research plan to establish environmental, energy, and economic performance measures for renewable building materials, and to identify management and technology alternatives to improve environmental performance in a cost-effective manner. The research plan is designed to: (1) collect environmental and economic data on all life-cycle stages of the materials, (2) ensure that the data follows consistent definitions and collection procedures, and (3) develop analytical procedures for life-cycle analysis to address environmental performance questions. The research will be subdivided into a number of individual project modules. The five processing stages of wood used to organize the research plan are: (1) resource management and harvesting; (2) processing; (3) design and construction of structures; (4) use, maintenance, and disposal; and (5) waste recycling. Individual research module descriptions are provided in the report, as well as assessment techniques, research standards and protocol, and research management. 13 refs., 5 figs., 3 tabs.

  6. The (w)hole story : Facilitation of dead wood fauna by bark beetles?

    NARCIS (Netherlands)

    Zuo, Juan; Cornelissen, Johannes H. C.; Hefting, Mariet M.; Sass-Klaassen, Ute; van Logtestijn, Richard S. P.; van Hal, Jurgen; Goudzwaard, Leo; Liu, Jin C.; Berg, Matty P.

    Facilitation between species is thought to be a key mechanism in community assembly and diversity, as certain species create microhabitats for others. A profound characteristic of forest ecosystems is a large amount of dead wood which is colofiised by a vast array of invertebrate species. Bark

  7. The (w)hole story: Facilitation of dead wood fauna by bark beetles?

    NARCIS (Netherlands)

    Zuo, J.; Cornelissen, J.H.C.; Hefting, M.M.; Sass-Klaassen, U.; van Logtestijn, R.S.P; van Hal, J.R.; Goudzwaard, L.; Liu, J.C.; Berg, M.P.

    2016-01-01

    Facilitation between species is thought to be a key mechanism in community assembly and diversity, as certain species create microhabitats for others. A profound characteristic of forest ecosystems is a large amount of dead wood which is colonised by a vast array of invertebrate species. Bark

  8. The Black Hole of Education Research.

    Science.gov (United States)

    Miller, D. W.

    1999-01-01

    Critics feel education scholarship lacks rigor and a practical focus on achievement, wasting substantial resources. Research on effectiveness of educational reforms is often weak, inconclusive, or simply inadequate, and good scholarship may have little influence on classroom practice. Popular policies often persist despite strong research evidence…

  9. Black Holes Lead Galaxy Growth, New Research Shows

    Science.gov (United States)

    2009-01-01

    Astronomers may have solved a cosmic chicken-and-egg problem -- the question of which formed first in the early Universe -- galaxies or the supermassive black holes seen at their cores. "It looks like the black holes came first. The evidence is piling up," said Chris Carilli, of the National Radio Astronomy Observatory (NRAO). Carilli outlined the conclusions from recent research done by an international team studying conditions in the first billion years of the Universe's history in a lecture presented to the American Astronomical Society's meeting in Long Beach, California. Gas in Distant Galaxy VLA image (right) of gas in young galaxy seen as it was when the Universe was only 870 million years old. CREDIT: NRAO/AUI/NSF, SDSS Full-size JPEG, 323 KB PDF file, 180 KB Galaxy image, no annotation, JPEG 21 KB Earlier studies of galaxies and their central black holes in the nearby Universe revealed an intriguing linkage between the masses of the black holes and of the central "bulges" of stars and gas in the galaxies. The ratio of the black hole and the bulge mass is nearly the same for a wide range of galactic sizes and ages. For central black holes from a few million to many billions of times the mass of our Sun, the black hole's mass is about one one-thousandth of the mass of the surrounding galactic bulge. "This constant ratio indicates that the black hole and the bulge affect each others' growth in some sort of interactive relationship," said Dominik Riechers, of Caltech. "The big question has been whether one grows before the other or if they grow together, maintaining their mass ratio throughout the entire process." In the past few years, scientists have used the National Science Foundation's Very Large Array radio telescope and the Plateau de Bure Interferometer in France to peer far back in the 13.7 billion-year history of the Universe, to the dawn of the first galaxies. "We finally have been able to measure black-hole and bulge masses in several galaxies seen

  10. Wood chips procurement and research project at the Mikkeli region

    International Nuclear Information System (INIS)

    Saksa, T.; Auvinen, P.

    1996-01-01

    In 1993-94, a large-scale energywood production chain started as a co-operation project by the Mikkeli city forest office and local forestry societies. In 1995 over 115 000 m 3 (about 85 000 MWh of energy) of wood chips were delivered to Pursiala heat and power plant in Mikkeli. About 75 % of these chips was forest processed chips. About 70 % of the forest processed chips was whole tree chips from improvement cuttings of young forest stands and the rest was logging waste chips from regeneration cutting areas. The average total delivery costs of forest processed chips after reduction of energywood and other subsidies were approximately 45 FIM/m 3 (60 FIM/MWh) for the whole tree chips and 38 FIM/m 3 (50 FIM/MWh) for logging waste chips. The delivery costs of forest processed chips could meet the target of Bioenergy Research Programme (45 FIM/MWh) only in the most favourable cases. In an average the delivery costs were about 9 FIM/MWh more than the price obtained when sold to the heat and power plant. However the wood chip production created 27 new jobs and the increase of income to the local economy was about 2.2 milj. FIM /year. The local communities got new tax revenue about 3 FIM/MWh. The gain for the forestry was approximated to be 5 - 6 FIM/MWh. The resources of forest processed chips were studied on the basis of stand measurements. According to the study the most remarkable energywood resources were in young thinning stands on Oxalis-Myrtillus and Myrtillus forest site types. On Oxalis-Myrtillus type almost every and on Myrtillus type every second stand included energywood more than 40 m 3 /ha

  11. Physical trajectory profile data from glider sp010 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-04-09 to 2015-06-25 (NCEI Accession 0139261)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  12. Physical trajectory profile data from glider sp010 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2017-07-07 to 2017-09-12 (NCEI Accession 0166618)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution. (This deployment supported by NOAA.) The National Centers for Environmental Information (NCEI)...

  13. Physical trajectory profile data from glider sp065 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-10-01 to 2016-01-07 (NCEI Accession 0145716)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  14. Physical trajectory profile data from glider sp066 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-12-17 to 2016-04-06 (NCEI Accession 0153789)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  15. Physical trajectory profile data from glider sp055 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-07-16 to 2015-10-16 (NCEI Accession 0145714)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  16. Physical trajectory profile data from glider sp066 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2016-08-18 to 2016-09-28 (NCEI Accession 0156697)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  17. Physical trajectory profile data from glider sp007 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2017-04-27 to 2017-08-21 (NCEI Accession 0165175)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution. (This deployment supported by NOAA.) The National Centers for Environmental Information (NCEI)...

  18. Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository is a partner in the...

  19. Physical trajectory profile data from glider sp066 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2017-04-16 to 2017-08-02 (NCEI Accession 0164674)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution. (This deployment supported by NOAA.) The National Centers for Environmental Information (NCEI)...

  20. Testing painted wood : past practices at the Forest Products Laboratory and recommendations for future research

    Science.gov (United States)

    R. Sam Williams

    2009-01-01

    A brief history of paint research at the Forest Products Laboratory (FPL) in Madison, Wisconsin, sets the stage for a discussion of testing paint on wood and wood products. Tests include laboratory and outdoor tests, and I discuss them in terms of several degradation mechanisms (loss of gloss and fading, mildew growth, extractives bleed, and cracking, flaking, and...

  1. Research Concerning the Shearing Strength of Black Locust Wood

    Directory of Open Access Journals (Sweden)

    Mihaela POROJAN

    2011-06-01

    Full Text Available The paper presents the experimental resultsobtained for the shearing strength of black locustwood (Robinia pseudacacia L. harvested from twogeographical areas (North and South of Romania.Wood is subjected to shearing stress when usedwithin different fields, and especially inconstructions. Tangential stresses are produced inthe shearing sections and they are influenced by thestructure of wood through the position of theshearing plane and of the force direction towards thegrain. Accordingly, several shearing types arepossible. The shearing strengths for the three mainshearing types, both on radial and tangentialdirection were determined within the present study.The evaluation of data was achieved by using theANOVA analysis, in order to test the level ofsignificance depending on the shearing planeorientation and the harvesting area. The obtainedresults were compared to the values mentionedwithin reference literature for this wood species andtwo other hardwood species with similar density. It isworth to be mentioned that the shearing strengths ofblack locust wood from Romania (both from Northand South are generally higher than those indicatedby reference literature for oak and beech. Thisrecommends black locust wood as constructionwood and for other applications where wood issubjected to shearing stress.

  2. Bioenergy Research Programme, Yearbook 1995. Production of wood fuels; Bioenergian tutkimusohjelma, vuosikirja 1995. Puupolttoaineen tuotantotekniikka

    Energy Technology Data Exchange (ETDEWEB)

    Alakangas, E. [ed.

    1996-12-31

    Bioenergy Research Programme is one of the energy technology research programmes of the Technology Development Center TEKES. The aim of the Bioenergy Research Programme is to increase, by using technical research and development, the economically profitable and environmentally sound utilisation of bioenergy, to improve the competitiveness of present peat and wood fuels, and to develop new competitive fuels and equipment related to bioenergy. The funding for 1995 was nearly 52 million FIM and the number of projects 66. The main goal of the wood fuels research area is to develop new production methods in order to decrease the production costs to the level of imported fuels. The total potential of the wood fuel use should be at least 1.0 million toe/a (5.5 million m{sup 3}). During the year 1995 There were over 30 projects concerning the production of wood derived fuels going on. Nearly half of them focused on integrated production of pulp wood and wood fuel. About ten projects was carried out to promote the wood fuel production from logging residues. Other topics were firewood production, production logistics and wood fuel resources. For production of fuel chips from logging residues, a new chipper truck, MOHA-SISU, was introduced. The new machine gives a new logistic solution resulting in high productivity and reasonable operating costs. In Mikkeli region three years of active work promoted the usage of wood fuel in a district power plant to the level of over 110 000 m{sup 3} of fuel chips. The production costs tend to be a little high in average, and the production chain still needs to be improved

  3. Bioenergy Research Programme, Yearbook 1995. Production of wood fuels; Bioenergian tutkimusohjelma, vuosikirja 1995. Puupolttoaineen tuotantotekniikka

    Energy Technology Data Exchange (ETDEWEB)

    Alakangas, E [ed.

    1997-12-31

    Bioenergy Research Programme is one of the energy technology research programmes of the Technology Development Center TEKES. The aim of the Bioenergy Research Programme is to increase, by using technical research and development, the economically profitable and environmentally sound utilisation of bioenergy, to improve the competitiveness of present peat and wood fuels, and to develop new competitive fuels and equipment related to bioenergy. The funding for 1995 was nearly 52 million FIM and the number of projects 66. The main goal of the wood fuels research area is to develop new production methods in order to decrease the production costs to the level of imported fuels. The total potential of the wood fuel use should be at least 1.0 million toe/a (5.5 million m{sup 3}). During the year 1995 There were over 30 projects concerning the production of wood derived fuels going on. Nearly half of them focused on integrated production of pulp wood and wood fuel. About ten projects was carried out to promote the wood fuel production from logging residues. Other topics were firewood production, production logistics and wood fuel resources. For production of fuel chips from logging residues, a new chipper truck, MOHA-SISU, was introduced. The new machine gives a new logistic solution resulting in high productivity and reasonable operating costs. In Mikkeli region three years of active work promoted the usage of wood fuel in a district power plant to the level of over 110 000 m{sup 3} of fuel chips. The production costs tend to be a little high in average, and the production chain still needs to be improved

  4. A comprehensive mission to planet Earth: Woods Hole Space Science and Applications Advisory Committee Planning Workshop

    Science.gov (United States)

    1991-01-01

    The NASA program Mission to Planet Earth (MTPE) is described in this set of visuals presented in Massachusetts on July 29, 1991. The problem presented in this document is that the earth system is changing and that human activity accelerates the rate of change resulting in increased greenhouse gases, decreasing levels of stratospheric ozone, acid rain, deforestation, decreasing biodiversity, and overpopulation. Various national and international organizations are coordinating global change research. The complementary space observations for this activity are sun-synchronous polar orbits, low-inclination, low altitude orbits, geostationary orbits, and ground measurements. The Geostationary Earth Observatory is the major proposed mission of MTPE. Other proposed missions are EOS Synthetic Aperture Radar, ARISTOTELES Magnetic Field Experiment, and the Global Topography Mission. Use of the NASA DC-8 aircraft is outlined as carrying out the Airborne Science and Applications Program. Approved Earth Probes Program include the Total Ozone Mapping Spectrometer (TOMS). Other packages for earth observation are described.

  5. Advances in the study of mechanical properties and constitutive law in the field of wood research

    Science.gov (United States)

    Zhao, S.; Zhao, J. X.; Han, G. Z.

    2016-07-01

    This paper presents an overview of mechanical properties and constitutive law for wood. Current research on the mechanical properties of wood have mostly focused on density, grain, moisture, and other natural factors. It has been established that high density, dense grain, and high moisture lead to higher strength. In most literature, wood has been regarded as an anisotropic material because of its fiber. A microscopic view is used in research of wood today, in this way, which has allowed for clear observation of anisotropy. In general, wood has higher strength under a dynamic load, and no densification. The constitutive model is the basis of numerical analysis. An anisotropic model of porous and composite materials has been used for wood, but results were poor, and new constitutions have been introduced. According to the literature, there is no single theory that is widely accepted for the dynamic load. Research has shown that grain and moisture are key factors in wood strength, but there has not been enough study on dynamic loads so far. Hill law has been the most common method of simulation. Models that consider high strain rate are attracting more and more attention.

  6. Wood chip delivery and research project at Mikkeli region

    International Nuclear Information System (INIS)

    Saksa, T.; Auvinen, P.

    1995-01-01

    In 1994, a large-scale energywood production chain was started as a co-operation project by the Mikkeli city forest office and local forestry societies. Over 60 000 m 3 (about 46 000 MWh of energy) of forest processed chips were delivered to Pursiala heat and power plant in Mikkeli. About 60 % of these chips was whole tree chips from improvement cuttings of young forest stands and the rest was logging waste chips from regeneration cutting areas. The average total delivery costs of forest processed chips after reduction of energywood and other subsidies were approximately 51 FIM/m 3 (68 FIM/MWh) for the whole tree chips and 40 FIM/m 3 (53 FIM/MWh) for logging waste chips. The delivery costs of wood chips could compete with those of fuel peat only in the most favourable cases. The resources of forest processed chips were studied on the basis of forestry plans. According to the study, there is enough raw material for permanent, large-scale delivery of forest processed chips (up to 250 000 m 3 /a) in the forests located at a distance of under 40 road kilometers from the Pursiala heat and power plant. The following project stages will involve further development of the wood chip delivery chain logistics, as well as improvement of logging and chipping equipment and methods in energywood and logging waste production. Also the effects of wood energy production on the economy and environment of the whole Mikkeli region will be studied. (author)

  7. Yearbook 1998. TULISIJA Research Programme for Wood Firing Technology; Vuosikirja - Aarsbok 1997. TULISIJA

    Energy Technology Data Exchange (ETDEWEB)

    Ljung, M.; Kilpinen, P. [eds.

    1999-11-01

    TULISIJA is the 3-year national research programme for small scale wood firing technology with the aim to assist manufacturers in their efforts to develop the most emission-free, yet efficient, wood firing equipment in the world. The following ten projects have been in progress during the year 1998: The behaviour of fuel; Computational fluid dynamics simulation of combustion in small scale wood ovens; computational fluid dynamics simulation of combustion in small scale wood ovens and modelling of emission chemistry; Modelling of heat transfer in fireplace walls and constructions; Detailed emission and temperature measurements in the TULISIJA test oven; Measurement environment for fireplace testing; Reduction of emissions from soapstone fireplaces; Development of a new modular method for fireplace manufacture; Replacement of energy intensive raw material with recycled industrial waste and further development of combustion processes in fireplaces and Instructions for dimensioning and design of fireplaces for optimum living atmosphere in residences

  8. Wood residue production and utilization research at Virgina Tech

    Energy Technology Data Exchange (ETDEWEB)

    Grace, L.A.; Stuart, W.B.; Sharp, J.C. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (US)); Yu Jian-guo (Northeastern Forestry Univ., Harbin (CN))

    1988-01-01

    This paper describes the activities in crushing, drying and segregating wood residues currently underway at Virginia Tech. Experiments with high speed roll crushing as a means of reducing logging residues and small diameter stems to a form suitable for transportation and further processing appear promising. Deflecting whole tree chip streams across a double set of screens coupled with stripping transport air has been shown to reduce bark content and remove fines, bark and grit. Testing and refinement of two prototype sawdust driers is currently under way. Both driers offer increased opportunity for suspension burning and transport. (4 refs., 3 tabs., 3 figs.) (au).

  9. Bioenergy research programme. Yearbook 1996. Production of wood fuels; Bioenergian tutkimusohjelma. Vuosikirja 1996. Puupolttoaineiden tuotantotekniikka

    Energy Technology Data Exchange (ETDEWEB)

    Nikku, P [ed.

    1997-12-01

    The aim of the programme is to increase the use of economically profitable and environmentally sound bioenergy by improving the competitiveness of present peat and wood fuels. Research and development projects will also develop new economically competitive biofuels, new equipment and methods for production, handling and utilisation of biofuels. The total funding for 1996 was 27.3 million FIM and the number of projects 63. The number of projects concerning wood fuels production was 36. The main goals of the research are to develop new production methods for wood fuels in order to decrease the production costs to the level of imported fuels (100 km distance). The second goal is to decrease the small scale production costs by 20 % as compared with the 1992 technology level. Also, new harvesting technology and new work methods will be developed for forest owners and small-entrepreneurs in the course of the programme. Results of the projects carried out in 1996 in this programme are presented in this publication. The integrated harvesting methods, which supply both raw material to wood products industry and wood fuel for energy production, have been chosen the main research areas because they seem to be most promising. Most of the projects are focused in the wood fuel production from first thinnings and from final fellings. The projects broadly covered the research area focusing from material flows, productivity studies, basic wood properties to several case studies. The follow up project of Evaluation-drum chipper was completed with good fuel quality and productivity results. Also the large Forest Energy Project of Central Finland was completed. The project was a significant technology transfer and information dissemination project. (orig.)

  10. Production of wood derived fuels. Review of research projects; Puupolttoaineiden tuotantotekniikka. Tutkimusalueen katsaus

    Energy Technology Data Exchange (ETDEWEB)

    Korpilahti, A [Metsaeteho Oy, Helsinki (Finland)

    1997-12-01

    The research and development work was very active on the area of wood derived fuels during the past year 1996. Totally some 40 projects were going on, and till the end of the year about 15 projects were completed. The projects broadly covered the research area focusing from material flows, productivity studies, basic wood properties to several case studies. When new production methods and machinery was introduced earlier by demonstration projects, now they were investigated by follow up projects. The economical and quality results of logging residue harvesting and comminution seem quite satisfactory, but integrated methods and production chains still need research and development. (orig.)

  11. An extension of the Plant Ontology project supporting wood anatomy and development research

    NARCIS (Netherlands)

    Lens, F.; Cooper, L.; Gandolfo, M.A.; Groover, A.; Jaiswal, P.; Lachenbruch, B.; Spicer, R.; Staton, M.E.; Stevenson, D.W.; Walls, R.L.; Wegrzyn, J.

    2012-01-01

    The Wood Ontology project will provide a structured vocabulary and database resource that will be valuable for all scientists, including the IAWA community. To maximizethe utility of the resource and analyses it empowers, it is important for researchers to adopt the use of the ontology terms in the

  12. Forest Products Laboratory : supporting the nation's armed forces with valuable wood research for 90 years

    Science.gov (United States)

    Christopher D. Risbrudt; Robert J. Ross; Julie J. Blankenburg; Charles A. Nelson

    2007-01-01

    Founded in 1910 by the U.S. Forest Service to serve as a centralized, national wood research laboratory, the USDA Forest Products Laboratory (FPL) has a long history of providing technical services to other government agencies, including those within the Defense (DoD). A recent search of FPL’s library and correspondence files revealed that approximately 10,000...

  13. Black holes

    OpenAIRE

    Brügmann, B.; Ghez, A. M.; Greiner, J.

    2001-01-01

    Recent progress in black hole research is illustrated by three examples. We discuss the observational challenges that were met to show that a supermassive black hole exists at the center of our galaxy. Stellar-size black holes have been studied in x-ray binaries and microquasars. Finally, numerical simulations have become possible for the merger of black hole binaries.

  14. Nondestructive testing and evaluation of wood : a worldwide research update

    Science.gov (United States)

    Brian K. Brashaw; Voichita Bucur; Ferenc Divos; Raquel Goncalves; Jianxiong Lu; Roger Meder; Roy F. Pellerin; Simon Potter; Robert J Ross; Xiping Wang; Yafang. Yin

    2009-01-01

    The international forest products research community is responding to these driving forces by conducting NDT/NDE research to provide the technologies needed to address these challenges. This article presents a sample of the on-going NDT/NDE research efforts being conducted in several areas of the world.

  15. Black hole astrophysics

    International Nuclear Information System (INIS)

    Blandford, R.D.; Thorne, K.S.

    1979-01-01

    Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

  16. EXPERIMENTAL RESEARCH CONCERNING THE OPTIMAL DIMENSIONS OF AN ELASTIC STRUCTURE OF BEECH WOOD PARQUET

    Directory of Open Access Journals (Sweden)

    Olimpia-Minerva ȚURCAȘ (DIACONU

    2015-12-01

    Full Text Available This paper presents the results of the experimental research concerning the modulus of elasticity and the average value of the bending strength in case of beech (Fagus sylvatica L. wood. The investigations were performed according to SR EN 408-2004. The results of the research have been analysed in order to establish the variable parameters to be considered for the final experimental research focused on beech wood floor structures that meet the necessary requirements for the sports halls applications. The research presented in the paper is a part of the study theme of the Ph. D. thesis, which investigates the flooring structures able to support the requirements of sports halls activities, different from one sport to another.

  17. Corrosion of Embedded Metals in Wood: An Overview of Recent Research with Implications for building moisture design

    Science.gov (United States)

    Samuel L. Zelinka

    2013-01-01

    ASHRAE Standard 160, Criteria for Moisture-Control Design Analysis in Buildings, specifies moisture design criteria in buildings to prevent moisture damage such as fungal activity and corrosion. While there has been much research on mold and decay fungi in wood buildings, it is often overlooked that wet wood is corrosive to the metal screws...

  18. International evaluation of Swedish research projects on the environmental impacts of wood fuel harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, M [Inst. of Terrestrial Ecology, Grange-over-Sands (United Kingdom); Kellomaeki, S [Joensuu Univ. (Finland). Dept. of Forestry; Larsen, J B [Royal Veterinary Univ., Fredriksberg (Denmark). Dept. of Economics and Natural Resources

    1996-12-31

    The purpose of this evaluation was to inform NUTEK of the scientific quality of the research projects, as seen in an international context. The projects were therefore the main elements considered in the evaluation. The main basis of the evaluation was the scientific quality of the research and its relevance to NUTEK`s aims in the application of industrial research and development. The present report is based on the information contained in the written reports submitted by the grant holders, site visits and discussions between the grant holders and the Committee. The report first gives an overview and general recommendations concerning the overall programme on the Environmental Impacts of Wood Fuel Harvest. Thereafter, the projects are evaluated separately. The Committee was unanimous in its conclusions. Evaluated projects: Whole tree harvesting effects on forest soil; Whole tree utilization - forest yield; Nature conservation/Forest energy; Utilizing hardwoods from first thinnings of spruce as fuel wood

  19. International evaluation of Swedish research projects on the environmental impacts of wood fuel harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, M. [Inst. of Terrestrial Ecology, Grange-over-Sands (United Kingdom); Kellomaeki, S. [Joensuu Univ. (Finland). Dept. of Forestry; Larsen, J.B. [Royal Veterinary Univ., Fredriksberg (Denmark). Dept. of Economics and Natural Resources

    1995-12-31

    The purpose of this evaluation was to inform NUTEK of the scientific quality of the research projects, as seen in an international context. The projects were therefore the main elements considered in the evaluation. The main basis of the evaluation was the scientific quality of the research and its relevance to NUTEK`s aims in the application of industrial research and development. The present report is based on the information contained in the written reports submitted by the grant holders, site visits and discussions between the grant holders and the Committee. The report first gives an overview and general recommendations concerning the overall programme on the Environmental Impacts of Wood Fuel Harvest. Thereafter, the projects are evaluated separately. The Committee was unanimous in its conclusions. Evaluated projects: Whole tree harvesting effects on forest soil; Whole tree utilization - forest yield; Nature conservation/Forest energy; Utilizing hardwoods from first thinnings of spruce as fuel wood

  20. International evaluation of Swedish research projects on the environmental impacts of wood fuel harvesting

    International Nuclear Information System (INIS)

    Hornung, M.; Kellomaeki, S.; Larsen, J.B.

    1995-01-01

    The purpose of this evaluation was to inform NUTEK of the scientific quality of the research projects, as seen in an international context. The projects were therefore the main elements considered in the evaluation. The main basis of the evaluation was the scientific quality of the research and its relevance to NUTEK's aims in the application of industrial research and development. The present report is based on the information contained in the written reports submitted by the grant holders, site visits and discussions between the grant holders and the Committee. The report first gives an overview and general recommendations concerning the overall programme on the Environmental Impacts of Wood Fuel Harvest. Thereafter, the projects are evaluated separately. The Committee was unanimous in its conclusions. Evaluated projects: Whole tree harvesting effects on forest soil; Whole tree utilization - forest yield; Nature conservation/Forest energy; Utilizing hardwoods from first thinnings of spruce as fuel wood

  1. Wood-Boring Gribbles Intrigue Researchers | News | NREL

    Science.gov (United States)

    Water The researchers' tests of Cel7B found that it remained active at more than six times the salt . This organ is where gribbles make their own enzymes. In other words, they don't rely, as termites, cows from an important family of cellulases (specifically Family 7 cellulases), that are usually found in

  2. Wood : adhesives

    Science.gov (United States)

    A.H. Conner

    2001-01-01

    This chapter on wood adhesives includes: 1) Classification of wood adhesives 2) Thermosetting wood adhesives 3) Thermoplastic adhesives, 4) Wood adhesives based on natural sources 5) Nonconventional bonding of wood 6) Wood bonding.

  3. Rural Fuel-wood and Poles Research Project in Malawi: a general account

    Energy Technology Data Exchange (ETDEWEB)

    Nkaonja, R S.W.

    1981-01-01

    The Rural Fuel-wood and Poles Research Project was initiated to provide information about afforestation in the dry silvicultural zones. Plantation forestry in Malawi has concentrated on production of timber, poles, and pulpwood. It is estimated that 90% of Malawi's population of 5.5 million live in rural communities, and that the purely domestic wood requirement is 4.05 cubic m per family (of five) annually. In addition, wood is required for agricultural purposes such as tobacco curing. The remaining indigenous forest cannot meet the demand. There is an urgent need for plantations. Rather than simply planting trees, the aim is to make local communities self-sufficient in forest products. In view of the shortage of land, great emphasis is placed on trying species which have many end-uses-- e.g., poles, fuel-wood, mulch, fodder, and shade--and those which can be grown together with farm crops, a concept known as ''agroforestry.'' Over 20 ha of trials were established at locations in the three regions of the country. Acacia albida allows maize and other farm crops to grow under it, provides good shade and fodder, and--as legume--enriches the soil with nitrogen. Eucalypts were included because most produce straight poles for construction, are drought-hardy, and are rated higher than Gmelina arborea in calorific value, durability, and strength. Another tree favored for its multiple uses is Leucaena leucocephala (Hawaiian giant), but it appears that there is considerable mixture of varieties in the seeds. With the exception of one trial at Bwanje, trials have not included farm crops, but the agroforestry element will be a very important consideration in future trials.

  4. A new metric method-improved structural holes researches on software networks

    Science.gov (United States)

    Li, Bo; Zhao, Hai; Cai, Wei; Li, Dazhou; Li, Hui

    2013-03-01

    The scale software systems quickly increase with the rapid development of software technologies. Hence, how to understand, measure, manage and control software structure is a great challenge for software engineering. there are also many researches on software networks metrics: C&K, MOOD, McCabe and etc, the aim of this paper is to propose a new and better method to metric software networks. The metric method structural holes are firstly introduced to in this paper, which can not directly be applied as a result of modular characteristics on software network. Hence, structural holes is redefined in this paper and improved, calculation process and results are described in detail. The results shows that the new method can better reflect bridge role of vertexes on software network and there is a significant correlation between degree and improved structural holes. At last, a hydropower simulation system is taken as an example to show validity of the new metric method.

  5. Evaluation of wood species and preservatives for Wisconsin transportation sign posts : [research brief].

    Science.gov (United States)

    2013-12-01

    The Wisconsin Department of Transportation (WisDOT) administers approximately 11,800 miles of state highways. It uses preservative-treated wood posts for much of the signage along these highways because wood is relatively inexpensive, easy to install...

  6. Recycling of wood products. Final report of the preliminary study project partly financed by the Finnish Wood Research Oy; Puutuotteiden kierraetys. Finnish Wood Research Oy:n osarahoittaman esiselvityshankkeen loppuraportti

    Energy Technology Data Exchange (ETDEWEB)

    Pirhonen, I.; Heraejaervi, H.; Saukkola, P.; Raety, T.; Verkasalo, E., Email: henrik.herajarvi@metla.fi

    2011-07-01

    The objective of this preliminary study was to clarify the present state of recycling of wood in Finland and Europe. In the work the control measures of recycling were examined. In Finland there will be a total amount of 850 000 tons of waste wood per year. Of this amount 670 000 tons is from construction and demolishing of buildings. Burning the wood to energy is technically and economically the most reasonable use of waste wood in Finland and in several other European countries where there is a long heating season. A lot of work has been done to find new ways of utilization. The objective of the European Union to increase the use of renewable natural resources in the energy production creates an additional demand to all kinds of wood, including waste wood. The waste legislation of Finland and EU is directing to recycling, not restricting it. Furthermore, the systems to try to create markets for products containing recycled materials are under development. In the future it is expected that the legislation is tightening and the burning of waste wood is no longer calculated as acceptable recycling. Other ways to utilize wood waste should then already be developed. Furthermore, the development and introduction of new recycling methods are of important significance also when marketing wood and wood products. The recycling should be taken into consideration already at the planning stage of the building

  7. A synthesis of research on wood products and greenhouse gas impacts

    International Nuclear Information System (INIS)

    Sathre, R.; O'Connor, J.

    2008-11-01

    Existing scientific literature on the wood products industry was reviewed in an effort to summarize consensus findings, or range of findings, addressing the net life cycle greenhouse gas footprint of wood construction products. The report sought to clarify whether actively managing forests for wood production was better, worse or neutral for climate change than leaving the forest in its natural state. In addition, it sought to quantify the greenhouse gas emissions avoided per unit of wood substituted for non-wood materials. Forty-eight international studies were examined in terms of fossil energy used in wood manufacturing and compared alternatives, such as the avoidance of industrial process carbon emissions as with cement manufacturing; the storage of carbon in forests and forest products; the use of wood by-products as a biofuel replacement for fossil fuels; and carbon storage and emission due to forest products in landfills. The report presented a list of studies reviewed and individual summaries of study findings. A meta-analysis of displacement factors of wood product use was also presented. It was concluded from all of the studies reviewed, that the production of wood-based materials and products results in less greenhouse gas emission than the production of functionally comparable non-wood materials and products. 48 refs., 1 tab.

  8. 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....

  9. Wood chips procurement and research project at the Mikkeli region; Puuhakkeen hankinta- ja tutkimusprojekti Mikkelin seudulla

    Energy Technology Data Exchange (ETDEWEB)

    Saksa, T. [Finnish Forest Research Inst., Suonenjoki (Finland). Suonenjoki Research Station; Auvinen, P. [Mikkeli city (Finland). Dept. of Agriculture and Forestry

    1996-12-31

    In 1993-94, a large-scale energywood production chain started as a co-operation project by the Mikkeli city forest office and local forestry societies. In 1995 over 115 000 m{sup 3} (about 85 000 MWh of energy) of wood chips were delivered to Pursiala heat and power plant in Mikkeli. About 75 % of these chips was forest processed chips. About 70 % of the forest processed chips was whole tree chips from improvement cuttings of young forest stands and the rest was logging waste chips from regeneration cutting areas. The average total delivery costs of forest processed chips after reduction of energywood and other subsidies were approximately 45 FIM/m{sup 3} (60 FIM/MWh) for the whole tree chips and 38 FIM/m{sup 3} (50 FIM/MWh) for logging waste chips. The delivery costs of forest processed chips could meet the target of Bioenergy Research Programme (45 FIM/MWh) only in the most favourable cases. In an average the delivery costs were about 9 FIM/MWh more than the price obtained when sold to the heat and power plant. However the wood chip production created 27 new jobs and the increase of income to the local economy was about 2.2 milj. FIM /year. The local communities got new tax revenue about 3 FIM/MWh. The gain for the forestry was approximated to be 5 - 6 FIM/MWh. The resources of forest processed chips were studied on the basis of stand measurements. According to the study the most remarkable energywood resources were in young thinning stands on Oxalis-Myrtillus and Myrtillus forest site types. On Oxalis-Myrtillus type almost every and on Myrtillus type every second stand included energywood more than 40 m{sup 3}/ha

  10. Wood chips procurement and research project at the Mikkeli region; Puuhakkeen hankinta- ja tutkimusprojekti Mikkelin seudulla

    Energy Technology Data Exchange (ETDEWEB)

    Saksa, T [Finnish Forest Research Inst., Suonenjoki (Finland). Suonenjoki Research Station; Auvinen, P [Mikkeli city (Finland). Dept. of Agriculture and Forestry

    1997-12-31

    In 1993-94, a large-scale energywood production chain started as a co-operation project by the Mikkeli city forest office and local forestry societies. In 1995 over 115 000 m{sup 3} (about 85 000 MWh of energy) of wood chips were delivered to Pursiala heat and power plant in Mikkeli. About 75 % of these chips was forest processed chips. About 70 % of the forest processed chips was whole tree chips from improvement cuttings of young forest stands and the rest was logging waste chips from regeneration cutting areas. The average total delivery costs of forest processed chips after reduction of energywood and other subsidies were approximately 45 FIM/m{sup 3} (60 FIM/MWh) for the whole tree chips and 38 FIM/m{sup 3} (50 FIM/MWh) for logging waste chips. The delivery costs of forest processed chips could meet the target of Bioenergy Research Programme (45 FIM/MWh) only in the most favourable cases. In an average the delivery costs were about 9 FIM/MWh more than the price obtained when sold to the heat and power plant. However the wood chip production created 27 new jobs and the increase of income to the local economy was about 2.2 milj. FIM /year. The local communities got new tax revenue about 3 FIM/MWh. The gain for the forestry was approximated to be 5 - 6 FIM/MWh. The resources of forest processed chips were studied on the basis of stand measurements. According to the study the most remarkable energywood resources were in young thinning stands on Oxalis-Myrtillus and Myrtillus forest site types. On Oxalis-Myrtillus type almost every and on Myrtillus type every second stand included energywood more than 40 m{sup 3}/ha

  11. The research progress of perforating gun inner wall blind hole machining method

    Science.gov (United States)

    Wang, Zhe; Shen, Hongbing

    2018-04-01

    Blind hole processing method has been a concerned technical problem in oil, electronics, aviation and other fields. This paper introduces different methods for blind hole machining, focus on machining method for perforating gun inner wall blind hole processing. Besides, the advantages and disadvantages of different methods are also discussed, and the development trend of blind hole processing were introduced significantly.

  12. 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....

  13. Bridging the gap between research and application -- business plan spreadsheets are helping wood recovery efforts

    Science.gov (United States)

    Philip A. Araman; E. Hager; A.L. Hammett

    1998-01-01

    Wood pallets break or end up in the wrong places where they are no longer useful. They become a waste problem that needs to be dealt with. Many find their way to recovery and repair facilities, but many don’t and most likely end up in landfills. Our charge is to reduce landfilling of unwanted and discarded wood pallets and to push them into highest value uses. To help...

  14. Application of micro-PIXE, MRI and light microscopy for research in wood science and dendroecology

    International Nuclear Information System (INIS)

    Merela, M.; Pelicon, P.; Vavpetic, P.; Regvar, M.; Vogel-Mikus, K.; Sersa, I.; Policnik, H.; Pokorny, B.; Levanic, T.; Oven, P.

    2009-01-01

    Beech (Fagus sylvatica L.) branches were topped and after five months the wound response was analyzed by PIXE, 3D-MRI and light microscopy. From freshly cut and deeply frozen sample 30 μm thick longitudinal-radial tissue sections were prepared for anatomical investigations and micro-PIXE analysis. Light microscopy revealed the structural response to wounding, i.e. occurrence of the reaction zone between the exposed and dehydrated dead tissue and healthy sound wood. The reaction zone was characterized by tylosis in vessels and accumulation of colored deposits in parenchyma cells, fibres and vessels. 3D MRI of a parallel sample showed that the moisture content in the reaction zone was three times higher than in normal healthy wood. Micro-PIXE mapping at margins of compromised wood in beech revealed an increased concentration of potassium in the reaction zone. The increase in the calcium concentration was associated with the dehydrated tissue adjacent to reaction zones. In addition, micro-PIXE was used to determine the elemental distribution in annual tree rings. This may be relevant for retrospective assessment of environmental pollution in wood by measuring yearly increments as a biomonitoring tool. The analysis of European larch (Larix decidua Mill.) wood revealed a high similarity between optical characteristics (i.e. late versus earlywood) and elemental (e.g. Cl, K, Ca, Mn, Zn) distribution.

  15. Wood Products Consumption for Industrial Markets in the United States, Testing a New Research Method

    Science.gov (United States)

    Craig Adair; David B. McKeever

    2013-01-01

    In early 2012, APA-The Engineered Wood Association conducted studies of three industries: institutional furniture, motor homes, and travel trailers and campers. The survey procedure was the same as that used by APA for many years. Lists of individual manufacturers were purchased, a telephone interviewing company was hired to administer a questionnaire, and APA...

  16. Wood burning

    Energy Technology Data Exchange (ETDEWEB)

    Winkelmann, H

    1955-01-01

    Discussed are the use of wood as a fuel, the technique of wood combustion and the operation of wood-burning stoves for cooking and heating. In addition, there is a section which reviews the use of wood stoves in various countries and lists manufacturers of stoves, central heating furnaces and in some cases sawdust burners.

  17. Analysis of experimental researches of wood gasification process in a continuous layer

    OpenAIRE

    Lys, Stepan; Rymar, Tetyana; Yurasova, Oksana; Bura, Mykhaylo

    2017-01-01

    For today are known quite a bit methods redoing of wood and its wastes in energy, but one of the most perspective is gasification. The construction of the gazogene, on which the row of experiments is conducted with the aim of determination of conformity to law of influence of entrance factors which influence on the process of gasification and on quality of synthesis-gas, was worked out for this purpose. The statistical processing of experimental data enables to define ...

  18. Conceptual and empirical themes regarding the design of technology transfer programs : a review of wood utilization research in the United States

    Science.gov (United States)

    Paul V. Ellefson; Michael A. Kilgore; Kenneth E. Skog; Christopher D. Risbrudt

    2011-01-01

    Transfer of technologies produced by research is critical to innovation within all organizations. The intent of this paper is to take stock of the conceptual underpinnings of technology transfer processes as they relate to wood utilization research and to identify conditions that promote the successful transfer of research results. Conceptually, research utilization...

  19. 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...

  20. 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

  1. A technical perspective in modern tree-ring research--how to overcome dendroecological and wood anatomical challenges.

    Science.gov (United States)

    Gärtner, Holger; Cherubini, Paolo; Fonti, Patrick; von Arx, Georg; Schneider, Loïc; Nievergelt, Daniel; Verstege, Anne; Bast, Alexander; Schweingruber, Fritz H; Büntgen, Ulf

    2015-03-05

    Dendroecological research uses information stored in tree rings to understand how single trees and even entire forest ecosystems responded to environmental changes and to finally reconstruct such changes. This is done by analyzing growth variations back in time and correlating various plant-specific parameters to (for example) temperature records. Integrating wood anatomical parameters in these analyses would strengthen reconstructions, even down to intra-annual resolution. We therefore present a protocol on how to sample, prepare, and analyze wooden specimen for common macroscopic analyses, but also for subsequent microscopic analyses. Furthermore we introduce a potential solution for analyzing digital images generated from common small and large specimens to support time-series analyses. The protocol presents the basic steps as they currently can be used. Beyond this, there is an ongoing need for the improvement of existing techniques, and development of new techniques, to record and quantify past and ongoing environmental processes. Traditional wood anatomical research needs to be expanded to include ecological information to this field of research. This would support dendro-scientists who intend to analyze new parameters and develop new methodologies to understand the short and long term effects of specific environmental factors on the anatomy of woody plants.

  2. 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.

  3. Wood Smoke

    Science.gov (United States)

    Smoke is made up of a complex mixture of gases and fine, microscopic particles produced when wood and other organic matter burn. The biggest health threat from wood smoke comes from fine particles (also called particulate matter).

  4. The experimental research on electrodischarge drilling of high aspect ratio holes in Inconel 718

    Science.gov (United States)

    Lipiec, Piotr; Machno, Magdalena; Skoczypiec, Sebastian

    2018-05-01

    In recent years the drilling operations become important area of electrodischarge machining (EDM) application. This especially concerns drilling of, small (D 10) holes in difficult-to-cut materials (i.e. nickel or titanium alloys). Drilling of such a holes is significantly beyond mechanical drilling capabilities. Therefore electrodischarge machining is good and cost efficient alternative for such application. EDM gives possibility to drill accurate, burr free and high aspect ratio holes and is applicable to machine wide range of conductive materials, irrespective of their hardness and toughness. However it is worth to underline its main disadvantages such as: significant tool wear, low material removal rate and poor surface integrity. The last one is especially important in reliable applications in aircraft or medical industry.

  5. 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...

  6. Research of precise pulse plasma arc powder welding technology of thin-walled inner hole parts

    Institute of Scientific and Technical Information of China (English)

    Li Zhanming; Du Xiaokun; Sun Xiaofeng; Song Wei

    2017-01-01

    The inner hole parts played an oriented or supporting role in engineering machinery and equipment,which are prone to appear surface damages such as wear,strain and corrosion.The precise pulse plasma arc powder welding method is used for surface damage repairing of inner hole parts in this paper.The working principle and process of the technology are illustrated,and the microstructure and property of repairing layer by precise pulse plasma powder welding and CO2 gas shielded welding are tested and observed by microscope,micro hardness tester and X-ray residual stress tester etc.Results showed that the substrate deformation of thin-walled inner hole parts samples by precise pulse plasma powder welding is relatively small.The repair layer and substrate is metallurgical bonding,the transition zones (including fusion zone and heat affected zone) are relatively narrow and the welding quality is good.h showed that the thin-walled inner hole parts can be repaired by this technology and equipment.

  7. Research on the EDM Technology for Micro-holes at Complex Spatial Locations

    Science.gov (United States)

    Y Liu, J.; Guo, J. M.; Sun, D. J.; Cai, Y. H.; Ding, L. T.; Jiang, H.

    2017-12-01

    For the demands on machining micro-holes at complex spatial location, several key technical problems are conquered such as micro-Electron Discharge Machining (micro-EDM) power supply system’s development, the host structure’s design and machining process technical. Through developing low-voltage power supply circuit, high-voltage circuit, micro and precision machining circuit and clearance detection system, the narrow pulse and high frequency six-axis EDM machining power supply system is developed to meet the demands on micro-hole discharging machining. With the method of combining the CAD structure design, CAE simulation analysis, modal test, ODS (Operational Deflection Shapes) test and theoretical analysis, the host construction and key axes of the machine tool are optimized to meet the position demands of the micro-holes. Through developing the special deionized water filtration system to make sure that the machining process is stable enough. To verify the machining equipment and processing technical developed in this paper through developing the micro-hole’s processing flow and test on the real machine tool. As shown in the final test results: the efficient micro-EDM machining pulse power supply system, machine tool host system, deionized filtration system and processing method developed in this paper meet the demands on machining micro-holes at complex spatial locations.

  8. 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...

  9. 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 (...

  10. Wood preservation

    Science.gov (United States)

    Rebecca E. Ibach

    1999-01-01

    When left untreated in many outdoor applications, wood becomes subject to degradation by a variety of natural causes. Although some trees possess naturally occurring resistance to decay (Ch. 3, Decay Resistance), many are in short supply or are not grown in ready proximity to markets. Because most commonly used wood species, such as Southern Pine, ponderosa pine, and...

  11. Research of non-uniform multiple hole straighteners for measuring flow rate

    International Nuclear Information System (INIS)

    Wen Duanzhong; Zhong Dezhen; Cai Zhuti

    1989-01-01

    Standard throttling flowmeters are widely used in process flow rate measurement. Enough upstream and downstream straight pipe are necessary for it. If not, the error will be increased. Mounting straightener is an effective way for solving this problem. Advantages of non-uniform multiple hole straighteners studied by authors are good results for straighting, simple in Structure, convenient for mounting and low cost. So it can be popularized in many applications

  12. Black holes

    International Nuclear Information System (INIS)

    Feast, M.W.

    1981-01-01

    This article deals with two questions, namely whether it is possible for black holes to exist, and if the answer is yes, whether we have found any yet. In deciding whether black holes can exist or not the central role in the shaping of our universe played by the forse of gravity is discussed, and in deciding whether we are likely to find black holes in the universe the author looks at the way stars evolve, as well as white dwarfs and neutron stars. He also discusses the problem how to detect a black hole, possible black holes, a southern black hole, massive black holes, as well as why black holes are studied

  13. Report to the Radioactive Waste Management Committee on the first international workshop on seabed disposal of high-level wastes, Woods Hole, Massachusetts, February 16--20, 1976

    International Nuclear Information System (INIS)

    Anderson, D.R.; Hollister, C.D.; Talbert, D.M.

    1976-04-01

    The basic conclusion of the workshop is that, while a very considerable amount of work must be done to assure safety and feasibility, no technical reasons are apparent at this moment that would preclude disposal of radioactive wastes underneath the seafloor. Subsidiary conclusions reached by subgroups dealing with undersea geology, biology, the water column, and disposal canister research are given. General conclusions reached by the workshop are detailed together with proposals for an international program furthering an undersea disposal scheme

  14. Wood Utilization Research Dissemination on the World Wide Web: A Case Study

    Science.gov (United States)

    Daniel L. Schmoldt; Matthew F. Winn; Philip A. Araman

    1997-01-01

    Because many research products are informational rather than tangible, emerging information technologies, such as the multi-media format of the World Wide Web, provide an open and easily accessible mechanism for transferring research to user groups. We have found steady, increasing use of our Web site over the first 6-1/2 months of operation; almost one-third of the...

  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. Fire safety of ETICS with wood fibreboards for multi-storey buildings – first research and development results

    Directory of Open Access Journals (Sweden)

    Küppers Judith

    2016-01-01

    Full Text Available Wood fibreboards can serve as alternative sustainable insulation material for external thermal insulation component systems (ETICS. In Germany, the application of ETICS with wood fibreboards is restricted to low buildings. The restrictions are mainly caused by the smouldering tendency of the wood fibreboards. Thus, the development of an ETICS with wood fibreboards for multi-storey buildings complying with the requirements would provide a new scope of application for this sustainable insulation material. This paper presents first results of standardised and innovative investigation methods as basis for the development. These investigations and analyses concern the fire behaviour, especially smouldering processes, the plaster system, other constructive protection measures as well as risk and safety analyses.

  17. 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.)

  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. 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.

  20. 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....

  1. Acoustic and adsorption properties of submerged wood

    Science.gov (United States)

    Hilde, Calvin Patrick

    Wood is a common material for the manufacture of many products. Submerged wood, in particular, is used in niche markets, such as the creation of musical instruments. An initial study performed on submerged wood from Ootsa Lake, British Columbia, provided results that showed that the wood was not suitable for musical instruments. This thesis re-examined the submerged wood samples. After allowing the wood to age unabated in a laboratory setting, the wood was retested under the hypothesis that the physical acoustic characteristics would improve. It was shown, however, that the acoustic properties became less adequate after being left to sit. The adsorption properties of the submerged wood were examined to show that the submerged wood had a larger accessible area of wood than that of control wood samples. This implied a lower amount of crystalline area within the submerged wood. From the combined adsorption and acoustic data for the submerged wood, relationships between the moisture content and speed of sound were created and combined with previous research to create a proposed model to describe how the speed of sound varies with temperature, moisture content and the moisture content corresponding to complete hydration of sorption sites within the wood.

  2. Black Holes

    OpenAIRE

    Townsend, P. K.

    1997-01-01

    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usu...

  3. Black Holes

    OpenAIRE

    Horowitz, Gary T.; Teukolsky, Saul A.

    1998-01-01

    Black holes are among the most intriguing objects in modern physics. Their influence ranges from powering quasars and other active galactic nuclei, to providing key insights into quantum gravity. We review the observational evidence for black holes, and briefly discuss some of their properties. We also describe some recent developments involving cosmic censorship and the statistical origin of black hole entropy.

  4. Wood for fuel

    Energy Technology Data Exchange (ETDEWEB)

    Beaton, D

    1986-01-01

    Growing wood for energy could contribute three million tonnes of coal equivalent per year by the end of the century. Research programmes in the UK involved with energy forestry are reported. Three systems of wood energy, modified conventional forestry, single stem timber cropping and short rotation coppicing are being investigated. The short rotation coppicing requires inputs similar to those of agricultural crops and the machinery geared towards agricultural operations is compatible with it. Single stem forestry has a medium rotation period of 20 years. The production of coppice wood fuels is discussed in further detail for different parts of the UK with recommendations for species selection and adaption of existing farming practices. A coppice willow harvester has been developed for harvesting during November - February. Weed control and fertilizer application are also briefly mentioned.

  5. Fitting Square Pegs into round Holes: Doing Qualitative Nursing Research in a Quantitative World.

    Science.gov (United States)

    Newton, Lorelei; Kimpson, Sally

    2014-09-01

    The authors, as doctoral candidates and registered nurses, took on a qualitative research project investigating nursing practice in a research-intensive organization. Their aims were to explore and describe how nurses in the ambulatory care setting assist patients and families, including how nursing practice was carried out, constraints to practice, and the influence of the interprofessional milieu. Their first finding, in part because of the qualitative research design used, concerned the potential impact of the organizational ethics review process on the project. The authors discuss how the language, definition of risk, and notion of informed consent articulated in the organizational review process influenced both the research timeline and (potentially) the study itself. While not dismissing the value of ethics review, they explore the tension of overlaying generic criteria for quantitative research, specifically randomized controlled trials, on nursing research from other traditions. Copyright© by Ingram School of Nursing, McGill University.

  6. 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.

  7. 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)

  8. 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.

  9. Characterization of the excavation disturbance caused by boring of the experimental full scale deposition holes in the Research Tunnel of Olkiluoto

    International Nuclear Information System (INIS)

    Autio, J.

    1997-09-01

    Three holes, the size of deposition holes, were bored in the Research Tunnel using a novel full-face boring technique. During the boring test, procedures were carried out in order to determine the effect of changes in operating parameters on the performance of the boring machine and the quality of the hole. Evaluation of the quality of the hole included studies of the geometry of the holes, measurements of surface roughness using a laser profilometer, rock mechanical determinations and study of excavation disturbances in the zone adjacent to the surface of the holes using two novel methods, the He-gas method and the 14 C-polymethylmethacrylate ( 14 C-PMMA) method. It was found that there is a distinct disturbed zone adjacent to the surface of the full scale deposition holes which can be divided into three different zones. The zones are as follows: a crushed zone penetrating to a depth of about 3 mm from the surface, a fractured zone extending to a depth of 6 - 10 mm from the crushed zone and a micro fractured zone extending to a depth of 15 - 31 mm from the fractured zone. The porosity of the rock in the disturbed zone measured using the 14 C-PMMA method was clearly greater than the porosity of undisturbed rock to a depth of about 11 mm. The values of permeability and effective diffusion coefficient in the disturbed zone measured in a direction perpendicular to the disturbed surface were found to be approximately one order of magnitude larger than those of undisturbed rock. The degree of disturbance was found to be greater where higher levels of thrust had been employed during the boring process. The results obtained also suggest that the disturbance caused by using 4- and 5-row cutters in the cutter head is more pronounced than the disturbance caused when using 5- and 6-row cutters

  10. 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.

  11. Quantum aspects of black holes

    CERN Document Server

    2015-01-01

    Beginning with an overview of the theory of black holes by the editor, this book presents a collection of ten chapters by leading physicists dealing with the variety of quantum mechanical and quantum gravitational effects pertinent to black holes. The contributions address topics such as Hawking radiation, the thermodynamics of black holes, the information paradox and firewalls, Monsters, primordial black holes, self-gravitating Bose-Einstein condensates, the formation of small black holes in high energetic collisions of particles, minimal length effects in black holes and small black holes at the Large Hadron Collider. Viewed as a whole the collection provides stimulating reading for researchers and graduate students seeking a summary of the quantum features of black holes.

  12. 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.

  13. RESISTANCE TO THE ATTACK OF DRY-WOOD TERMITES (Cryptotermes brevis) OF SIX WOOD SPECIES

    OpenAIRE

    Fabrício Gomes Gonçalves; José Tarcísio da Silva Oliveira

    2006-01-01

    The dry wood termites are one of the largest causes of damages in wood used in Brazil. This work analyzed the attackof the Cryptotermes brevis in six commercials wood species in the north of the Rio de Janeiro and south of the Espírito Santo. The testobserved the number of holes, the percentage of died individuals and the damage of the pieces. When compared to the Pinus sp(reference), the species with less susceptibility to the attack were Cedrela fissilis, Cariocar brasiliense and Goupia gla...

  14. Holographic research on phase transitions for a five dimensional AdS black hole with conformally coupled scalar hair

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui-Ling, E-mail: LHL51759@126.com [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034 (China); Yang, Shu-Zheng, E-mail: szyangcwnu@126.com [Institute of Theoretical Physics, China West Normal University, Nanchong 637002 (China); Zu, Xiao-Tao, E-mail: xtzu@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

    2017-01-10

    In the framework of holography, we survey the phase structure for a higher dimensional hairy black hole including the effects of the scalar field hair. It is worth emphasizing that, not only black hole entropy, but also entanglement entropy and two point correlation function exhibit the Van der Waals-like phase transition in a fixed scalar charge ensemble. Furthermore, by making use of numerical computation, we show that the Maxwell's equal area law is valid for the first order phase transition. In addition, we also discuss how the hair parameter affects the black hole's phase transition.

  15. 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

  16. 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.

  17. Do Hypervolumes Have Holes?

    Science.gov (United States)

    Blonder, Benjamin

    2016-04-01

    Hypervolumes are used widely to conceptualize niches and trait distributions for both species and communities. Some hypervolumes are expected to be convex, with boundaries defined by only upper and lower limits (e.g., fundamental niches), while others are expected to be maximal, with boundaries defined by the limits of available space (e.g., potential niches). However, observed hypervolumes (e.g., realized niches) could also have holes, defined as unoccupied hyperspace representing deviations from these expectations that may indicate unconsidered ecological or evolutionary processes. Detecting holes in more than two dimensions has to date not been possible. I develop a mathematical approach, implemented in the hypervolume R package, to infer holes in large and high-dimensional data sets. As a demonstration analysis, I assess evidence for vacant niches in a Galapagos finch community on Isabela Island. These mathematical concepts and software tools for detecting holes provide approaches for addressing contemporary research questions across ecology and evolutionary biology.

  18. Conceptual and Empirical Themes regarding the Design of Technology Transfer Programs: A Review of Wood Utilization Research in the United States

    Directory of Open Access Journals (Sweden)

    Paul V. Ellefson

    2011-01-01

    Full Text Available Transfer of technologies produced by research is critical to innovation within all organizations. The intent of this paper is to take stock of the conceptual underpinnings of technology transfer processes as they relate to wood utilization research and to identify conditions that promote the successful transfer of research results. Conceptually, research utilization can be viewed from multiple perspectives, including the haphazard diffusion of knowledge in response to vague and imprecise demands for information, scanning of multiple information sources by individuals and organizations searching for useful scientific knowledge, engagement of third parties to organize research results and communicate them to potential users, and ongoing and active collaboration between researchers and potential users of research. Empirical evidence suggests that various types of programs can promote technology transfer (venture capital, angel investors, business incubators, extension services, tax incentives, and in-house entities, the fundamental effectiveness of which depends on research results that are scientifically valid and consistent with the information needs of potential users. Furthermore, evidence suggests preference toward programs that are appropriately organized and governed, suitably led and creatively administered, and periodically evaluated in accordance with clear standards of success.

  19. Finishing of wood

    Science.gov (United States)

    R. Sam Williams

    1999-01-01

    The primary function of any wood finish (paint, varnish, and stain, for example) is to protect the wood surface, help maintain a certain appearance, and provide a cleanable surface. Although wood can be used both outdoors and indoors without finishing, unfinished wood surfaces exposed to the weather change color, are roughened by photodegradation and surface checking,...

  20. Brane holes

    International Nuclear Information System (INIS)

    Frolov, Valeri P.; Mukohyama, Shinji

    2011-01-01

    The aim of this paper is to demonstrate that in models with large extra dimensions under special conditions one can extract information from the interior of 4D black holes. For this purpose we study an induced geometry on a test brane in the background of a higher-dimensional static black string or a black brane. We show that, at the intersection surface of the test brane and the bulk black string or brane, the induced metric has an event horizon, so that the test brane contains a black hole. We call it a brane hole. When the test brane moves with a constant velocity V with respect to the bulk black object, it also has a brane hole, but its gravitational radius r e is greater than the size of the bulk black string or brane r 0 by the factor (1-V 2 ) -1 . We show that bulk ''photon'' emitted in the region between r 0 and r e can meet the test brane again at a point outside r e . From the point of view of observers on the test brane, the events of emission and capture of the bulk photon are connected by a spacelike curve in the induced geometry. This shows an example in which extra dimensions can be used to extract information from the interior of a lower-dimensional black object. Instead of the bulk black string or brane, one can also consider a bulk geometry without a horizon. We show that nevertheless the induced geometry on the moving test brane can include a brane hole. In such a case the extra dimensions can be used to extract information from the complete region of the brane-hole interior. We discuss thermodynamic properties of brane holes and interesting questions which arise when such an extra-dimensional channel for the information mining exists.

  1. Cement bonded wood wool boards from podocarpus spp. for low ...

    African Journals Online (AJOL)

    ... sound insulation in walls, ceilings and floors, roofs, sound barriers and thermal insulation. Further research is required to investigate the use of different wood species and different mineral binders. Keywords: podocarpus spp, wood-wool, wood-cement composites. Journal of Civil Engineering Research and Practice Vol.

  2. The influence of surface modification on sound absorption coefficient of albizzia wood absorber

    Science.gov (United States)

    Diharjo, Kuncoro; Prabowo, Anditya E.; Jamasri, Suharty, Neng Sri

    2017-01-01

    The purpose of this research is to investigate the influence of surface modification to sound absorption on absorber based albizia wood and kenaf fiber. The absorber was produced using the albizia wood as main materials, and the kenaf fiber was used as acoustic fill. The albizia wood used for producing the absorber was cut in the transverse direction so that its surface had good porosity. The size of specimens had 100 mm in diameter and 40 mm in thickness. The configuration of resonator cavities was 30 mm in diameter and 20 mm in depth, and each resonator was completed with a neck hole of the resonator. The types of surface modification were the addition of screen printing ink, fabric (with and without neck hole), and vinyl-wallpaper (with and without neck hole). According to ISO 10534-2, the absorber specimens were tested using two microphones impedance tube with random noise source to get the curve of noise absorption coefficient (NAC) for each specimen. The result shows that both unmodified absorber and absorber modified with screen printing ink have the similar characteristic of NAC and they are feasible to be used as an absorber in conversation rooms. The addition of fabric and vinyl-wallpaper as cover on the absorber surface give the positive effect of the air gap, and it increases the NAC in low frequency (100-400 Hz). However, the covers decrease the NAC in high frequency (400-1,400 Hz). The holes on the fabric and wallpaper covers give the improvement of NAC.

  3. Who's Counting Dead Wood ?

    OpenAIRE

    Woodall, C. W.; Verkerk, H.; Rondeux, Jacques; Ståhl, G.

    2009-01-01

    Dead wood in forests is a critical component of biodiversity, carbon and nutrient cycles, stand structure, and fuel loadings. Until recently, very few countries have conducted systematic inventories of dead wood resources across their forest lands. This may be changing as an increasing number of countries implement dead wood inventories. A recent survey looks at the status and attributes of forest dead wood inventories in over 60 countries. About 13 percent of countries inventory dead wood gl...

  4. Wood Composite Adhesives

    Science.gov (United States)

    Gomez-Bueso, Jose; Haupt, Robert

    The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

  5. 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.

  6. White holes and eternal black holes

    International Nuclear Information System (INIS)

    Hsu, Stephen D H

    2012-01-01

    We investigate isolated white holes surrounded by vacuum, which correspond to the time reversal of eternal black holes that do not evaporate. We show that isolated white holes produce quasi-thermal Hawking radiation. The time reversal of this radiation, incident on a black hole precursor, constitutes a special preparation that will cause the black hole to become eternal. (paper)

  7. 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...

  8. Peter Koch: wizard of wood use

    Science.gov (United States)

    M.E. Lora

    1978-01-01

    Like his pioneer forefathers, Peter Koch sees opportunity where others see obstacles. And his vision is helping to reshape the wood industry. Since 1963 Koch has directed research on processing southern woods for the U.S. Forest Service's Southern Forest Experiment Station in Pineville, Louisiana. In that time, he has invented six revolutionary machines, developed...

  9. 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...

  10. Using open hole and cased-hole resistivity logs to monitor gas hydrate dissociation during a thermal test in the mallik 5L-38 research well, Mackenzie Delta, Canada

    Science.gov (United States)

    Anderson, B.I.; Collett, T.S.; Lewis, R.E.; Dubourg, I.

    2008-01-01

    Gas hydrates, which are naturally occurring ice-like combinations of gas and water, have the potential to provide vast amounts of natural gas from the world's oceans and polar regions. However, producing gas economically from hydrates entails major technical challenges. Proposed recovery methods such as dissociating or melting gas hydrates by heating or depressurization are currently being tested. One such test was conducted in northern Canada by the partners in the Mallik 2002 Gas Hydrate Production Research Well Program. This paper describes how resistivity logs were used to determine the size of the annular region of gas hydrate dissociation that occurred around the wellbore during the thermal test in the Mallik 5L-38 well. An open-hole logging suite, run prior to the thermal test, included array induction, array laterolog, nuclear magnetic resonance and 1.1-GHz electromagnetic propagation logs. The reservoir saturation tool was run both before and after the thermal test to monitor formation changes. A cased-hole formation resistivity log was run after the test.Baseline resistivity values in each formation layer (Rt) were established from the deep laterolog data. The resistivity in the region of gas hydrate dissociation near the wellbore (Rxo) was determined from electromagnetic propagation and reservoir saturation tool measurements. The radius of hydrate dissociation as a function of depth was then determined by means of iterative forward modeling of cased-hole formation resistivity tool response. The solution was obtained by varying the modeled dissociation radius until the modeled log overlaid the field log. Pretest gas hydrate production computer simulations had predicted that dissociation would take place at a uniform radius over the 13-ft test interval. However, the post-test resistivity modeling showed that this was not the case. The resistivity-derived dissociation radius was greatest near the outlet of the pipe that circulated hot water in the wellbore

  11. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for

  12. Understanding key issues of sustainable wood production in the Pacific Northwest.

    Science.gov (United States)

    Robert L. Deal; Seth M. White

    2005-01-01

    Researchers involved with the Pacific Northwest (PNW) Research Station Sustainable Wood Production Initiative have outlined some of the barriers and opportunities for sustainable wood production in the region. Sustainable wood production is defined as the capacity of forests to produce wood, products, and services on a long-term basis and in the context of human...

  13. Black hole gravitohydromagnetics

    CERN Document Server

    Punsly, Brian

    2008-01-01

    Black hole gravitohydromagnetics (GHM) is developed from the rudiments to the frontiers of research in this book. GHM describes plasma interactions that combine the effects of gravity and a strong magnetic field, in the vicinity (ergosphere) of a rapidly rotating black hole. This topic was created in response to the astrophysical quest to understand the central engines of radio loud extragalactic radio sources. The theory describes a "torsional tug of war" between rotating ergospheric plasma and the distant asymptotic plasma that extracts the rotational inertia of the black hole. The recoil from the struggle between electromagnetic and gravitational forces near the event horizon is manifested as a powerful pair of magnetized particle beams (jets) that are ejected at nearly the speed of light. These bipolar jets feed large-scale magnetized plasmoids on scales as large as millions of light years (the radio lobes of extragalactic radio sources). This interaction can initiate jets that transport energy fluxes exc...

  14. 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)

  15. 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 ...

  16. 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 ( ...

  17. 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 ...

  18. Robert Wood Johnson Foundation

    Science.gov (United States)

    Robert Wood Johnson Foundation Search How We Work Our Focus Areas About RWJF Search Menu How We Work Grants ... Learn more For Grantees and Grantseekers The Robert Wood Johnson Foundation funds a wide array of programs ...

  19. 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...

  20. Hole superconductivity

    International Nuclear Information System (INIS)

    Hirsch, J.E.; Marsiglio, F.

    1989-01-01

    The authors review recent work on a mechanism proposed to explain high T c superconductivity in oxides as well as superconductivity of conventional materials. It is based on pairing of hole carriers through their direct Coulomb interaction, and gives rise to superconductivity because of the momentum dependence of the repulsive interaction in the solid state environment. In the regime of parameters appropriate for high T c oxides this mechanism leads to characteristic signatures that should be experimentally verifiable. In the regime of conventional superconductors most of these signatures become unobservable, but the characteristic dependence of T c on band filling survives. New features discussed her include the demonstration that superconductivity can result from repulsive interactions even if the gap function does not change sign and the inclusion of a self-energy correction to the hole propagator that reduces the range of band filling where T c is not zero

  1. Adhesive interactions with wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    While the chemistry for the polymerization of wood adhesives has been studied systematically and extensively, the critical aspects of the interaction of adhesives with wood are less clearly understood. General theories of bond formation need to be modified to take into account the porosity of wood and the ability of chemicals to be absorbed into the cell wall....

  2. Soil-wood interactions

    NARCIS (Netherlands)

    Wal, van der Annemieke; klein Gunnewiek, Paulien; Boer, de Wietse

    2017-01-01

    Wood-inhabiting fungi may affect soil fungal communities directly underneath decaying wood via their exploratory hyphae. In addition, differences in wood leachates between decaying tree species may influence soil fungal communities. We determined the composition of fungi in 4-yr old decaying logs

  3. 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...

  4. 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...

  5. 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....

  6. 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

  7. Permian Silicified Wood in Oman

    Czech Academy of Sciences Publication Activity Database

    Matysová, Petra; Grygar, Tomáš

    -, č. 15 (2009), s. 14-18 ISSN N Institutional research plan: CEZ:AV0Z30460519; CEZ:AV0Z40320502 Keywords : silicified wood * Oman * geology Subject RIV: DD - Geochemistry www.geologyoman.com/gso/Haj(Nov09).pdf

  8. 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.

  9. 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.

  10. 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.

  11. Research on Impact Stress and Fatigue Simulation of a New Down-to-the-Hole Impactor Based on ANSYS

    Science.gov (United States)

    Wu, Tao; Wang, Wei; Yao, Aiguo; Li, Yongbo; He, Wangyong; Fei, Dongdong

    2018-06-01

    In the present work, a down-to-the-hole electric hammer driven by linear motor is reported for drilling engineering. It differs from the common hydraulic or pneumatic hammers in that it can be applied to some special occasions without circulating medium due to its independence of the drilling fluid. The impact stress caused by the reciprocating motion between stator and rotor and the fatigue damage in key components of linear motor are analyzed by the ANSYS Workbench software and 3D model. Based on simulation results, the hammer's structure is optimized by using special sliding bearing, increasing the wall thickness of key and multilayer buffer gasket. Fatigue life and coefficient issues of the new structure are dramatically improved. However buffer gasket reduces the impactor's energy, different bumper structure effect on life improving and energy loss have also been elaborated.

  12. Wood evidence : proper collection, documentation, and storage of wood evidence from a crime scene

    Science.gov (United States)

    Alex Wiedenhoeft

    2006-01-01

    Wood can be found at crime scenes in many forms: as a murder weapon, as material used to hide a body, or as trace evidence from forced entry or vandalism. In the course of my work at the Forest Products Laboratory, Center for Wood Anatomy Research, I have been part of several forensic investigations that were adversely affected by inappropriate procedures used to...

  13. RESISTANCE TO THE ATTACK OF DRY-WOOD TERMITES (Cryptotermes brevis OF SIX WOOD SPECIES

    Directory of Open Access Journals (Sweden)

    Fabrício Gomes Gonçalves

    2006-03-01

    Full Text Available The dry wood termites are one of the largest causes of damages in wood used in Brazil. This work analyzed the attackof the Cryptotermes brevis in six commercials wood species in the north of the Rio de Janeiro and south of the Espírito Santo. The testobserved the number of holes, the percentage of died individuals and the damage of the pieces. When compared to the Pinus sp(reference, the species with less susceptibility to the attack were Cedrela fissilis, Cariocar brasiliense and Goupia glabra, that alsopresented the largest percentages of mortality of termites. The Schizolobium parahyba, Toona ciliata and the Tachigalia myrmecophyllawere the species with the highest level of damage.

  14. Energy use of decayed wood; Lahopuun maeaerae, sisaeltoe ja hankintakustannukset

    Energy Technology Data Exchange (ETDEWEB)

    Maekelae, M; Lipponen, K [Metsaeteho Oy, Helsinki (Finland)

    1997-12-01

    A study of the quality, amounts and delivery costs of decayed wood available for possible energy use will be carried out in co-operation by Metsaeteho and Forest Research Institute. The work will consist of the following sub-studies: Quality of decayed wood available for possible energy use, quantities of decayed wood available for possible energy use by municipalities in Western and Southern Finland, harvesting, transport and chipping costs of decayed wood in different delivery alternatives and as a practical example, quantities of decayed wood available for possible energy use in two potential consumption municipalities. (orig.)

  15. Many Roles of Wood Adhesives

    Science.gov (United States)

    Charles R. Frihart

    2014-01-01

    Although wood bonding is one of the oldest applications of adhesives, going back to early recorded history (1), some aspects of wood bonds are still not fully understood. Most books in the general area of adhesives and adhesion do not cover wood bonding. However, a clearer understanding of wood bonding and wood adhesives can lead to improved products. This is important...

  16. 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.

  17. Controversy. The wood war

    International Nuclear Information System (INIS)

    James, O.

    2010-01-01

    The author comments the conflict emerging in France between industries exploiting wood for construction and those exploiting it as a heating material for power generation. The first ones accuse the others to steal their raw material, to pull the prices up, and to destabilize the sector. This conflict takes place notably around sawmill wastes which are used either by wood panel fabricators or by wood pellets producers. Both sectors are claiming they are creating more jobs than the other. The French forest indeed offers good opportunities for both sectors, but other countries which are lacking forest surfaces, are buying wood in France. Several issues are matter of discussion: burning wood seems to go against the reduction of greenhouse gas emissions, subsidies awarded to big heater projects. The situation of the wood sector in Austria, Finland and Poland is briefly presented

  18. 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.

  19. Emissions from wood domestic heating appliances

    International Nuclear Information System (INIS)

    Collet, S.

    2009-01-01

    Much research has been carried out to study emissions from wood domestic heating appliances. This work reviews the available emission factors about pollutants produced in different types of wood domestic heating appliances. The main sources of pollutants are older stoves that in most cases are used as an additional heating appliance. These stoves causes higher emissions than modern appliances. Then, substitution of an old type wood appliance with a modern appliance or boiler or a pellet boilers, would reduce considerably emissions in this sector. The efficiency of this measure is estimated for each pollutant. (author)

  20. 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...

  1. Life-cycle environmental performance of renewable building materials in the context of residential construction : phase II research report : an extension to the 2005 phase I research report. Module N, Life-cycle inventory of manufacturing prefinished engineered wood flooring in the eastern United States

    Science.gov (United States)

    Richard D. Bergman; Scott A. Bowe

    2011-01-01

    This study summarizes the environmental performance of prefinished engineered wood flooring using life-cycle inventory (LCI) analysis. Using primary mill data gathered from manufacturers in the eastern United States and applying the methods found in Consortium for Research on Renewable Industrial Materials (CORRIM) Research Guidelines and International Organization of...

  2. 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....

  3. 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

  4. Langley Research Highlights 1999: Advanced Aerospace Technology Clouds That Help Create the Ozone Hole Capturing Comet Dust

    Science.gov (United States)

    2000-01-01

    This report contains highlights of some of the major accomplishments and applications made by NASA Langley Research Center and its university partners and industry colleagues during 1999. The highlights illustrate the broad range of research and technology activities carried out by NASA Langley and the contributions of this work toward maintaining United States' leadership in aeronautics and space research. The Center's historic national role since 1917 continues in Aerospace Technology research with an additional major role in Earth Science research. Langley also partners closely with other NASA Centers and the Jet Propulsion Laboratory in Space Science and the Human Exploration and Development of Space. A color version is available at http://larcpubs.larc.nasa.gov/randt/1999/. For further information, contact Dennis Bushnell, Senior Scientist, Mail Stop 110, NASA Langley Research Center, Hampton, Virginia 23681-2199, (757)-864-8987, e-mail address: d.m.bushnell@larc.nasa.gov.

  5. Wood pellets : is it a reliable, sustainable, green energy option?

    International Nuclear Information System (INIS)

    Swaan, J.

    2006-01-01

    The Wood Pellet Association of Canada was formerly called the BC Pellet Fuel Manufacturers Association, and was renamed and re-organized in January 2006. The association serves as an advocate for the wood pellet industry in addition to conducting research projects. This power point presentation presented an overview of the wood pellet industry in North America and Europe. Canada's 23 pellet plants currently produce just over 1,000,000 tons of wood pellets annually. Pellet producers in the United States produce approximately 800,000 tons annually for the residential bagged market. There are currently 240 pellet plants in Europe, and district heating is the largest growth market for wood pellets in Europe. British Columbia (BC) pellet producers will ship 450,000 tons to European power plants in 2005. Wood pellet specifications were presented, with details of calorific values, moisture and ash contents. An outline of wood pellet production processes was provided. New pellet plants currently under construction were reviewed. Domestic, North American and overseas exports were discussed, along with production estimates for BC for the next 5 years. A chart of world production and consumption of wood pellets between 2000 to 2010 was presented. North American wood pellet technologies were described. The impact of the pine beetle infestation in BC on the wood pellet industry was evaluated, and a worldwide wood pellet production growth forecast was presented. Issues concerning off-gassing, emissions, and torrifracation were also discussed. tabs., figs

  6. 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.)

  7. 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 (...

  8. 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...

  9. How James Wood Works

    Science.gov (United States)

    Goldstein, Evan R., Comp.

    2008-01-01

    Reading through news-media clippings about James Wood, one might reasonably conclude that "pre-eminent critic" is his official job title. In fact, Wood is a staff writer for "The New Yorker" and a professor of the practice of literary criticism at Harvard University. But at a time when there is much hand-wringing about the death of the…

  10. Method of stabilizing wood

    International Nuclear Information System (INIS)

    Pesek, M.; Jarkovsky, J.

    1973-01-01

    Wood is impregnated with a mixture of a vinyl or an allyl monomer (20 - 90 wt. %) and unsaturated polyester resins. The impregnated wood is then exposed to ionizing radiation at doses of 0.1 to 20 Mrad at a temperature of 60 to 180 degC. (B.S.)

  11. Chemical modification of wood

    Science.gov (United States)

    Roger M. Rowell

    2007-01-01

    After millions of years of evolution, wood was designed to perform in a wet environment, and nature is programmed to recycle it, in a timely way, back to the basic building blocks of carbon dioxide and water through biological, thermal, aqueous, photochemical, chemical, and mechanical degradation. The properties of wood are, for the most part, a result of the chemistry...

  12. ASW Research at WHOI and SIO

    Science.gov (United States)

    2016-06-07

    Science Category 3: Deep Water Acoustic Propagation- Jim Lynch -1 3098705, Part C- Deep Water Acoustic Propagation- $102,149 Science Category 4...Technical Report 2011-04, (Woods Hole Oceanographic Institution, Woods Hole , MA). Stephen , R. A., Spiess, F. N., Collins , J. A. , Hildebrand, J . A

  13. Methods for size classification of wood chips

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Hans; Boehm, Thorsten [Technologie- und Foerderzentrum im Kompetenzzentrum fuer Nachwachsende Rohstoffe (TFZ), Schulgasse 18, D-94315 Straubing (Germany); Daugbjerg Jensen, Peter [Forest and Landscape FLD, The Royal Veterinary and Agricultural University, Rolighedsvej 23, DK-1958 Frederiksberg C (Denmark); Temmerman, Michaeel; Rabier, Fabienne [Centre wallon de Recherches agronomiques CRA-W Departement Genie rural, 146, Chaussee de Namur, B-5030 Gembloux (Belgium); Golser, Michael [Holzforschung Austria HFA Franz Grill-Stra beta e 7, A-1031 Wien (Austria)

    2006-11-15

    Methods for size classification of wood chips were analysed in an international round robin using 13 conventional wood chip samples and two specially prepared standard samples, one from wood chips and one from hog fuel. The true size distribution of these two samples (according to length, width and height) had been determined stereometrically (reference method) using a digital calliper gauge and by weighing each of the about 7000 wood particles per sample. Five different horizontal and three rotary screening devices were tested using five different screen hole diameters (3.15, 8, 16, 45, 63mm, round holes). These systems are compared to a commercially available continuously measuring image analysis equipment. The results show that among the devices of a measuring principle-horizontal and rotary screening-the results are quite comparable, while there is a severe incompatibility when distributions are determined by different measuring principles. Highest conformity with the reference values is given for measurements with an image analysis system, whereas for all machines with horizontal screens the median value of the size distribution only reached between one-third to half of the reference median value for the particle length distribution. These deviations can be attributed to a higher particle misplacement, which is particularly found in the larger fractions. Such differences decrease when the particle's shape is more roundish (i.e. sphericity closer to one). The median values of length distributions from screenings with a rotary classifier are between the measurements from an image analysis and horizontal screening devices. (author)

  14. 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.

  15. PHYSICAL ANALYSIS OF QUALITY WOOD Melia azedarach

    Directory of Open Access Journals (Sweden)

    T. J. da Silva

    2016-07-01

    Full Text Available Forest species, in general, present a slow growth, which results and profits can manifest themselves in the long run, it becomes necessary the study and discovery of new species that may provide raw materials and return on invested capital more immediate, being that the Melia azedarach wood is a potential option. In the absence of information about, the objective of this paper is to determine its physical properties: basic density and shrinkage of the Melia azedarach species in the Itapeva-SP region. The data obtained in this study allow to classify wood Melia azedarach as wood of average density and good dimensional stability. Feature that makes it ideal for its use in furniture industry. The low amount of research related to quality of this wood prevents the commercial use of it to achieve its full potential harnessing its effectively, and essential investments in this field.

  16. Wood ethanol and synthetic natural gas pathways

    International Nuclear Information System (INIS)

    2006-01-01

    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

  17. Black holes. Chapter 6

    International Nuclear Information System (INIS)

    Penrose, R.

    1980-01-01

    Conditions for the formation of a black hole are considered, and the properties of black holes. The possibility of Cygnus X-1 as a black hole is discussed. Einstein's theory of general relativity in relation to the formation of black holes is discussed. (U.K.)

  18. Search for black holes

    International Nuclear Information System (INIS)

    Cherepashchuk, Anatolii M

    2003-01-01

    Methods and results of searching for stellar mass black holes in binary systems and for supermassive black holes in galactic nuclei of different types are described. As of now (June 2002), a total of 100 black hole candidates are known. All the necessary conditions Einstein's General Relativity imposes on the observational properties of black holes are satisfied for candidate objects available, thus further assuring the existence of black holes in the Universe. Prospects for obtaining sufficient criteria for reliably distinguishing candidate black holes from real black holes are discussed. (reviews of topical problems)

  19. 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...

  20. 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

  1. 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.

  2. 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...

  3. 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)

  4. Synchrotron based x-ray fluorescence microscopy confirms copper in the corrosion products of metals in contact with treated wood

    Science.gov (United States)

    Samuel L. Zelinka; Joseph E. Jakes; Grant T. Kirker; David Vine; Stefan Vogt

    2017-01-01

    Copper based waterborne wood preservatives are frequently used to extend the service life of wood products when subjected to frequent moisture exposure. While these copper based treatments protect the wood from fungal decay and insect attack, they increase the corrosion of metals embedded or in contact with the treated wood. Previous research has shown the most...

  5. A Review of Relationships Between Wood Quality and Silvicultural Practices

    Directory of Open Access Journals (Sweden)

    Tomy Listyanto

    2009-07-01

    Full Text Available The effect of silviculture on wood quality has been approached from different perspectives. This relationship is being a critical concern of forest managers, landowners, and also researchers. Reliable information is needed to support forest managers in predicting the consequences of various silvicultural practices in terms of quantity and wood quality. Wood has beed used for a variety of products. Each product has particular requirements regarding quality. The variation of wood quality requirement allows industries to decide to use timber resource appropriate for their products. Silvicultural practives cover all treatments applied in forest stand management especially to improve the quality of stand, including manipulation of the availability of sunlight, nutrient and water by using several treatments such as thinning, control of spacing, fertilizing, and pruning. The quality of stand is aimed to achieve particular forest management objectives including higher wood quality. There is no broad generalization regarding the relation between silvicultural practice and wood quality. Many investigators showed positive results in relation to producing high quality of wood products, while other researchers revealed negative effects. Reliable information is needed to support forest managers in predicting the consequences of various silvicultural practices in relation to the wood quantity and quality. Continuous research is needed to find methods of producing wood of high quality based on silvicultural practices and genetic improvement which can be used in wider area by considering limitation including environment and geographic variation.

  6. Preliminary studies of Brazilian wood using different radioisotopic sources

    International Nuclear Information System (INIS)

    Carvalho, Gilberto; Silva, Leonardo Gondim de Andrade e

    2013-01-01

    Due to availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instrument; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere with the growth of trees. This behavior explains why average physical-chemical properties are important when wood is studied. The majority of researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties of wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: 'freijo', 'jequetiba', 'muiracatiara' and 'ipe'. For wood density determination by non-conventional method, Am-241, Ba-133 and Cs-137 radioisotopic sources; a NaI scintillation detector and a counter were used. The results demonstrated this technique to be quick and accurate. By considering the nuclear parameters obtained as half value layers and linear absorption coefficients, Cs-137 radioisotopic source demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. (author)

  7. A Dancing Black Hole

    Science.gov (United States)

    Shoemaker, Deirdre; Smith, Kenneth; Schnetter, Erik; Fiske, David; Laguna, Pablo; Pullin, Jorge

    2002-04-01

    Recently, stationary black holes have been successfully simulated for up to times of approximately 600-1000M, where M is the mass of the black hole. Considering that the expected burst of gravitational radiation from a binary black hole merger would last approximately 200-500M, black hole codes are approaching the point where simulations of mergers may be feasible. We will present two types of simulations of single black holes obtained with a code based on the Baumgarte-Shapiro-Shibata-Nakamura formulation of the Einstein evolution equations. One type of simulations addresses the stability properties of stationary black hole evolutions. The second type of simulations demonstrates the ability of our code to move a black hole through the computational domain. This is accomplished by shifting the stationary black hole solution to a coordinate system in which the location of the black hole is time dependent.

  8. Implementation of κ0-NAA at the NAA No.1 irradiation hole in the HANARO research reactor

    International Nuclear Information System (INIS)

    Moon, Jong Hwa; Kim, Sun Ha; Chung, Yong Sam; Kim, Young Jin

    2005-01-01

    κ 0 -NAA is known as one of the most remarkable progresses of the NAA with it's many advantages. Efforts have been made to implement of κ 0 -NAA method at the NAA No.1 irradiation position where the neutrons are well thermalized in the HANARO research reactor, KAERI, Korea. For this objective, the α and f values were measured and the values were 0.127 and 1014, respectively. To evaluate the applicability of κ 0 -NAA in our analytical system, the analysis of three kinds of SRMs was executed. The analytical results showed that the relative error of most of the elements was less than 10 % and the U-scores were within 2. In addition, for a routine analysis by κ 0 -NAA, an attempt was made to apply a program called 'ADVNAA' developed by the China Institute of Atomic Energy, China. Consequently, the ADVNAA program which was modified for our measurement system turned out to be available for a practical application of air particulates

  9. Acidity of selected industrial wood species in Serbia

    Directory of Open Access Journals (Sweden)

    Popović Mlađan

    2016-01-01

    Full Text Available The acidity of wood has an important role in many areas of wood applications. Hence, this paper presents a study on the acidity of beech, fir and poplar, as the representatives of the most industrially utilized wood species in Serbia. The contents of both the soluble and insoluble acids were determined through the extraction methods with cold distilled water and sodium acetate solution, respectively, followed by the titration with sodium hydroxide solution. The acidity strongly differs among the three wood species used in this research. The amount of insoluble acids was the highest in fir, almost twice as much than in poplar, and about 68 % higher than in fir wood species. Such differences also showed a strong correlation with the gel times of UF adhesive mixes with hot water extracts. [Projekat Ministarstva nauke Republike Srbije, br. TP 31041: Establishment of Wood Plantations Intended for Afforestation of Serbia

  10. Fiscal 1982 Sunshine Project research report. Development of bore hole measurement technology; 1982 nendo koseinai sokutei gijutsu no kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1983-03-01

    This report summarizes the fiscal 1982 research result on development of measuring instruments for information collection in geothermal bore holes under high-temperature high-pressure conditions. In development of high-temperature well logging cable, the new TFE Teflon insulated well logging cable (3,300m) applicable up to 320 degreesC was prepared. In development of digital well logging system, the data analyzer for edition and analysis of recorded digital logging data, the depth panel with an automatic depth correction mechanism, and the fiber optics controller were prepared. Preparation of the whole digital well logging system was thus completed. Field test was made at 3 wells in 2 geothermal areas. At the test well in Nigori-Gawa area, Hokkaido, performance test was made on the digital well logging system, TFE Teflon well logging cable, and improved winch completed in this fiscal year. At the same time, the radioactive well logging test using radioactive isotope showed the satisfactory result except neutron well logging. (NEDO)

  11. Wood supply at the edge of the world

    DEFF Research Database (Denmark)

    Pinta, Elie; Baittinger, Claudia

    Wood used in construction and boat building, in domestic productions or as a fuel resource was a key material for medieval North European societies. For people living in Medieval Scandinavia, trees and timber were common in both landscapes and mythology and therefore essential cultural items...... is to present the current research on the identification of wood species (both local and imported) used by European settlers in Greenland. An analysis of wood will help us to understand and retrace the origin and circulation of wood resources in the Norse settlements. What was the nature of woodworking...

  12. Air quality and composite wood products

    Science.gov (United States)

    Melissa G. D. Baumann

    1999-01-01

    Research at the USDA Forest Service, Forest Products Laboratory (FPL) is being conducted to identify the compounds emitted from wood products during their manufacture and subsequent use. The FPL researchers are measuring the types and quantities of VOCs that are emitted from particleboard and MDF products to provide quantitative emissions information. This information...

  13. 2005 NCALM Plum Island-Woods Hole Marine Biological Laboratory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The survey area is an irregular polygon (148 square kilometers) at the Plum Island River in northeast Massachusetts. The eastern third of the polygon was flown on...

  14. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    large values of Ф, black holes do form and for small values the scalar field ... on the near side of the ridge ultimately evolve to form black holes while those configu- ... The inset shows a bird's eye view looking down on the saddle point.

  15. Black hole hair removal

    International Nuclear Information System (INIS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-01-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair - degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  16. Sustainable production of wood and non-wood forest products: Proceedings of IUFRO Division 5 Research Groups 5.11 and 5.12, Rotorua, New Zealand, March 11–15, 2003.

    Science.gov (United States)

    E.M. Donoghue; G.L. Benson; J.L. Chamberlain

    2004-01-01

    This proceedings is a collection of 18 papers and extended abstracts based on talks presented at the International Union of Forest Research Organizations (IUFRO) All Division 5 Conference, held in Rotorua, New Zealand, March 11–15, 2003. This conference emphasized the many ways that forest products research can contribute to sustainable choices in forest management....

  17. 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.

  18. The influence of irradiated wood filler on some properties of polypropylene - wood composites

    Directory of Open Access Journals (Sweden)

    Điporović-Momčilović Milanka

    2007-01-01

    Full Text Available The problem of compatibility between the wood filler and thermoplastic matrix is of essential importance in composite production. Numerous methods have been developed for increasing this compatibility, which is still representing a challenging objective of composite research throughout the world. The research into these methods is primarily directed towards their efficiency from the viewpoint of the composite performance and their economical acceptability. The latter is of particular importance for the composite production in the developing countries with respect to the shortage of the corresponding funds. With this respect, the utilization of ionizing radiation might have considerable advantages. In this research, the beech wood flour was irradiated by a dose of 10 kGy of 60Co gamma rays for purpose of provoking the changes by the ionizing effect. The effects of ionizing radiation upon the properties of wood particles have been examined by IR spectroscopy and by determination of contents of hydroxyl groups in wood by acetylating as an indirect method. All these methods have been expected to reveal the chemical effects of the applied radiation treatment. The irradiated and the control wood flour were used in order to produce the samples of composite with polypropylene. The polypropylene-wood flour (PP-WF composites were produced with 40% of wood particles having fraction size 0.3 mm. The melt-blended composites were modified with amido-acrylic acid (AMACA as a new coupling agent synthesized for this propose in amount of 6 wt.% (based on wood filler and successively with 0.05 wt.% (based on PP of organic peroxide during mixing step. The composites containing coupling agents showed superior mechanical properties, compared to the untreated one. The highest extent of improvement of tensile was achieved in PP-WFl composites modified with AMACA coupling agent.

  19. Installation, care, and maintenance of wood shake and shingle roofs

    Science.gov (United States)

    Tony Bonura; Jack Dwyer; Arnie Nebelsick; Brent Stuart; R. Sam Williams; Christopher Hunt

    2011-01-01

    This article gives general guidelines for selection, installation, finishing, and maintenance of wood shake and shingle roofs. The authors have gathered information from a variety of sources: research publications on wood finishing, technical data sheets from paint manufacturers, installation instructions for shake and shingle roofs, and interviews with experts having...

  20. Installation, care, and maintenance of wood shake and shingle siding

    Science.gov (United States)

    Jack Dwyer; Tony Bonura; Arnie Nebelsick; Sam Williams; Christopher G. Hunt

    2011-01-01

    This article gives general guidelines for selection, installation, finishing, and maintenance of wood shakes and shingles. The authors gathered information from a variety of sources: research publications on wood finishing, technical data sheets from paint manufacturers, installation instructions for shake and shingle siding, and interviews with experts having...

  1. Development and application of wood adhesives in China

    Science.gov (United States)

    Jiyou Gu; Zhiyong Cai

    2010-01-01

    Rapid economic development and growth in China has resulted in a substantial increase in the demand for utilization of bio-based composites. This provides a unique opportunity for developing wood adhesives. This study reviews research development and major accomplishments in wood adhesives and technology in China over the last 50 years. It also discusses the...

  2. Applications of infrared photo-acoustic spectroscopy for wood samples

    Science.gov (United States)

    Mon-Lin Kuo; John F. McClelland; Siquan Luo; Po-Liang Chien; R.D. Walker; Chung-Yun Hse

    1988-01-01

    Various infrared (IR) spectroscopic techniques for the analysis of wood samples are briefly discussed. Theories and instrumentation of the newly developed photoacoustic spectroscopic (PAS) technique for measuring absorbance spectra of solids are presented. Some important applications of the PAS technique in wood science research are discussed. The application of the...

  3. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  4. Black holes without firewalls

    Science.gov (United States)

    Larjo, Klaus; Lowe, David A.; Thorlacius, Larus

    2013-05-01

    The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and reemits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of the order of the black hole scrambling time.

  5. Black holes are hot

    International Nuclear Information System (INIS)

    Gibbons, G.

    1976-01-01

    Recent work, which has been investigating the use of the concept of entropy with respect to gravitating systems, black holes and the universe as a whole, is discussed. The resulting theory of black holes assigns a finite temperature to them -about 10 -7 K for ordinary black holes of stellar mass -which is in complete agreement with thermodynamical concepts. It is also shown that black holes must continuously emit particles just like ordinary bodies which have a certain temperature. (U.K.)

  6. EVOLUTION OF LIGHTWEIGHT WOOD COMPOSITES

    Directory of Open Access Journals (Sweden)

    Marius C. BARBU

    2016-01-01

    Full Text Available Lightweight boards and beams in the wood-based construction and furniture industry are not a new topic. The density reduction of panels using sandwich structure with light cores was confirmed by users like doors or mobile homes more than three decades ago. Today many ways to attain a lighter wooden structure are on offer, partially in industrial application. The first one is the use of light-weight wood species like balsa, lime, pine from southern hemisphere plantations etc. limited by the availability, strength properties, gluability and so on. A second one is the sandwich structure made from hard faces like thick veneer, thin plywood, particleboard or high density thin fiberboard and cores made from honeycomb paper, very light wood species or foams like the polystyrene one. A third way to produce a light structure is to reduce the core drastically, using predesigned skeletons with special shapes and connections to the faces. The engines for these developments are on the one hand the fast growing market of knockdown furniture and on the other hand the increasing costs for energy and raw materials. Additional factors that make weight saving a primary economical objective for most producers are transportation costs, easier handling and higher acceptance among the end users. Moreover, customers demand more for ergonomical solutions regarding packaging. Many patents were generated by researchers and developers for new one-stage production processes for sandwich panels with wood- and impregnated paper-based facings made from veneers, particles or fibres and a core consisting of expandable foams, particles or embedded hard skeletons. These ideas or prototypes could be integrated in existing continuous pressing lines for wood based panels keeping some of the advantages of the continuous production technique in matters of efficiency. Some of the challenges of the light weight wooden structure are the connection in half or final parts, resistance to

  7. Monopole Black Hole Skyrmions

    OpenAIRE

    Moss, Ian G; Shiiki, N; Winstanley, E

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  8. Ballistic hole magnetic microscopy

    NARCIS (Netherlands)

    Haq, E.; Banerjee, T.; Siekman, M.H.; Lodder, J.C.; Jansen, R.

    2005-01-01

    A technique to study nanoscale spin transport of holes is presented: ballistic hole magnetic microscopy. The tip of a scanning tunneling microscope is used to inject hot electrons into a ferromagnetic heterostructure, where inelastic decay creates a distribution of electron-hole pairs.

  9. What is black hole?

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. What is black hole? Possible end phase of a star: A star is a massive, luminous ball of plasma having continuous nuclear burning. Star exhausts nuclear fuel →. White Dwarf, Neutron Star, Black Hole. Black hole's gravitational field is so powerful that even ...

  10. 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)

  11. 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.

  12. Wood plastic combination

    International Nuclear Information System (INIS)

    Cunanan, S.A.; Bonoan, L.S.; Verceluz, F.P.; Azucena, E.A.

    1976-03-01

    The purpose of this study is to improve the physical and mechaniproperties of local inferior quality wood species by radiation-induced graft polymerization with plastic monomers. The process involves the following: 1) Preparation of sample; 2) Impregnation of sample with the monomers; 3) Irradiation of the impregnated sample with the use of 20,000 curie Co-60 as gamma-source; 4) Drying of irradiated sample to remove the unpolymerized monomer. Experimentation on different wood species were undertaken and the results given. From the results obtained, it can be concluded that the monomers systems MMA, MMA-USP, and styrene-USP are suitable for graft polymerization with the wood species almon, apitong, bagtikan, mayapis, red lauan, and tanguile. This is shown by their maximum conversion value which range from 86% to 96% with the optimum dose range of 1 to 2 Mrads. However, in the application of WPC process, properties that are required in a given wood product must be considered, thus aid in the selection of the monomer system to be used with a particular wood species. Some promising applications of WPC is in the manufacture of picker sticks, shuttles, and bobbins for the textile industry. However, there is a need for a pilot plant scale study so that an economic assessment of the commercial feasibility of this process can be made

  13. Wood Storks of the Birdsville Colony and swamps of the Savannah River Site: General overview of research findings, 1983--1990

    International Nuclear Information System (INIS)

    Coulter, M.C.

    1993-02-01

    The population of Wood Storks (Mycteria americana) that breeds in the United States has decreased from an estimated 20,000 breeding pairs in 1930 to just under 5,000 pairs in 1980. Since 1980, the number has remained relatively stable, fluctuating between 3,500 and 5,500 breeding pairs. The decline prompted the US Fish and Wildlife Service (USFWS) to list the United States population of Wood Storks as endangered in 1984. When the US Department of Energy (USDOE) decided to restart L-Reactor on the Savannah River Site (SRS), there was concern that when the reactor was restarted, cooling water flowing into the Steel Creek Delta would raise the water level and the area would become too deep for foraging storks. The potential loss of this area to storks was important because storks had been observed foraging in the Steel Creek Delta. The USDOE began consultation with the USFWS in April, 1984, and the USDOE subsequently agreed to develop and maintain alternative foraging habitat to replace the potential loss. In order to design and manage the alternate foraging ponds as effectively as possible, it was necessary to understand aspects of the biology of the storks, the characteristics of their foraging sites and the patterns of their use of the SRSS. Results are described

  14. 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)

  15. 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)

  16. Black hole levitron

    International Nuclear Information System (INIS)

    Arsiwalla, Xerxes D.; Verlinde, Erik P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.'s multicenter supersymmetric black hole solutions provides a supergravity description of such backgrounds within which a black hole can be trapped within a confined volume. This construction is realized by solving for a levitating black hole over a magnetic dipole base. We comment on how such a construction is akin to a mechanical levitron.

  17. Role of construction debris in release of copper, chromium, and arsenic from treated wood structures

    Science.gov (United States)

    Stan T. Lebow; Steven A. Halverson; Jeffrey J. Morrell; John. Simonsen

    Recent research on the release of wood preservatives from treated wood used in sensitive environments has not considered the potential contribution from construction residues. This study sought to develop leaching rate data for small construction debris and compare those to the release rate from treated wood itself. Western hemlock boards were pressure treated with...

  18. Exposure testing of fasteners in preservative treated wood : gravimetric corrosion rates and corrosion product analyses

    Science.gov (United States)

    Samuel L. Zelinka; Rebecca J. Sichel; Donald S. Stone

    2010-01-01

    Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27oC at 100% relative humidity for 1 year. The...

  19. Controlling moisture content of wood samples using a modified soil-pan decay method

    Science.gov (United States)

    Jerrold E. Winandy; Simon F. Curling; Patricia K. Lebow

    2005-01-01

    In wood, the threshold level below which decay cannot occur varies with species or type of wood product and other factors such as temperature, humidity, and propensity of exposure or service-use to allow rain-induced wetting and subsequent drying. The ability to control wood moisture content (MC) during laboratory decay testing could allow research on the moisture...

  20. Summary of air permeability data from single-hole injection tests in unsaturated fractured tuffs at the Apache Leap Research Site: Results of steady-state test interpretation

    International Nuclear Information System (INIS)

    Guzman, A.G.; Geddis, A.M.; Henrich, M.J.; Lohrstorfer, C.F.; Neuman, S.P.

    1996-03-01

    This document summarizes air permeability estimates obtained from single hole pneumatic injection tests in unsaturated fractured tuffs at the Covered Borehole Site (CBS) within the larger apache Leap Research Site (ALRS). Only permeability estimates obtained from a steady state interpretation of relatively stable pressure and flow rate data are included. Tests were conducted in five boreholes inclined at 45 degree to the horizontal, and one vertical borehole. Over 180 borehole segments were tested by setting the packers 1 m apart. Additional tests were conducted in segments of lengths 0.5, 2.0, and 3.0 m in one borehole, and 2.0 m in another borehole, bringing the total number of tests to over 270. Tests were conducted by maintaining a constant injection rate until air pressure became relatively stable and remained so for some time. The injection rate was then incremented by a constant value and the procedure repeated. The air injection rate, pressure, temperature, and relative humidity were recorded. For each relatively stable period of injection rate and pressure, air permeability was estimated by treating the rock around each test interval as a uniform, isotropic porous medium within which air flows as a single phase under steady state, in a pressure field exhibiting prolate spheroidal symmetry. For each permeability estimate the authors list the corresponding injection rate, pressure, temperature and relative humidity. They also present selected graphs which show how the latter quantities vary with time; logarithmic plots of pressure versus time which demonstrate the importance of borehole storage effects during the early transient portion of each incremental test period; and semilogarithmic plots of pressure versus recovery time at the end of each test sequence

  1. WOOD PROPERTIES AND EFFECT OF WOOD PROPERTIES ON THE WOOD FINISHING

    Directory of Open Access Journals (Sweden)

    Abdulkadir Malkoçoğlu

    2006-04-01

    Full Text Available Wood is basic raw material for furniture and joinery industries with wood structures. Wood is a biological material that has widely different properties depending on species, geographic area where the tree grew, the growth condition, size of the tree at harvest, sawing, and other manufacturing processes. Wood properties have been characterized within two groups as natural and manufacturing factors that effects finishing performance. Grow rate, density, knots, moisture content, extractives and juvenile wood are natural characteristics. Grain orientation, texture, drying and performance expectations are manufacturing characteristics. In this review, the effects of natural and manufacturing characteristics are discussed on the surface finishing performance of wood.

  2. Wood for sound.

    Science.gov (United States)

    Wegst, Ulrike G K

    2006-10-01

    The unique mechanical and acoustical properties of wood and its aesthetic appeal still make it the material of choice for musical instruments and the interior of concert halls. Worldwide, several hundred wood species are available for making wind, string, or percussion instruments. Over generations, first by trial and error and more recently by scientific approach, the most appropriate species were found for each instrument and application. Using material property charts on which acoustic properties such as the speed of sound, the characteristic impedance, the sound radiation coefficient, and the loss coefficient are plotted against one another for woods. We analyze and explain why spruce is the preferred choice for soundboards, why tropical species are favored for xylophone bars and woodwind instruments, why violinists still prefer pernambuco over other species as a bow material, and why hornbeam and birch are used in piano actions.

  3. 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.

  4. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  5. Energy wood procurement in connection with conventional wood procurement; Energiapuun hankinnan organisointi muun puunhankinnan yhteydessae - PUUT02

    Energy Technology Data Exchange (ETDEWEB)

    Maekinen, P. [Finnish Forest Research Institute, Vantaa (Finland)

    2001-07-01

    The research consisted of two sub-projects. The present role of forestry associations in procurement of energy wood was investigated in the first sub- project. The possibilities and willingness of them to increase the energy wood procurement were also studied. The role of forest machine and forestry service entrepreneurs in procurement of energy wood was investigated in the second sub-project. The effects of energy wood procurement on the operation of the forest machine companies in general were also studied in this sub-project. The sub-project three studied the requirements of the customer companies for the energy wood suppliers. All the material of the sub-projects was collected by personal inquiries. According to the executive directors of the forestry associations the role of the forestry associations in energy wood procurement varied between a by-stander and active participant. Active forestry associations announced the companies for stands available for cutting. They told also that they directed the harvesting to correct sites and deliver stems at the roadside. The role of the forestry association was emphasised especially when the associations on the basis of a letter of attorney carried out the timber trade. It was estimated that in the near future the operation of forest machine entrepreneurs in harvesting of energy wood would increase significantly. From the employment and turnover point of view the role of harvesting of energy wood was not seen as a significant matter. On the other hand, that harvesting of energy wood impede the harvesting of commercial timber was seen as a more significant matter. In the future the end-users of energy wood would like to have more competition in the energy wood markets. However, the energy wood suppliers were desired to be relative large so that the reliability of deliveries could be ensured. Simultaneously as the end-users wanted to decrease the price of forest chips, the machine entrepreneurs estimated the price to

  6. Methane from wood

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-15

    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)

  7. 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)

  8. Inventory of usage pattern for wood burning appliances

    International Nuclear Information System (INIS)

    Cooper, David; Joeborn, Inger; Sjoedin, Aake; Munkhammar, Inger; Gustavsson, Lennart

    2005-02-01

    The Swedish Environmental Research Institute (IVL) in co-operation with the Swedish National Testing and Research Institute (SP) and Statistics Sweden (SCB) have investigated the use of domestic wood burning for wood stoves and open fireplaces. The results from a closer examination of existing national energy statistics for residential heating has enabled a division of the average consumption of firewood for each house by the category 'fireplace for open fire' and 'tiled stove/heating stove/fireplace for wood'. The estimation of emissions can therefore be improved by differentiating emission factors for different wood stoves and open fireplaces. Today, only one emission factor is used. An insight into general firing procedures, wood storage routines etc. was investigated using a questionnaire for the Teleborg area of the city Vaexjoe. The results of this study provide a foundation for further work, which will subsequently enable improvements for emission inventories on small-scale biomass combustion from household appliances

  9. Wood energy-commercial applications

    Science.gov (United States)

    Kennel, R. P.

    1978-01-01

    Wood energy is being widely investigated in many areas of the country because of the many obvious benefits of wood fuel such as the low price per million Btus relative to coal, oil, and gas; the wide availability of noncommercial wood and the proven ability to harvest it; established technology which is reliable and free of pollution; renewable resources; better conservation for harvested land; and the potential for jobs creation. The Southeastern United States has a specific leadership role in wood energy based on its established forest products industry experience and the potential application of wood energy to other industries and institutions. Significant questions about the widespread usage of wood energy are being answered in demonstrations around the country as well as the Southeast in areas of wood storage and bulk handling; high capitalization costs for harvesting and combustion equipment; long term supply and demand contracts; and the economic feasibility of wood energy outside the forest products industry.

  10. 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.

  11. 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...

  12. Power generation from waste wood

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, H

    1980-04-18

    Since the energy crisis, power generation from waste wood has become increasingly important. The most profitable way to use waste wood in woodworking plants with an annual production of 100 to 150,000 m/sup 3/ solid measure of wood chips and bark is by combustion and thermal energy recovery. In plants with an annual production of 10,000 m/sup 3/ solid measure of wood chips and bark, electric power generation is a suitable application.

  13. Structure and function of wood

    Science.gov (United States)

    Alex Wiedenhoeft

    2010-01-01

    Wood is a complex biological structure, a composite of many chemistries and cell types acting together to serve the needs of a living plant. Attempting to understand wood in the context of wood technology, we have often overlooked the key and basic fact that wood evolved over the course of millions of years to serve three main functions in plants― conduction of water...

  14. A novel calibration algorithm for five-hole pressure probe

    African Journals Online (AJOL)

    user

    Five-hole probes are used to measure the three components of velocity, inflow ... centre hole pressure labeled as 5. P and the off-axis holes labeled as 1. P , 2. P , 3 ..... of this study and is doing research in the flow control group of the institute.

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

    African Journals Online (AJOL)

    The intent of this article is to demonstrate how wood waste called sawdust or wood flour can be transformed by plastic moulding machine into items of economic value. Wood flour is wood reduced to very fine particle form. It can be waste product from saw mills, wood working plants or produced from selected dry wood by ...

  16. Hole history, rotary hole DC-3

    International Nuclear Information System (INIS)

    1977-10-01

    Purpose of hole DC-3 was to drill into the Umtanum basalt flow using both conventional rotary and core drilling methods. The borehole is to be utilized for geophysical logging, future hydrological testing, and the future installation of a borehole laboratory for long-term pressure, seismic, and moisture migration or accumulation recording in the Umtanum basalt flow in support of the Basalt Waste Isolation Program. Hole DC-3 is located east of the 200 West barricaded area on the Hanford reservation

  17. 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

  18. 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...

  19. Macrophotographic wood atlas of Annonaceae.

    NARCIS (Netherlands)

    Koek-Noorman, J.; Westra, L.I.T.

    2012-01-01

    In this article, a general description of the microscopic wood anatomy of Annonaceae is given. We provide a description of the wood anatomical features of the family and of all subfamilies and tribes, all from material in the Utrecht Wood collection. Hand-lens images can be an important help in

  20. Dimensional Stabilization of Wood In Use

    Science.gov (United States)

    R. M. Rowell; R. L. Youngs

    1981-01-01

    Many techniques have been devised to reduce the tendency of wood to change dimensions in contact with moisture. Treatments such as cross-lamination, water-resistant coatings, hygroscopicity reduction, crosslinking, and bulking are reviewed and recommendations for future research are given.

  1. Incorporating biopulping technology into wood yard operations

    Science.gov (United States)

    Gary M. Scott; Eric. Horn; Masood. Akhtar; Ross E. Swaney; Michael J. Lentz; David F. Shipley

    1998-01-01

    Biopulping is the treatment of wood chips and other lignocellulosic materials with lignin-degrading fungi prior to pulping. Ten years of industry-sponsored research has demonstrated the technical feasibility of the technology for mechanical pulping at a laboratory scale. Two 50-ton outdoor chip pile trials recently conducted at the USDA Forest Service, Forest Products...

  2. Low-NO{sub x}, wood chip combustion

    Energy Technology Data Exchange (ETDEWEB)

    Saastamoinen, J.; Oravainen, H.; Haemaelaeinen, J.; Paakkinen, K. [VTT Energy, Jyvaeskylae (Finland)

    1997-10-01

    The regulations for nitrogen oxide emissions vary in different countries, but the general trend in the future will probably be that the emissions limits will be lowered also for wood combustion plants, which are small or medium size units. Thus, the development of wood chip burning furnaces (grate furnaces, fluidized bed combustors, stoker furnaces) with lower nitrogen oxide emissions, is important. The wood used in the combustor, its particle size, moisture and fuel properties (nitrogen content) affect the nitrogen emissions. The nitrogen oxide release is also much affected by the design and operation of the combustor (air staging, fuel air preheat, flue gas circulation, air to fuel mass ratio). The fate of nitrogen compounds originally in the virgin wood depends much on the design of the combustor system and by proper planning it is possible to reduce the emission of nitrogen oxides. Basic knowledge of the release of nitrogen compounds from single wood particles is attained. The release of gaseous nitrogen compounds from wood particles during pyrolysis and combustion is studied experimentally and by modelling. Nitrogen release is studied experimentally by two ways, by analysing the gas and by quenching the particle and analysing the char residue. Formation of nitrogen oxide emissions in a fuel bed is studied by modelling and by combustion experiments with a pot furnace. This research gives general information of nitrogen oxide formation in wood bunting especially in fixed beds. The development of a horizontal stoker burner for wood chips with low emissions is the practical aim of the research. (orig.)

  3. 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

  4. Black and white holes

    International Nuclear Information System (INIS)

    Zeldovich, Ya.; Novikov, I.; Starobinskij, A.

    1978-01-01

    The theory is explained of the origination of white holes as a dual phenomenon with regard to the formation of black holes. Theoretically it is possible to derive the white hole by changing the sign of time in solving the general theory of relativity equation implying the black hole. The white hole represents the amount of particles formed in the vicinity of a singularity. For a distant observer, matter composed of these particles expands and the outer boundaries of this matter approach from the inside the gravitational radius Rsub(r). At t>>Rsub(r)/c all radiation or expulsion of matter terminates. For the outside observer the white hole exists for an unlimited length of time. In fact, however, it acquires the properties of a black hole and all processes in it cease. The qualitative difference between a white hole and a black hole is in that a white hole is formed as the result of an inner quantum explosion from the singularity to the gravitational radius and not as the result of a gravitational collapse, i.e., the shrinkage of diluted matter towards the gravitational radius. (J.B.)

  5. Black and white holes

    Energy Technology Data Exchange (ETDEWEB)

    Zeldovich, Ya; Novikov, I; Starobinskii, A

    1978-07-01

    The theory is explained of the origination of white holes as a dual phenomenon with regard to the formation of black holes. Theoretically it is possible to derive the white hole by changing the sign of time in solving the general theory of relativity equation implying the black hole. The white hole represents the amount of particles formed in the vicinity of a singularity. For a distant observer, matter composed of these particles expands and the outer boundaries of this matter approach from the inside the gravitational radius R/sub r/. At t>>R/sub r//c all radiation or expulsion of matter terminates. For the outside observer the white hole exists for an unlimited length of time. In fact, however, it acquires the properties of a black hole and all processes in it cease. The qualitative difference between a white hole and a black hole is in that a white hole is formed as the result of an inner quantum explosion from the singularity to the gravitational radius and not as the result of a gravitational collapse, i.e., the shrinkage of diluted matter towards the gravitational radius.

  6. Primary black holes

    International Nuclear Information System (INIS)

    Novikov, I.; Polnarev, A.

    1981-01-01

    Proves are searched for of the formation of the so-called primary black holes at the very origin of the universe. The black holes would weigh less than 10 13 kg. The formation of a primary black hole is conditional on strong fluctuations of the gravitational field corresponding roughly to a half of the fluctuation maximally permissible by the general relativity theory. Only big fluctuations of the gravitational field can overcome the forces of the hot gas pressure and compress the originally expanding matter into a black hole. Low-mass black holes have a temperature exceeding that of the black holes formed from stars. A quantum process of particle formation, the so-called evaporation takes place in the strong gravitational field of a black hole. The lower the mass of the black hole, the shorter the evaporation time. The analyses of processes taking place during the evaporation of low-mass primary black holes show that only a very small proportion of the total mass of the matter in the universe could turn into primary black holes. (M.D.)

  7. 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.

  8. 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)

  9. Dark Dark Wood

    DEFF Research Database (Denmark)

    2017-01-01

    2017 student Bachelor film. Synopsis: Young princess Maria has had about enough of her royal life – it’s all lesson, responsibilities and duties on top of each other, every hour of every day. Overwhelmed Maria is swept away on an adventure into the monster-filled dark, dark woods. During 2017...

  10. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

    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.

  11. Sweetgum - an American wood

    Science.gov (United States)

    C. B. Briscoe

    1973-01-01

    Sweetgum grows throughout most of the eastern United States and sporadically throughout Mexico and Central America. The wood is moderately heavy, even-textured, and it machines moderately well. It is used for a variety of purposes, with furniture, plywood, containers, and pulp absorbing the most volume. Growth is good, but supplies are slowly diminishing because the...

  12. 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.

  13. Handling wood shavings

    Energy Technology Data Exchange (ETDEWEB)

    1974-09-18

    Details of bulk handling equipment suitable for collection and compressing wood waste from commercial joinery works are discussed. The Redler Bin Discharger ensures free flow of chips from storage silo discharge prior to compression into briquettes for use as fuel or processing into chipboard.

  14. Environmental issues: New techniques for managing and using wood fuel ash

    Energy Technology Data Exchange (ETDEWEB)

    Fehrs, J.E.; Donovan, C.T. [C.T. Donovan Associates, Inc., Burlington, VT (United States)

    1993-12-31

    Continued research and development of environmentally-acceptable and cost-effective end uses for wood ash is having a significant affect on the ability to use wood and wood waste for fuel. This is particularly true for ash resulting from treated wood combustion. Concerns about the contents of ash from wood containing paint, stain, preservatives, or other chemicals is one of the largest regulatory barriers to its use as fuel. The purpose of this paper is to: (1) Identify the physical and chemical characteristics of ashes produced from the combustion of untreated and treated wood; (2) Explain the types of {open_quotes}clean, untreated{close_quotes} and {open_quotes}treated{close_quotes} wood that are likely to produce ash that can beneficially used; (3) Describe existing and potential products and end uses for untreated and treated wood ash.

  15. Combustion behaviour of pulverised wood - Numerical and experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Lixin Tao [TPS Termiska Processer AB, Nykoeping (Sweden)

    2002-05-01

    This report presents the experimental results achieved in an on-going project financed by STEM (Energimyndigheten) within the research program 'Gasification and combustion of solid fuels', during the first phase of the project (2001-03-05 to 2002-03-05). The project is a collaboration project between LTH and TPS on combined numerical modelling/experimental investigation on combustion of pulverised wood. Particularly TPS carry out the experimental investigation in a laboratory vertical furnace. During the project, the experimental rig has been developed. The experimental furnace has an inner diameter of 0.25 m and a height of 4 m. A pulverised wood flame is established using an axial burner that is installed on the top of the furnace. Experimental study on a selected pulverised wood with determined size distribution and anisotropy character has been carried out in this furnace. During the experiment, the wall temperatures of the furnace were continuously measured using 8 thermocouples of type K that are installed on the wall with a spacing about 0.5 m. The gas temperatures in the furnace were monitored using 5 fixed suction pyrometers that are placed along the centre of the furnace. At the bottom of the furnace, a fixed gas-sampling probe was installed. The flue gas concentrations were continuously monitored with on-line gas analysers. The extent of combustion was measured through the analysis of sampled gaseous products and condensable solid products. A movable liquid quench probe was used to carry out the gas and solid sampling through a number of sampling holes that are opened along the furnace wall. The quench liquor used is an alkaline water solution containing a small amount of a detergent to dissolve HCN and tar. The quench liquor and solid samples were separated and collected in a knockout pot. The gas was filtered and passed through two bubblers with acidic solution to collect NH{sub 3}. The gas concentrations were then analysed with on-line gas

  16. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  17. Accreting Black Holes

    OpenAIRE

    Begelman, Mitchell C.

    2014-01-01

    I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these ...

  18. Nonextremal stringy black hole

    International Nuclear Information System (INIS)

    Suzuki, K.

    1997-01-01

    We construct a four-dimensional BPS saturated heterotic string solution from the Taub-NUT solution. It is a nonextremal black hole solution since its Euler number is nonzero. We evaluate its black hole entropy semiclassically. We discuss the relation between the black hole entropy and the degeneracy of string states. The entropy of our string solution can be understood as the microscopic entropy which counts the elementary string states without any complications. copyright 1997 The American Physical Society

  19. Naked black holes

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Ross, S.F.

    1997-01-01

    It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces outside the horizon. These black holes are charged and near extremality, and exist in a wide class of theories including string theory. The implications for cosmic censorship and the black hole information puzzle are discussed. copyright 1997 The American Physical Society

  20. Wood construction under cold climate

    DEFF Research Database (Denmark)

    Wang, Xiaodong; Hagman, Olle; Sundqvist, Bror

    2014-01-01

    As wood constructions increasingly use engineered wood products worldwide, concerns arise about the integrity of the wood and adhesives system. The glueline stability is a crucial issue for engineered wood application, especially under cold climate. In this study, Norway spruce (Picea abies...... 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...... specimens need to be tested in further work to more completely present the issue. The EN 301 and EN 302 may need to be specified based on wood species....

  1. Feasibility of biodegradation of pentachlorophenol in scrap wood

    International Nuclear Information System (INIS)

    Beaulieu, G.; Besner, A.; Gilbert, R.; Tetreault, P.; Beaudet, R.; Bisaillon, J. G.; Lepine, F.; Ottou, J. M.; Sansregret, J. L.; Lei, J.

    1998-04-01

    The feasibility of biological treatment of scrap wood impregnated in pentachlorophenol (PCP) was investigated using wood samples impregnated with PCP for biodegradation experiments by the Hydro-Quebec Research Institute (IREQ). IREQ identified the necessity of pre-treating the wood, first by shredding wood poles into wood shavings, followed by mechanical milling of the shavings to obtain wood dust. Biodegradation experiments under anaerobic conditions were performed by the Armand-Frappier Institute by isolating a consortium of bacteria from a mixture of PCP-contaminated soils and a municipal anaerobic sludge that was able to degrade PCP under anaerobic methanogenic conditions at 29 degrees C. A complementary source of carbon was found to be necessary for the bacterial consortium to degrade the PCP. The best PCP degradation results were obtained with an aerobic fixed-film reactor. Aerobic biodegradation tests were performed on liquor extracted from wood dust contaminated with PCP. The anaerobic fixed field reactor was able to completely degrade the PCP extracted from wood dust in less than one day. Aerobic biodegradation was also investigated using microorganisms and fungi. Over a four month experimental period only low concentrations of PCP were found in effluents treated with the aerobic cultures. 117 refs., 38 tabs., 31 figs

  2. EVALUATION OF WOOD PERFORMANCE IN BUILDING CONSTRUCTION THROUGH SYSTEM APPROACH

    Directory of Open Access Journals (Sweden)

    Ricardo Pedreschi

    2005-09-01

    Full Text Available Building construction is considered to be the leading market for the wood industry, in developed and developingcountries. The greatest amount of wood produced in Brazil is consumed as firewood and energy, followed by production of celluloseand third as machined wood. The use of wood from planted forests can be increased. This would lead to a better use of naturalresources, and consequently to an increased sustainability of forest activity in many regions of the country. The performance of woodcan be observed from many different insights: symbolic performance, technical performance and economical performance, conductedby the method of systems approach to architecture. Usages of wood related to the performances of the material, with the redefinitionof parameters of use, elaborating a new culture linked to new technologies were outlined. This work diagnosed the usage of wood inbuilding construction based in system analysis. Through an opinion research related to the acceptation of the use of wood we observethe possibilities of utilization according to physical and mechanical proprieties, aesthetics and appearance performance and postoccupation.According to the results obtained related to the culture and knowledge about the use of wood from planted forest, it canconclude that there is not enough knowledge in this area, and it is, therefore, necessary to create an information system forprofessionals and for people in general.

  3. Breeding for wood quality - a perspective for the future

    CSIR Research Space (South Africa)

    Verryn, SD

    2008-01-01

    Full Text Available A challenge for breeders and wood quality researchers of today is to appropriately respond to a complex environment demanding more productivity, higher quality, and a quicker adaptation of their crops to rapid changes. This is mirrored...

  4. Potential of Reinforced Indonesian Glulam Beams Using Grade I (Bengkirai, Grade II (Kamper, Grade III (Nyatoh Woods for Use in Structural Wood Design

    Directory of Open Access Journals (Sweden)

    Saptahari Sugiri

    2016-05-01

    Full Text Available Wood is a natural resource that is renewable and available in various species in tropical countries. Its abundancy in nature makes it easy to obtain, thus making it a nature friendly material for use in construction. Indonesia is the most important source of tropical wood in the world after Brazil, making the use of wood for structural elements very desirable. It is estimated that 4000 different varieties of wood exist in Indonesia. This estimate is based on the herbarium species collected by the Forestry Research Institute, currently counting nearly 4000 types of trees with a diameter of more than 40 cm. In the Indonesian wood structure code, the strength of woods is divided into 3 grades (grade I, II and III. This paper presents an evaluation of the mechanical properties of glulam wood sourced from native Indonesian timber: Bengkirai wood (grade I, Kamper wood (grade II, and Nyatoh wood (grade III, thus proving the potential for Indonesian wood as industrial structural elements in wooden constructions.

  5. FLEXURAL TESTING OF WOOD-CONCRETE COMPOSITE BEAM MADE FROM KAMPER AND BANGKIRAI WOOD

    Directory of Open Access Journals (Sweden)

    Fengky Satria Yoresta

    2015-07-01

    Full Text Available Certain wood has a tensile strength that almost equal with steel rebar in reinforced concrete beams. This research aims to understand the capacity and flexural behavior of concrete beams reinforced by wood (wood-concrete composite beam. Two different types of beams based on placement positions of wood layers are proposed in this study. Two kinds of wood used are consisted of Bangkirai (Shorea laevifolia and Kamper (Cinnamomum camphora, meanwhile the concrete mix ratio for all beams is 1 cement : 2 fine aggregates : 3 coarse aggregates. Bending test is conducted by using one-point loading method. The results show that composite beam using Bangkirai wood is stronger than beams using Kamper wood. More thicker wood layer in tensile area will increase the flexural strength of beams. Crack patterns identified could be classified into flexural cracks, shear cracks, and split on wood layer   Beberapa jenis kayu tertentu memiliki kekuatan tarik yang hampir sama dengan tulangan baja pada balok beton bertulang. Penelitian ini bertujuan memahami kapasitas dan perilaku lentur balok beton bertulang yang diperkuat menggunakan kayu (balok komposit beton-kayu. Dua tipe balok yang berbeda berdasarkan posisi penempatan kayu digunakan dalam penelitian ini. Dua jenis kayu yang digunakan adalah kayu Bangkirai (Shorea laevifolia and Kamper (Cinnamomum camphora, sementara itu rasio campuran beton untuk semua balok menggunakan perbandingan 1 semen : 2 agregat halus : 3 agregat kasar. Pengujian lentur dilakukan menggunakan metode one-point loading. Hasil penelitian menunjukkan bahwa balok komposit dengan kayu Bangkirai lebih kuat dibandingkan balok dengan kayu Kamper. Semakin tebal lapisan kayu yang berada di daerah tarik akan meningkatkan kekuatan lentur balok. Pola kerusakan yang teridentifikasi dapat diklasifikasikan menjadi retak lentur, retak geser, dan pecah pada kayu REFERENCES Boen T. (2010. Retrofitting Simple Buildings Damaged by Earthquakes. World Seismic

  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. 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.

  8. 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)

  9. Radioactivity of wood ash

    International Nuclear Information System (INIS)

    Rantavaara, A.; Moring, M.

    2000-01-01

    STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg -1 , in decreasing order: 137 Cs, 40 K, 90 Sr, 210 Pb, 226 Ra, 232 Th, 134 Cs, 235 U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and 210 Pb was hardly detectable. The NH 4 Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

  10. Method of stabilizing wood

    International Nuclear Information System (INIS)

    Pesek, M.; Dedek, V.; Plander, E.

    1975-01-01

    Wood is impregnated with vinyl monomers in a solution of organic solvents and in the presence of a swelling agent. The impregnation mixture contains a diolefinic hydrocarbon and/or a solid chlorinated or bromated compound with the melting point exceeding 30 degC and less than 10 % of an organosilicon compound. Polymerization is effected by ionizing radiation and a subsequent action of temperature in a range of 40 to 150 JegC. (B.S.)

  11. Black hole Berry phase

    NARCIS (Netherlands)

    de Boer, J.; Papadodimas, K.; Verlinde, E.

    2009-01-01

    Supersymmetric black holes are characterized by a large number of degenerate ground states. We argue that these black holes, like other quantum mechanical systems with such a degeneracy, are subject to a phenomenon which is called the geometric or Berry’s phase: under adiabatic variations of the

  12. Black holes are warm

    International Nuclear Information System (INIS)

    Ravndal, F.

    1978-01-01

    Applying Einstein's theory of gravitation to black holes and their interactions with their surroundings leads to the conclusion that the sum of the surface areas of several black holes can never become less. This is shown to be analogous to entropy in thermodynamics, and the term entropy is also thus applied to black holes. Continuing, expressions are found for the temperature of a black hole and its luminosity. Thermal radiation is shown to lead to explosion of the black hole. Numerical examples are discussed involving the temperature, the mass, the luminosity and the lifetime of black mini-holes. It is pointed out that no explosions corresponding to the prediction have been observed. It is also shown that the principle of conservation of leptons and baryons is broken by hot black holes, but that this need not be a problem. The related concept of instantons is cited. It is thought that understanding of thermal radiation from black holes may be important for the development of a quantified gravitation theory. (JIW)

  13. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  14. Quantum black holes

    OpenAIRE

    Hooft, G. 't

    1987-01-01

    This article is divided into three parts. First, a systematic derivation of the Hawking radiation is given in three different ways. The information loss problem is then discussed in great detail. The last part contains a concise discussion of black hole thermodynamics. This article was published as chapter $6$ of the IOP book "Lectures on General Relativity, Cosmology and Quantum Black Holes" (July $2017$).

  15. Black hole levitron

    NARCIS (Netherlands)

    Arsiwalla, X.D.; Verlinde, E.P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.’s multicenter

  16. Newborn Black Holes

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Scientists using NASA's Swift satellite say they have found newborn black holes, just seconds old, in a confused state of existence. The holes are consuming material falling into them while somehow propelling other material away at great speeds. "First comes a blast of gamma rays followed by intense pulses of x-rays. The energies involved are much…

  17. A reassessment of carbon content in wood: variation within and between 41 North American species

    International Nuclear Information System (INIS)

    Lamlom, S.H.; Savidge, R.A.

    2003-01-01

    At present, 50% (w/w) carbon is widely promulgated as a generic value for wood; however, the literature yields few data and indicates that very little research has actually been done. C contents in heartwood of forty-one softwood and hardwood species were determined. C in kiln-dried hardwood species ranged from 46.2% to 49.97% (w/w), in conifers from 47.21% to 55.2%. The higher C in conifers agrees with their higher lignin content (∼30%, versus ∼20% for hardwoods). Wood-meal samples drilled from discrete early wood and late wood zones of seven of the forty-one species were also investigated. C contents of early woods were invariably higher than those in corresponding late woods, again in agreement with early wood having higher lignin content. Further investigation was made into freshly harvested wood of some species to determine how much volatile C is present, comparing oven-dried wood meal with wood meal dried at ambient temperature over a desiccant. C contents of oven-dried woods were significantly lower, indicating that all past data on C content in oven-dried or kiln-dried woods may be inaccurate in relation to the true C content of forests. We conclude that C content varies substantially among species as well as within individual trees. Clearly, a 50% generic value is an oversimplification of limited application in relation to global warming and the concept of 'carbon credits'. (author)

  18. 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.)

  19. Wood torrefaction. Pilot tests and utilisation prospects

    Energy Technology Data Exchange (ETDEWEB)

    Wilen, C.; Jukola, P.; Jarvinen, T.; Sipila, K. [VTT Technical Reseach Centre of Finland, Espoo (Finland); Verhoeff, F.; Kiel, J. [Energy research Centre of the Netherlands, LE Petten (Netherlands)

    2013-09-15

    The research project 'Torrefaction of woody biomasses as energy carriers for the European markets' was carried out within the Tekes BioRefine programme in 2010-2012 and was coordinated by VTT. The main objective of the project was to create a discussion platform and collate basic information for the Finnish industrial stakeholders involved in developing torrefaction technology or planning to include torrefied biomass in their fuel supply for energy production. Given the availability of torrefaction pilot facilities in Europe, it was decided at an early phase of the national torrefaction research project not to build and operate separate pilot equipment, and thus save time and money. Experimental research was conducted in cooperation with ECN, The Netherlands. Finnish wood chips and crushed forest residue were tested at different torrefaction temperatures in the PATRIG torrefaction test rig with great success, and large quantities of torrefied wood chips and pellets were produced. CFD simulation work was carried out at VTT to investigate the feasibility of torrefied fuels to replace part of the coal. From the combustion point of view it seems feasible to replace coal by torrefied wood biomass with shares up to 50% by weight. Basic, small-scale experiments were carried out to compare torrefied wood pellets with conventional wood and straw pellets with regard to their handling and storage properties. The experiments showed that the torrefied pellets are clearly more hydrophobic than wood and straw pellets and do not disintegrate completely on exposure to water. A study on dust explosion and self-ignition characteristics indicated that the torrefied dust does not differ significantly from the normal biomass dust, but is clearly more reactive than coal dust. Commercial development of torrefaction is currently in its early phase. The current general view is that most of the demonstration plants have technical problems, which have delayed their commercial

  20. Postfire Succession of Ants (Hymenoptera: Formicidae) Nesting in Dead Wood of Northern Boreal Forest.

    Science.gov (United States)

    Boucher, Philippe; Hébert, Christian; Francoeur, André; Sirois, Luc

    2015-10-01

    Dead wood decomposition begins immediately after tree death and involves a large array of invertebrates. Ecological successions are still poorly known for saproxylic organisms, particularly in boreal forests. We investigated the use of dead wood as nesting sites for ants along a 60-yr postfire chronosequence in northeastern coniferous forests. We sampled a total of 1,625 pieces of dead wood, in which 263 ant nests were found. Overall, ant abundance increased during the first 30 yr after wildfire, and then declined. Leptothorax cf. canadensis Provancher, the most abundant species in our study, was absent during the first 2 yr postfire, but increased steadily until 30 yr after fire, whereas Myrmica alaskensis Wheeler, second in abundance, was found at all stages of succession in the chronosequence. Six other species were less frequently found, among which Camponotus herculeanus (Linné), Formica neorufibarbis Emery, and Formica aserva Forel were locally abundant, but more scarcely distributed. Dead wood lying on the ground and showing numerous woodborer holes had a higher probability of being colonized by ants. The C:N ratio was lower for dead wood colonized by ants than for noncolonized dead wood, showing that the continuous occupation of dead wood by ants influences the carbon and nitrogen dynamics of dead wood after wildfire in northern boreal forests. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Lifshitz topological black holes

    International Nuclear Information System (INIS)

    Mann, R.B.

    2009-01-01

    I find a class of black hole solutions to a (3+1) dimensional theory gravity coupled to abelian gauge fields with negative cosmological constant that has been proposed as the dual theory to a Lifshitz theory describing critical phenomena in (2+1) dimensions. These black holes are all asymptotic to a Lifshitz fixed point geometry and depend on a single parameter that determines both their area (or size) and their charge. Most of the solutions are obtained numerically, but an exact solution is also obtained for a particular value of this parameter. The thermodynamic behaviour of large black holes is almost the same regardless of genus, but differs considerably for small black holes. Screening behaviour is exhibited in the dual theory for any genus, but the critical length at which it sets in is genus-dependent for small black holes.

  2. 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)

  3. Preliminary studies of Brazilian wood using different radioisotopic sources

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Gilberto; Silva, Leonardo Gondim de Andrade e, E-mail: gcarval@ipen.br, E-mail: ftgasilva@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Due to availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instrument; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere with the growth of trees. This behavior explains why average physical-chemical properties are important when wood is studied. The majority of researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties of wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: 'freijo', 'jequetiba', 'muiracatiara' and 'ipe'. For wood density determination by non-conventional method, Am-241, Ba-133 and Cs-137 radioisotopic sources; a NaI scintillation detector and a counter were used. The results demonstrated this technique to be quick and accurate. By considering the nuclear parameters obtained as half value layers and linear absorption coefficients, Cs-137 radioisotopic source demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. (author)

  4. Urban Wood Waste Resource Assessment; TOPICAL

    International Nuclear Information System (INIS)

    Wiltsee, G.

    1998-01-01

    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

  5. Bridging the gaps: An overview of wood across time and space in diverse rivers

    Science.gov (United States)

    Wohl, Ellen

    2017-02-01

    Nearly 50 years of research focused on large wood (LW) in rivers provide a basis for understanding how wood enters rivers; how wood decays, breaks, and is transported downstream; and how at least temporarily stable wood influences channel geometry, fluxes of water, sediment, and organic matter, and the abundance and diversity of aquatic and riparian organisms. Field-based studies have led to qualitative conceptual models and to numerical stimulations of river processes involving wood. Numerous important gaps remain, however, in our understanding of wood dynamics. The majority of research on wood in rivers focuses on small- to medium-sized rivers, defined using the ratio of wood piece size to channel width as channels narrower than the locally typical wood-piece length (small) and slightly narrower than the longer wood pieces present (medium). Although diverse geographic regions and biomes are represented by one or a few studies in each region, the majority of research comes from perennial rivers draining temperate conifer forests. Regional syntheses most commonly focus on the Pacific Northwest region of North America where most of these studies originate. Consequently, significant gaps in our understanding include lack of knowledge of wood-related processes in large rivers, dryland rivers, and rivers of the high and low latitudes. Using a wood budget as an organizing framework, this paper identifies other gaps related to wood recruitment, transport, storage, and how beavers influence LW dynamics. With respect to wood recruitment, we lack information on the relative importance of mass tree mortality and transport of buried or surficial downed wood from the floodplain into the channel in diverse settings. Knowledge gaps related to wood transport include transport distances of LW and thresholds for LW mobility in small to medium rivers. With respect to wood storage, we have limited data on longitudinal trends in LW loads within unaltered large and great rivers and on

  6. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    mountage types (ply wood, cartoon made, Banana leaf, pl leaf montages) and ... at Melkassa Agricultural Research Center in the sericulture ry during 2011-2013 ..... (2009) also study qualitative improvement in terms of economic gained by.

  7. The wood energy in France

    International Nuclear Information System (INIS)

    Douard, F.; Oremus, Y.; Garsault-Fabbi, A.

    2007-01-01

    The program law fixing the energy policy (POPE Law of the 13 july 2005) fixes an objective of 50% of growth for the renewable heat. As this renewable heat is today generated by the biomass, it seems necessary to adjust all the efforts on this sector. This document proposes to takes stock on the wood energy in France. It presents the wood fuels, an evaluation of the Wood-Energy Plan decided by the ADEME in 2000, the wood heat networks, and some example of installations. (A.L.B.)

  8. Utilization of the irradiation holes in the core at HANARO

    International Nuclear Information System (INIS)

    Lee, Shoong Sung; Ahn, Guk Hoon

    2008-01-01

    HANARO is a multipurpose research reactor. The three hexagonal and four circular holes are reserved for the irradiation tests in the core. Twenty holes including two NTD(Neutron Transmutation Doping) holes, a LH(Large Hole) and NAA holes are located in the reflector tank. These hole have been used for radioisotope production, material and fuel irradiation tests, beam application research and neutron activation analysis. In the initial stage of normal operation, the using time of irradiation holes located in the core was less the 40% of the reactor operation day. To raise utilization of irradiation holes, the equipment and facilities have been developed such as various capsules. Another area for increasing the utilization of HANARO was the fuel irradiation tests to develop the new fuels. Various fuel irradiation tests have been performed. Recently, the usage time of the irradiation holes in the core was more than 90% of the reactor operation day. If the FTL starts an irradiation service, the irradiation holes in the core will be fully used. In this paper describes the status of utilization of irradiation holes in the core

  9. Entropy of quasiblack holes

    International Nuclear Information System (INIS)

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2010-01-01

    We trace the origin of the black hole entropy S, replacing a black hole by a quasiblack hole. Let the boundary of a static body approach its own gravitational radius, in such a way that a quasihorizon forms. We show that if the body is thermal with the temperature taking the Hawking value at the quasihorizon limit, it follows, in the nonextremal case, from the first law of thermodynamics that the entropy approaches the Bekenstein-Hawking value S=A/4. In this setup, the key role is played by the surface stresses on the quasihorizon and one finds that the entropy comes from the quasihorizon surface. Any distribution of matter inside the surface leads to the same universal value for the entropy in the quasihorizon limit. This can be of some help in the understanding of black hole entropy. Other similarities between black holes and quasiblack holes such as the mass formulas for both objects had been found previously. We also discuss the entropy for extremal quasiblack holes, a more subtle issue.

  10. ULTRAMASSIVE BLACK HOLE COALESCENCE

    International Nuclear Information System (INIS)

    Khan, Fazeel Mahmood; Holley-Bockelmann, Kelly; Berczik, Peter

    2015-01-01

    Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC 1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the large SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC 1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gravitational wave emission dominates, and the black holes coalesce in a mere few Myr. Curiously, these extremely massive binaries appear to nearly bypass the three-body scattering evolutionary phase. Our study suggests that in this extreme case, SMBH coalescence is governed by dynamical friction followed nearly directly by gravitational wave emission, resulting in a rapid and efficient SMBH coalescence timescale. We discuss the implications for gravitational wave event rates and hypervelocity star production

  11. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan

    2013-01-01

    Black holes, once just fascinating theoretical predictions of how gravity warps space-time according to Einstein's theory, are now generally accepted as astrophysical realities, formed by post-supernova collapse, or as supermassive black holes mysteriously found at the cores of most galaxies, powering active galactic nuclei, the most powerful objects in the universe. Theoretical understanding has progressed in recent decades with a wider realization that local concepts should characterize black holes, rather than the global concepts found in textbooks. In particular, notions such as trapping h

  12. Eucalyptus grandis AND Eucalyptus dunnii USE FOR WOOD-CEMENT PANELS MANUFACTURING

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2008-03-01

    Full Text Available This research evaluated the potential use of Eucalyptus grandis and Eucalyptus dunnii wood for wood-cement panelsmanufacturing. The boards were manufactured at the density of 1,20 g/cm³, using portland cement as mineral bonding and woodfurnish without treatment, treated in cold water and hot water. The wood furnish of Pinus taeda was used as control. The resultsindicated that it is not necessary to treat E. grandis and E. dunni wood for wood-cement board manufacturing. In relation to woodspecies, the board manufactured with E. dunnii showed lower values of mechanical properties. However, boards manufactured of E.grandis wood showed satisfactory results in comparison to boards of P. taeda and the referenced values of BISON process and otherproducts cited in the pertnent literature, indicating the high potential for wood-cement board manufacture of this tree species.

  13. Survival, growth, wood basic density and wood biomass of seven ...

    African Journals Online (AJOL)

    A performance comparison of seven-year-old individuals of 13 Casuarina species/provenances in terms of survival, growth (diameter, height and volume), wood basic density and wood biomass was undertaken at Kongowe, Kibaha, Tanzania. The trial was laid out using a randomised complete block design with four ...

  14. 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.

  15. 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

  16. Granulated wood ash to forest soil - Ecological effects

    International Nuclear Information System (INIS)

    Rosen, K.; Eriksson, H.; Clarholm, M.; Lundkvist, H.; Rudebeck, A.

    1993-01-01

    This report describes research concerning ecological effects of wood ash recycling to forest soils. The main part of the minerals in the wood fuels are retained in the ashes after combustion. By returning the ashes back to the cleared forest areas, the mineral losses can be reduced. Adding ashes and limestone is a method to vitalize acidified forest soils and restore the production capacity. 48 refs, 26 figs, 8 tabs

  17. Impacts of traditional architecture on the use of wood as an element of facade covering in Serbian contemporary architecture

    Directory of Open Access Journals (Sweden)

    Ivanović-Šekularac Jelena

    2011-01-01

    Full Text Available The world trend of re-use of wood and wood products as materials for construction and covering of architectural structures is present not only because of the need to meet the aesthetic, artistic and formal requirements or to seek inspiration in the return to the tradition and nature, but also because of its ecological, economic and energetic feasibility. Furthermore, the use of wood fits into contemporary trends of sustainable development and application of modern technical and technological solutions in the production of materials, in order to maintain a connection to nature, environment and tradition. In this study the author focuses on wood and wood products as an element of facade covering on buildings in our country, in order to extend knowledge about possibilities and limitations of their use and create a base for their greater and correct application. The subject of this research is to examine the application of wood and wood products as an element covering the exterior in combination with other materials applied in our traditional and contemporary homes with the emphasis on functional, representational art and the various possibilities of wood. In this study all the factors that affect the application of wood and wood products have been analyzed and the conclusions have been drawn about the manner of their implementation and the types of wood and wood products protection. The development of modern technological solutions in wood processing led to the production of composite materials based on wood that are highly resistant, stable and much longer lasting than wood. Those materials have maintained in an aesthetic sense all the characteristics of wood that make it unique and inimitable. This is why modern facade coating based on wood should be applied as a facade covering in the exterior of modern architectural buildings in Serbia, and the use wood reduced to a minimum.

  18. Black Holes Have Simple Feeding Habits

    Science.gov (United States)

    2008-06-01

    The biggest black holes may feed just like the smallest ones, according to data from NASA’s Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes. The conclusion comes from a large observing campaign of the spiral galaxy M81, which is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed. In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way. Using these new observations and a detailed theoretical model, a research team compared the properties of M81's black hole with those of stellar mass black holes. The results show that either big or little, black holes indeed appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. AnimationMulti-wavelength Images of M81 One of the implications of Einstein's theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects. "This confirms that the feeding patterns for black holes of different sizes can be very similar," said Sera Markoff of the Astronomical Institute, University of Amsterdam in the Netherlands, who led the study

  19. Wood-related occupations, wood dust exposure, and sinonasal cancer.

    Science.gov (United States)

    Hayes, R B; Gerin, M; Raatgever, J W; de Bruyn, A

    1986-10-01

    A case-control study was conducted to examine the relations between type of woodworking and the extent of wood dust exposure to the risks for specific histologic types of sinonasal cancer. In cooperation with the major treatment centers in the Netherlands, 116 male patients newly diagnosed between 1978 and 1981 with primary malignancies of epithelial origin of this site were identified for study. Living controls were selected from the municipal registries, and deceased controls were selected from the national death registry. Interviews were completed for 91 (78%) cases and 195 (75%) controls. Job histories were coded by industry and occupation. An index of exposure was developed to classify the extent of occupational exposure to wood dust. When necessary, adjustment was made for age and usual cigarette use. The risk for nasal adenocarcinoma was elevated by industry for the wood and paper industry (odds ratio (OR) = 11.9) and by occupation for those employed in furniture and cabinet making (OR = 139.8), in factory joinery and carpentry work (OR = 16.3), and in association with high-level wood dust exposure (OR = 26.3). Other types of nasal cancer were not found to be associated with wood-related industries or occupations. A moderate excess in risk for squamous cell cancer (OR = 2.5) was associated with low-level wood dust exposure; however, no dose-response relation was evident. The association between wood dust and adenocarcinoma was strongest for those employed in wood dust-related occupations between 1930 and 1941. The risk of adenocarcinoma did not appear to decrease for at least 15 years after termination of exposure to wood dust. No cases of nasal adenocarcinoma were observed in men whose first exposure to wood dust occurred after 1941.

  20. Dramatic Outburst Reveals Nearest Black Hole

    Science.gov (United States)

    2000-01-01

    Scientists have discovered the closest black hole yet, a mere 1,600 light years from Earth. Its discovery was heralded by four of the most dramatic rapid X-ray intensity changes ever seen from one star. Astronomers from the Massachusetts Institute of Technology (MIT) and the National Science Foundation's National Radio Astronomy Observatory (NRAO) announced their findings at the American Astronomical Society's meeting in Atlanta. The black hole in the constellation Sagittarius, along with a normal star dubbed V4641 Sgr, form a violent system that briefly flooded part of our Milky Way Galaxy with X-rays and ejected subatomic particles moving at nearly the speed of light one day last September. At the peak of its X-ray output, V4641 Sgr was the brightest X-ray emitter in the sky. Astronomers call this type of system an X-ray nova because it suddenly becomes a bright source of X-rays, but this object shows characteristics never seen in an X-ray nova. "V4641 Sgr turns on and off so fast that it seems to represent a new subclass of X-ray novae," said Donald A. Smith, postdoctoral associate in MIT's Center for Space Research. Smith worked on data from this object with MIT principal research scientist Ronald Remillard and NRAO astronomer Robert Hjellming. "In X-rays, the intensity rose by a factor of more than 1,000 in seven hours, then dropped by a factor of 100 in two hours," Remillard said. The radio emission was seen as an image of an expanding "jet" of particles shooting out from the binary system. After reaching a maximum, the radio intensity dropped by a factor of nearly 40 within two days. "Radio telescopes give us a quick glimpse of something moving at a fantastically high velocity," Hjellming said. Black holes harbor enormous gravitational force that can literally rip the gas away from a nearby star. This transfer of gas is visible in many forms of radiation. Both orbiting X-ray telescopes and ground-based radio and optical telescopes saw the outburst of V4641

  1. Black holes with halos

    Science.gov (United States)

    Monten, Ruben; Toldo, Chiara

    2018-02-01

    We present new AdS4 black hole solutions in N =2 gauged supergravity coupled to vector and hypermultiplets. We focus on a particular consistent truncation of M-theory on the homogeneous Sasaki–Einstein seven-manifold M 111, characterized by the presence of one Betti vector multiplet. We numerically construct static and spherically symmetric black holes with electric and magnetic charges, corresponding to M2 and M5 branes wrapping non-contractible cycles of the internal manifold. The novel feature characterizing these nonzero temperature configurations is the presence of a massive vector field halo. Moreover, we verify the first law of black hole mechanics and we study the thermodynamics in the canonical ensemble. We analyze the behavior of the massive vector field condensate across the small-large black hole phase transition and we interpret the process in the dual field theory.

  2. Introducing the Black Hole

    Science.gov (United States)

    Ruffini, Remo; Wheeler, John A.

    1971-01-01

    discusses the cosmology theory of a black hole, a region where an object loses its identity, but mass, charge, and momentum are conserved. Include are three possible formation processes, theorized properties, and three way they might eventually be detected. (DS)

  3. Colliding black hole solution

    International Nuclear Information System (INIS)

    Ahmed, Mainuddin

    2005-01-01

    A new solution of Einstein equation in general relativity is found. This solution solves an outstanding problem of thermodynamics and black hole physics. Also this work appears to conclude the interpretation of NUT spacetime. (author)

  4. Black-hole thermodynamics

    International Nuclear Information System (INIS)

    Bekenstein, J.D.

    1980-01-01

    Including black holes in the scheme of thermodynamics has disclosed a deep-seated connection between gravitation, heat and the quantum that may lead us to a synthesis of the corresponding branches of physics

  5. Evaluation of challenges of wood imports to Iran using Fuzzy Delphi Analytical Hierarchy Process

    Directory of Open Access Journals (Sweden)

    amin arian

    2017-08-01

    Full Text Available Abstract:Considering the increasing consumption of wood and wood products in Iran and limited domestic sources of wood and shortage of wood raw material in Iran, wood raw material imports is a solution for Iranian developing wood industries' wood procurement.But, wood imports to Iran, always faced with a lot of challenges. The aim of this research is to determine and evaluate the challenges in the way of wood imports to Iran. The research method used in this study is a descriptive-analytic method. The analytic method used in the study to evaluate the challenges is the Fuzzy Delphi Analytical Hierarchy Process (FDAHP. First the findings of previous researches in the field and the literature were studied and doing interviews with industry experts, the challenges in the way of wood imports to Iran were extracted and classified in 5 groups and 35 factors and were evaluated.The results shows that in the first level (groups the regulation, economic, politic, infrastructure and management groups have the most importance respectively. In second level (challenges, plant protection regulations have the most importance. After that, exchange rate tolerance, oil income, banking support and GDP have most importance respectively.

  6. Wood biomass: The potential of willow

    International Nuclear Information System (INIS)

    White, E.H.; Abrahamson, L.P.

    1991-10-01

    Experiments were established in central New York State in spring, 1987, to evaluate the potential of Salix for wood biomass production using ultrashort-rotation intensive-culture techniques. Five selected willow clones and one hybrid poplar clone planted at 1 x 1 foot spacing were tested for biomass production with annual coppicing. This report presents results of this research as of December 31, 1990. (VC)

  7. Transmission Electron Microscopy for Wood and Fiber Analysis − A Review

    Directory of Open Access Journals (Sweden)

    Mehedi Reza

    2015-07-01

    Full Text Available This review describes use of transmission electron microscopy (TEM in wood and fiber analysis. Analytical techniques and sample preparation methods are used to localize substructures of the cell wall polymers and are discussed in this review. The ultrastructural features of the wood cell walls, the structures formed by microfibrils, and the distribution of cell wall polymers, as revealed by TEM, are covered. Research investigating the distribution of lignin in tension and compression woods using TEM is reviewed. Different kinds of wood biodegrading enzymes localized using TEM are mentioned. Additional features of TEM, i.e., 3D imaging, analytical TEM, and electron diffraction are discussed. Lastly, a comparison between TEM and other imaging techniques used for wood and fiber research are made. Thus, this review provides insight into the contribution of TEM in wood research since its invention and demonstrates how to use it more effectively in the future.

  8. White dwarfs - black holes

    International Nuclear Information System (INIS)

    Sexl, R.; Sexl, H.

    1975-01-01

    The physical arguments and problems of relativistic astrophysics are presented in a correct way, but without any higher mathematics. The book is addressed to teachers, experimental physicists, and others with a basic knowledge covering an introductory lecture in physics. The issues dealt with are: fundamentals of general relativity, classical tests of general relativity, curved space-time, stars and planets, pulsars, gravitational collapse and black holes, the search for black holes, gravitational waves, cosmology, cosmogony, and the early universe. (BJ/AK) [de

  9. Magnonic black holes

    OpenAIRE

    Roldán-Molina, A.; Nunez, A.S.; Duine, R. A.

    2017-01-01

    We show that the interaction between spin-polarized current and magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons - the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the imp...

  10. Supersymmetric black holes

    OpenAIRE

    de Wit, Bernard

    2005-01-01

    The effective action of $N=2$, $d=4$ supergravity is shown to acquire no quantum corrections in background metrics admitting super-covariantly constant spinors. In particular, these metrics include the Robinson-Bertotti metric (product of two 2-dimensional spaces of constant curvature) with all 8 supersymmetries unbroken. Another example is a set of arbitrary number of extreme Reissner-Nordstr\\"om black holes. These black holes break 4 of 8 supersymmetries, leaving the other 4 unbroken. We ha...

  11. Black Holes and Thermodynamics

    OpenAIRE

    Wald, Robert M.

    1997-01-01

    We review the remarkable relationship between the laws of black hole mechanics and the ordinary laws of thermodynamics. It is emphasized that - in analogy with the laws of thermodynamics - the validity the laws of black hole mechanics does not appear to depend upon the details of the underlying dynamical theory (i.e., upon the particular field equations of general relativity). It also is emphasized that a number of unresolved issues arise in ``ordinary thermodynamics'' in the context of gener...

  12. Aquatic wood -- an insect perspective

    Science.gov (United States)

    Peter S. Cranston; Brendan McKie

    2006-01-01

    Immersed wood provides refugia and substrate for a diverse array of macroinvertebrates, and food for a more restricted genuinely xylophagous fauna. Worldwide, xylophages are found across aquatic insect orders, including Coleoptera, Diptera, Trichoptera and Plecoptera. Xylophages often are specialised, feeding on the wood surface or mining deep within. Many feed...

  13. 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

  14. Assessing potential sustainable wood yield

    Science.gov (United States)

    Robert F. Powers

    2001-01-01

    Society is making unprecedented demands on world forests to produce and sustain many values. Chief among them is wood supply, and concerns are rising globally about the ability of forests to meet increasing needs. Assessing this is not easy. It requires a basic understanding of the principles governing forest productivity: how wood yield varies with tree and stand...

  15. 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...

  16. 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

  17. Holistic approach to wood protection

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

    When untreated wood is exposed to adverse outdoor conditions, nature has a series of chemistries to degrade it to its original building blocks of carbon dioxide and water. Fungi, termites, heat, moisture, ultraviolet (UV) energy, and chemicals take their toll on the performance properties of wood. We tend to study each of these degradation chemistries as individual...

  18. 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...

  19. 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...

  20. 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.

  1. Impact of chromated copper arsenate (CCA) in wood mulch.

    Science.gov (United States)

    Townsend, Timothy G; Solo-Gabriele, Helena; Tolaymat, Thabet; Stook, Kristin

    2003-06-20

    The production of landscape mulch is a major market for the recycling of yard trash and waste wood. When wood recovered from construction and demolition (C&D) debris is used as mulch, it sometimes contains chromated copper arsenate (CCA)-treated wood. The presence of CCA-treated wood may cause some potential environmental problems as a result of the chromium, copper, and arsenic present. Research was performed to examine the leachability of the three metals from a variety of processed wood mixtures in Florida. The mixtures tested included mixed wood from C&D debris recycling facilities and mulch purchased from retail outlets. The synthetic precipitation leaching procedure (SPLP) was performed to examine the leaching of chromium, copper and arsenic. Results were compared to Florida's groundwater cleanup target levels (GWCTLs). Eighteen of the 22 samples collected from C&D debris processing facilities leached arsenic at concentrations greater than Florida's GWCTL of 50 microg/l. The mean leachable arsenic concentration for the C&D debris samples was 153 microg/l with a maximum of 558 microg/l. One of the colored mulch samples purchased from a retail outlet leached arsenic above 50 microg/l, while purchased mulch samples derived from virgin materials did not leach detectable arsenic (<5 microg/l). A mass balance approach was used to compute the potential metal concentrations (mg/kg) that would result from CCA-treated wood being present in wood mulch. Less than 0.1% CCA-treated wood would cause a mulch to exceed Florida's residential clean soil guideline for arsenic (0.8 mg/kg).

  2. BEHAVIOR OF GLUED JOINTS OF EUCALYPTUS sp. SAWN WOOD

    Directory of Open Access Journals (Sweden)

    Octávio Barbosa Plaster

    2008-09-01

    Full Text Available This research evaluated eucalypt wood adhesion capacity. The material evaluated was a commercial sawn wood composed by a blend of species of the genus Eucalyptus. The adhesives used were resorcinol-formaldehyde and polyvinila acetate (PVAc. The wood was segregated in three density with 0% of moisture content: class 1; 2 and 3 that, when combined (class1 x class1; 2x2; 3x3; 1x2; 1x3; 2x3 resulted in six treatments. The performance of the adhesion was evaluated by the shear strength to parallel compression and by wood failure in the glue line. The obtained results allowed to conclude that the adhesion of the combinations of wood/adhesive presented satisfactory performance. The average shear strength of the joints were shown equivalent to the shear strength of the solid wood with similar performance of adhesion in the two adhesives. In general, resorcinol-formaldheyde adhesive presented higher values (74.41% for wood failure in the joints, but similar to all treatments. The adhesion of samples of higher density presented lower performance probably when only the values of wood failure are considered. The values for the strength of glued joints, in general, were similar when analyzed the results achieved with the resorcinol-formaldehyde adhesive- base 140,56 Kgf/cm2. To polyvinila acetate the values of wood failure decrease when the density increase (65.94%, but the resistance in the glue line was positively affected (140.25 Kgf/cm2. In general, the density influenced the adhesion of the joints for the employed adhesives.

  3. Report on achievements in fiscal 1998. Demonstrative research of an alkali recovery process in the non-wood pulp paper manufacturing industry; 1998 nendo himokuzai pulp seishi sangyo arukari kaishu process ni kakawaru jissho kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-01

    This project is intended of performing demonstrative research jointly with China on a system to efficiently extract, condense, and combust black liquor in a non-wood pulp paper manufacturing plant in China to recover alkaline solution and heat energy, and to contribute to proliferation of the system. Specifically, an alkali recovery plant is built in Cangshan Paper Making Plant in Shandong Province to verify conservation in energy and reduction environmental load. This fiscal year has performed (1) component researches and related technology investigations, and (2) device design and fabrication. For Item 1, the extractor adopted the spiral net type, and the condensation device adopted the falling film evaporator of full-can plate type. For the silica removing agent, data were acquired on reduction of silica in the black liquor and effect of reducing the black liquor viscosity. Basic design requirements were established for an alkali recovery process for a pulp production plant of 75 t/d. Regarding Item 2, prepared were the material and heat balance tables for the black liquor extractor and the black liquor condenser, process flow diagrams (PFD), device specifications, a meter list, and a summary utility consumption list, and confirmed them with the Chinese side. For the black liquor combustion device and the caustification device, PFD and device list prepared by the Chinese side were acquired to start the basic design. (NEDO)

  4. The Swedish wood fuel market

    International Nuclear Information System (INIS)

    Hillring, Bengt

    1999-01-01

    In Sweden, wood fuels are traditionally used in the Swedish forest products industry and for heating of single-family houses. More recently they are also become established as an energy source for district heating and electricity production. Energy policy, especially the energy taxation system, has favoured wood fuels and other biofuels, mainly for environmental reasons. There is now an established commercial market for wood fuels in the district heating sector, which amounts to 45 PJ and is growing 20 per cent annually. Price levels have been stable in current prices for a decade, mainly because of good access to wood fuels. Price levels are dominated by production costs on a market that is largely governed by the buyer. It is expected that the use of wood fuels will increased in Sweden in the future, which will push a further development of this section on the market and bring about technological changes in the area. (Author)

  5. 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...

  6. Changes in structural and chemical components of wood delignified by fungi

    Energy Technology Data Exchange (ETDEWEB)

    Blanchette, R.A.; Otjen, L.; Effland, M.J.; Eslyn, W.E.

    1985-01-01

    Cerrena unicolor, Ganoderma applanatum, Ischnoderma resinosum and Poria medulla-panis were associated with birch (Betula papyrifera) wood that had been selectively delignified in the forest. Preferential lignin degradation was not uniformly distributed throughout the decayed wood. A typical white rot causing a simultaneous removal of all cell wall components was also present. In the delignified wood, 95 to 98% of the lignin was removed as well as substantial amounts of hemicelluloses. Scanning and transmission electron microscopy were used to identify the micromorphological and ultrastructural changes that occurred in the cells during degradation. In delignified areas the compound middle lamella was extensively degraded causing a defibration of cells. The secondary wall, especially the S2 layer, remained relatively unaltered. In simultaneously white-rotted wood all cell wall layers were progressively removed from the lumen toward the middle lamella causing erosion troughs or holes to form. Large voids filled with fungal mycelia resulted from a coalition of degraded areas. Birch wood decayed in laboratory soil-block tests was also intermittently delignified, selective delignification, sparsely distributed throughout the wood, and a simultaneous rot resulting in the removal of all cell wall components were evident. SEM appears to be an appropriate technique for examining selectively delignified decayed wood. 30 references.

  7. Short rotation Wood Crops Program

    Energy Technology Data Exchange (ETDEWEB)

    Wright, L.L.; Ehrenshaft, A.R.

    1990-08-01

    This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program for the year ending September 30, 1989. The primary goal of this research program, sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division, is the development of a viable technology for producing renewable feedstocks for conversion to biofuels. One of the more significant accomplishments was the documentation that short-rotation woody crops total delivered costs could be $40/Mg or less under optimistic but attainable conditions. By taking advantage of federal subsidies such as those offered under the Conservation Reserve Program, wood energy feedstock costs could be lower. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. 8 figs., 20 tabs.

  8. Supporting the development process for building products by the use of research portfolio analysis: A case study for wood plastics composite materials

    Directory of Open Access Journals (Sweden)

    Daniel Friedrich

    2016-06-01

    Our study evaluated European scientific projects in composites from which we derived a Research Portfolio serving as future matrix for ideation. It was found that research databanks can serve as basis for strategic innovation planning. We were able to identify several appropriate future technologies and material applications in the field of bio-based plastics composites. Our methodology particularly supports manufacturers with less formalized innovation processes.

  9. Supporting the development process for building products by the use of research portfolio analysis: A case study for wood plastics composite materials

    OpenAIRE

    Friedrich, Daniel; Luible, Andreas

    2016-01-01

    Today’s plastics are increasingly compounded using renewable fibres. Such composites raised the interest of the massively bulk-plastics consuming building industry. However, “green” products are still rare and their development constitutes a challenge particularly for small companies. Our study evaluated European scientific projects in composites from which we derived a Research Portfolio serving as future matrix for ideation. It was found that research databanks can serve as basis for str...

  10. 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).

  11. Mineral preservatives in the wood of Stradivari and Guarneri.

    Directory of Open Access Journals (Sweden)

    Joseph Nagyvary

    implications with regard to how the green tone wood should be treated, which chould lead to changes in the practice of violin-making. This research should inspire others to analyze more antique violins for their chemical contents.

  12. Logging potentials and energy wood resources in southern Finland; Potentiaaliset hakkuumahdollisuudet ja energiapuuvarat Etelae- Suomessa

    Energy Technology Data Exchange (ETDEWEB)

    Pesonen, M; Malinen, J [Finnish Forest Research Inst. METLA, Vantaa (Finland)

    1997-12-01

    Development of energy wood resources in Southern Finland over the next 40 years was studied on the basis of four cutting scenarios. Development of energy wood accrual was considered on the production cost levels of FIM 45/MWh and FIM 55/MWh in scenarios describing sustainable cutting potential, long-term cutting plans of forest owners and cutting of industrial mechandable wood over the years of depression. Effects of limitations concerning energy wood harvesting from meagre forest land and bogs on the energy wood accruals of sustainable cutting potential were also studied. The energy wood potential in Southern Finland was estimated at 3.6 million m{sup 3}/a on the production cost level of FIM 45/MWh. The energy wood accrual equal to sustainable cutting potential was 70 % of the energy wood potential. The energy wood potential increased to 8.8 m{sup 3}/a when the production cost level increased to FIM 55/MWh, the energy wood accrual of sustainable cutting potential being 51 %. The energy wood accruals according to felling plans of forest owners and cuttings over the years of depression were smaller than that of sustainable cutting potential, due to smaller loggings. Limitation of energy wood harvesting from meagre forest land and bogs would reduce the energy wood accrual of sustainable cutting potential by 22 %. This would involve a reduction of one million m{sup 3} in the harvesting potential. The energy wood accrual of sustainable cutting potential in Finland was 5.8 million m{sup 3}/a on the production cost level of FIM 55/MWh. This is equal to the aim set by the BIOENERGY Research Programme for the use potential of 1 Mtoe (equivalent oil tonne) on the production cost level of FIM 45/MWh

  13. Engineering Biodegradable Flame Retardant Wood-Plastic Composites

    Science.gov (United States)

    Zhang, Linxi

    Wood-plastic composites (WPCs), which are produced by blending wood and polymer materials, have attracted increasing attentions in market and industry due to the low cost and excellent performance. In this research, we have successfully engineered WPC by melt blending Polylactic Acid (PLA) and Poly(butylene adipate-co-terphthalate) (PBAT) with recycled wood flour. The thermal property and flammability of the composite are significantly improved by introducing flame retardant agent resorcinol bis(biphenyl phosphate) (RDP). The mechanical and morphological properties are also investigated via multiple techniques. The results show that wood material has increased toughness and impact resistance of the PLA/PBAT polymer matrix. SEM images have confirmed that PLA and PBAT are immiscible, but the incompatibility is reduced by the addition of wood. RDP is initially dispersed in the blends evenly. It migrates to the surface of the sample after flame application, and serves as a barrier between the fire and underlying polymers and wood mixture. It is well proved in the research that RDP is an efficient flame retardant agent in the WPC system.

  14. Economic analysis of wood energy valorization

    International Nuclear Information System (INIS)

    Fries, Juliana.

    1988-01-01

    Companies linked to the lumber activities began to concern about the valorization of their industrial residues: either by creating new products or by utilizing them for energy generation. At the same time, companies from other sectors began investing in reforestations dedicated to energy generation (mainly eucalyptus), induced by the possibility of obtaining tax incentives and by the need of assuring their own provisions of wood, thus minimizing this raw-material, as well as its sensibility to the variation of its price in the market. However almost nothing have been researched, either about the economical feasibility of energetic valorization of the lumber in the form of industrial residues or as wood supplied by reforestation dedicated to energy generation. This dissertation propose to examine those cases analysing the concerned costs and their economical feasibility. (author). 20 refs., 19 figs., 32 tabs

  15. Research on the use of particles coming from almond husk as fillers for vinyl plastisols to manufacture hollow pieces with similar surface finishing than wood by using a rotational moulding process

    Science.gov (United States)

    Crespo Amoros, Jose Enrique

    PVC pastes or plasticized PVC offer great possibilities in the industrial field in which this research work has been developed since they show great relevance in plastic processing. On one hand, it is important to study these materials from different points of view: quality improvement, wide range of performance, high versatility, low costs,.... On the other hand, most of the industrial fields that usually employ these polymeric materials are characterized by developing products on which aesthetic considerations and surface finishing acquire special relevance. These industrial fields include all those on which new designs require complex shapes and new and novelty surface finishing such as interior design (furniture, wood products,...) toys industry, houseware, shoe industry,.... The main aim of this work is to improve the use of PVC plastisols in these industrial fields by optimizing formulations with new additives (low toxicity plasticizers) and fillers (lignocellulosic wastes) to obtain new materials that minimize damages to environment. In this work, we have developed new plastisol formulations based on the use of low toxicity plasticizers to obtain more ecological plastisols. We have used a biodegradable plasticizer DINCH which is a derivative of a dicarboxilate as substitute of traditional plasticizers based on phthalates. As we are working with relatively new plasticizers (specially at industrial level) we have performed a whole study of its properties by using different experimental analysis techniques such as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamical-mechanical analysis (DMA) and espectrofotometric techniques (visible and infrared). Furthermore a complete mechanical characterization has been carried out to analyze the most important parameters that influence on materials properties such as processing parameters (temperature and time) and plastisol formulations (mainly plasticizer content). We have also performed a

  16. URBAN WOOD/COAL CO-FIRING IN THE NIOSH BOILER PLANT

    Energy Technology Data Exchange (ETDEWEB)

    James T. Cobb Jr.

    2005-02-10

    gasification project at its site. Throughout much of this total project the Principal Investigator has counseled two small businesses in developing a waxed cardboard pellet business. A recent test burn of this biofuel appears successful and a purchase contract is anticipated soon. During the past two months a major tree-trimming firm has shown an active interest in entering the wood-chip fuel market in the Pittsburgh area and has contacted the NBP, among others, as potential customers. The NBP superintendent is currently in discussion with the facilities management of the Bruceton Research Center about resuming their interest in cofiring this renewable fuel to the stoker there.

  17. Before Inflation and after Black Holes

    Science.gov (United States)

    Stoltenberg, Henry

    This dissertation covers work from three research projects relating to the physics before the start of inflation and information after the decay of a black hole. For the first project, we analyze the cosmological role of terminal vacua in the string theory landscape, and point out that existing work on this topic makes very strong assumptions about the properties of the terminal vacua. We explore the implications of relaxing these assumptions (by including "arrival" as well as "departure" terminals) and demonstrate that the results in earlier work are highly sensitive to their assumption of no arrival terminals. We use our discussion to make some general points about tuning and initial conditions in cosmology. The second project is a discussion of the black hole information problem. Under certain conditions the black hole information puzzle and the (related) arguments that firewalls are a typical feature of black holes can break down. We first review the arguments of Almheiri, Marolf, Polchinski and Sully (AMPS) favoring firewalls, focusing on entanglements in a simple toy model for a black hole and the Hawking radiation. By introducing a large and inaccessible system entangled with the black hole (representing perhaps a de Sitter stretched horizon or inaccessible part of a landscape) we show complementarity can be restored and firewalls can be avoided throughout the black hole's evolution. Under these conditions black holes do not have an "information problem". We point out flaws in some of our earlier arguments that such entanglement might be generically present in some cosmological scenarios, and call out certain ways our picture may still be realized. The third project also examines the firewall argument. A fundamental limitation on the behavior of quantum entanglement known as "monogamy" plays a key role in the AMPS argument. Our goal is to study and apply many-body entanglement theory to consider the entanglement among different parts of Hawking radiation and

  18. Wood product industry - present state and studies of the development alternatives; Puuteollisuuden nykytilan ja haasteiden arviointia

    Energy Technology Data Exchange (ETDEWEB)

    Holmijoki, O.; Paajanen, T.; Kairi, M.

    2007-07-01

    In this research project the development of the wood products industry and its operating environment in Finland was studied using statistical data mainly from years 1995 - 2003. In this context, the wood products industry includes the sawmilling industry, the plywood and other wood panel industry, prefabricated wooden housing and the building joinery industry, wood packing manufacture and the manufacture of other wooden products. The development of the wood products industry and its operating environment has been estimated by combining statistical data about the business economy, production economy and the national economy from the Central Statistical Office of Finland together with data from the Finnish Forest Research Institute. Based on statistical data, the wood product markets, profitability and cost structure of branches, input market, use of labour force and investments have been studied. The economic importance of the wood products industry has been estimated at a national and a local level. Challenges facing wood products industry branches have been analysed using example calculations based on input-output theory. In the evaluation method, the business environment of the wood products industry branches and related branches, have been described with a use table at basic prices commonly using in the national economy. This method has enabled the direct and indirect effects of simultaneous quantity and price changes occurring in the wood product markets and markets related to the wood product industry, to be analysed. In the example calculations, variation of sawn timber production and log import, as well as the increments of sawn timber upgrading, wood product usage in building, wood panel production and purchase energy price, were reviewed

  19. σ-holes and π-holes: Similarities and differences.

    Science.gov (United States)

    Politzer, Peter; Murray, Jane S

    2018-04-05

    σ-Holes and π-holes are regions of molecules with electronic densities lower than their surroundings. There are often positive electrostatic potentials associated with them. Through these potentials, the molecule can interact attractively with negative sites, such as lone pairs, π electrons, and anions. Such noncovalent interactions, "σ-hole bonding" and "π-hole bonding," are increasingly recognized as being important in a number of different areas. In this article, we discuss and compare the natures and characteristics of σ-holes and π-holes, and factors that influence the strengths and locations of the resulting electrostatic potentials. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. 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.

  1. Wood fuels sources and markets

    International Nuclear Information System (INIS)

    Koopmans, Auke

    2003-01-01

    Biomass energy is an important source of energy in most Asian countries. Households and industries use substantial amounts of fuel wood, charcoal and other biomass energy, such as agricultural residues, dung, leaves and sawmill residues. The main household applications are cooking and heating whereas industrial applications range widely. This paper provides an overview of estimates on the production and trade of biomass fuels in the South-east Asia region. The flows and channels used in the supply of wood fuels in different countries were analysed. This paper may help in identifying policy gaps with regards to the supply and consumption of wood fuels from both forest and non-forest sources. (Author)

  2. Chandra Data Reveal Rapidly Whirling Black Holes

    Science.gov (United States)

    2008-01-01

    A new study using results from NASA's Chandra X-ray Observatory provides one of the best pieces of evidence yet that many supermassive black holes are spinning extremely rapidly. The whirling of these giant black holes drives powerful jets that pump huge amounts of energy into their environment and affects galaxy growth. A team of scientists compared leading theories of jets produced by rotating supermassive black holes with Chandra data. A sampling of nine giant galaxies that exhibit large disturbances in their gaseous atmospheres showed that the central black holes in these galaxies must be spinning at near their maximum rates. People Who Read This Also Read... NASA’s Swift Satellite Catches First Supernova in The Act of Exploding Black Holes Have Simple Feeding Habits Jet Power and Black Hole Assortment Revealed in New Chandra Image Erratic Black Hole Regulates Itself "We think these monster black holes are spinning close to the limit set by Einstein's theory of relativity, which means that they can drag material around them at close to the speed of light," said Rodrigo Nemmen, a visiting graduate student at Penn State University, and lead author of a paper on the new results presented at American Astronomical Society in Austin, Texas. The research reinforces other, less direct methods previously used which have indicated that some stellar and supermassive black holes are spinning rapidly. According to Einstein's theory, a rapidly spinning black hole makes space itself rotate. This effect, coupled with gas spiraling toward the black hole, can produce a rotating, tightly wound vertical tower of magnetic field that flings a large fraction of the inflowing gas away from the vicinity of the black hole in an energetic, high-speed jet. Computer simulations by other authors have suggested that black holes may acquire their rapid spins when galaxies merge, and through the accretion of gas from their surroundings. "Extremely fast spin might be very common for large

  3. 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....

  4. 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...

  5. 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...

  6. 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…

  7. 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...

  8. 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

  9. Merging Black Holes

    Science.gov (United States)

    Centrella, Joan

    2012-01-01

    The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as future. space-based detectors. Since the merger takes place in the regime of strong dynamical gravity, computing the resulting gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. For many years, numerical codes designed to simulate black hole mergers were plagued by a host of instabilities. However, recent breakthroughs have conquered these instabilities and opened up this field dramatically. This talk will focus on.the resulting 'gold rush' of new results that is revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics

  10. Black-hole astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Bender, P. [Univ. of Colorado, Boulder, CO (United States); Bloom, E. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Cominsky, L. [Sonoma State Univ., Rohnert Park, CA (United States). Dept. of Physics and Astronomy] [and others

    1995-07-01

    Black-hole astrophysics is not just the investigation of yet another, even if extremely remarkable type of celestial body, but a test of the correctness of the understanding of the very properties of space and time in very strong gravitational fields. Physicists` excitement at this new prospect for testing theories of fundamental processes is matched by that of astronomers at the possibility to discover and study a new and dramatically different kind of astronomical object. Here the authors review the currently known ways that black holes can be identified by their effects on their neighborhood--since, of course, the hole itself does not yield any direct evidence of its existence or information about its properties. The two most important empirical considerations are determination of masses, or lower limits thereof, of unseen companions in binary star systems, and measurement of luminosity fluctuations on very short time scales.

  11. Turbulent black holes.

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-27

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability-which is triggered above a certain perturbation amplitude threshold-akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies-a phenomenon reminiscent of the inverse cascade displayed by (2+1)-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids.

  12. Anyon black holes

    Science.gov (United States)

    Aghaei Abchouyeh, Maryam; Mirza, Behrouz; Karimi Takrami, Moein; Younesizadeh, Younes

    2018-05-01

    We propose a correspondence between an Anyon Van der Waals fluid and a (2 + 1) dimensional AdS black hole. Anyons are particles with intermediate statistics that interpolates between a Fermi-Dirac statistics and a Bose-Einstein one. A parameter α (0 quasi Fermi-Dirac statistics for α >αc, but a quasi Bose-Einstein statistics for α quasi Bose-Einstein statistics. For α >αc and a range of values of the cosmological constant, there is, however, no event horizon so there is no black hole solution. Thus, for these values of cosmological constants, the AdS Anyon Van der Waals black holes have only quasi Bose-Einstein statistics.

  13. Black holes go supersonic

    Energy Technology Data Exchange (ETDEWEB)

    Leonhardt, Ulf [School of Physics and Astronomy, University of St. Andrews (United Kingdom)

    2001-02-01

    In modern physics, the unification of gravity and quantum mechanics remains a mystery. Gravity rules the macroscopic world of planets, stars and galaxies, while quantum mechanics governs the micro-cosmos of atoms, light quanta and elementary particles. However, cosmologists believe that these two disparate worlds may meet at the edges of black holes. Now Luis Garay, James Anglin, Ignacio Cirac and Peter Zoller at the University of Innsbruck in Austria have proposed a realistic way to make an artificial 'sonic' black hole in a tabletop experiment (L J Garay et al. 2000 Phys. Rev. Lett. 85 4643). In the February issue of Physics World, Ulf Leonhardt of the School of Physics and Astronomy, University of St. Andrews, UK, explains how the simulated black holes work. (U.K.)

  14. Black Hole Paradoxes

    International Nuclear Information System (INIS)

    Joshi, Pankaj S.; Narayan, Ramesh

    2016-01-01

    We propose here that the well-known black hole paradoxes such as the information loss and teleological nature of the event horizon are restricted to a particular idealized case, which is the homogeneous dust collapse model. In this case, the event horizon, which defines the boundary of the black hole, forms initially, and the singularity in the interior of the black hole at a later time. We show that, in contrast, gravitational collapse from physically more realistic initial conditions typically leads to the scenario in which the event horizon and space-time singularity form simultaneously. We point out that this apparently simple modification can mitigate the causality and teleological paradoxes, and also lends support to two recently suggested solutions to the information paradox, namely, the ‘firewall’ and ‘classical chaos’ proposals. (paper)

  15. Bringing Black Holes Home

    Science.gov (United States)

    Furmann, John M.

    2003-03-01

    Black holes are difficult to study because they emit no light. To overcome this obstacle, scientists are trying to recreate a black hole in the laboratory. The article gives an overview of the theories of Einstein and Hawking as they pertain to the construction of the Large Hadron Collider (LHC) near Geneva, Switzerland, scheduled for completion in 2006. The LHC will create two beams of protons traveling in opposing directions that will collide and create a plethora of scattered elementary particles. Protons traveling in opposite directions at very high velocities may create particles that come close enough to each other to feel their compacted higher dimensions and create a mega force of gravity that can create tiny laboratory-sized black holes for fractions of a second. The experiments carried out with LHC will be used to test modern string theory and relativity.

  16. Slowly balding black holes

    International Nuclear Information System (INIS)

    Lyutikov, Maxim; McKinney, Jonathan C.

    2011-01-01

    The 'no-hair' theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively ''frozen in'' the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes N B =eΦ ∞ /(πc(ℎ/2π)), where Φ ∞ ≅2π 2 B NS R NS 3 /(P NS c) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole's magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

  17. Waste wood as bioenergy feedstock. Climate change impacts and related emission uncertainties from waste wood based energy systems in the UK.

    Science.gov (United States)

    Röder, Mirjam; Thornley, Patricia

    2018-04-01

    Considering the urgent need to shift to low carbon energy carriers, waste wood resources could provide an alternative energy feedstock and at the same time reduce emissions from landfill. This research examines the climate change impacts and related emission uncertainties of waste wood based energy. For this, different grades of waste wood and energy application have been investigated using lifecycle assessment. Sensitivity analysis has then been applied for supply chain processes and feedstock properties for the main emission contributing categories: transport, processing, pelletizing, urea resin fraction and related N 2 O formation. The results show, depending on the waste wood grade, the conversion option, scale and the related reference case, that emission reductions of up to 91% are possible for non-treated wood waste. Compared to this, energy from treated wood waste with low contamination can achieve up to 83% emission savings, similar to untreated waste wood pellets, but in some cases emissions from waste wood based energy can exceed the ones of the fossil fuel reference - in the worst case by 126%. Emission reductions from highly contaminated feedstocks are largest when replacing electricity from large-scale coal and landfill. The highest emission uncertainties are related to the wood's resin fraction and N 2 O formation during combustion and, pelletizing. Comparing wood processing with diesel and electricity powered equipment also generated high variations in the results, while emission variations related to transport are relatively small. Using treated waste wood as a bioenergy feedstock can be a valid option to reduce emissions from energy production but this is only realisable if coal and landfill gas are replaced. To achieve meaningful emission reduction in line with national and international climate change targets, pre-treatment of waste wood would be required to reduce components that form N 2 O during the energy conversion. Copyright © 2017

  18. Application of a CCA-treated wood waste decontamination process to other copper-based preservative-treated wood after disposal

    Energy Technology Data Exchange (ETDEWEB)

    Janin, Amelie, E-mail: amelie.janin@ete.inrs.ca [University of Toronto, Faculty of Forestry, 33, Willcocks St., Toronto, ON, M5S 3B3 (Canada); Coudert, Lucie, E-mail: lucie.coudert@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Riche, Pauline, E-mail: pauline.riche@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Mercier, Guy, E-mail: guy_mercier@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Cooper, Paul, E-mail: p.cooper@utoronto.ca [University of Toronto, Faculty of Forestry, 33, Willcocks St., Toronto, ON, M5S 3B3 (Canada); Blais, Jean-Francois, E-mail: blaisjf@ete.inrs.ca [Institut national de la recherche scientifique (Centre Eau, Terre et Environnement), Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada)

    2011-02-28

    Research highlights: {yields} This paper describes a process for the metal removal from treated (CA-, ACQ- or MCQ-) wood wastes. {yields} This sulfuric acid leaching process is simple and economic. {yields} The remediated wood could be recycled in the industry. - Abstract: Chromated copper arsenate (CCA)-treated wood was widely used until 2004 for residential and industrial applications. Since 2004, CCA was replaced by alternative copper preservatives such as alkaline copper quaternary (ACQ), copper azole (CA) and micronized copper quaternary (MCQ), for residential applications due to health concerns. Treated wood waste disposal is becoming an issue. Previous studies identified a chemical process for decontaminating CCA-treated wood waste based on sulfuric acid leaching. The potential application of this process to wood treated with the copper-based preservatives (alkaline copper quaternary (ACQ), copper azole (CA) and micronized copper quaternary (MCQ)) is investigated here. Three consecutive leaching steps with 0.1 M sulfuric acid at 75 deg, C for 2 h were successful for all the types of treated wood and achieved more than 98% copper solubilisation. The different acidic leachates produced were successively treated by coagulation using ferric chloride and precipitation (pH = 7) using sodium hydroxide. Between 94 and 99% of copper in leachates could be recovered by electrodeposition after 90 min using 2 A electrical current. Thus, the process previously developed for CCA-treated wood waste decontamination could be efficiently applied for CA-, ACQ- or MCQ-treated wood.

  19. Integrated production of merchantable wood and wood fuels in industry; Teollisuuden ainespuun ja puupolttoaineen integroitu tuotanto

    Energy Technology Data Exchange (ETDEWEB)

    Kuvaja, K [Enso Oy, Imatra (Finland). Forest Dept.

    1997-12-01

    The aim of this project is the economically profitable integrated harvesting of industrial wood and firewood especially in harvesting of small-diameter first thinning wood. The research in 1994 was concentrated on improvement of the quality of the chipping methods based on chain-flail debarking chipping method, and on determination of the possible utilisation targets for the fuel fraction. A reasonably large drum debarking test was also carried out at the industrial scale debarking station of the Enocell Oy. More than 80 000 m{sup 3} of first thinning wood was delivered by Enocell during this project. The quality of wood chips, produced using the chain-flail delimbing method, could be improved in the case of pine nearly to the required quality level, but additional measures are still needed in the case of birch. The fuel fraction deliveries to different points of utilisation was started. The particle size of the fuel fraction appeared to be good after crushing. In 1995 a chain-flail-drum debarking chipping unit was developed to improve and homogenise the quality of chips. (orig.)

  20. Modeling black hole evaporation

    CERN Document Server

    Fabbri, Alessandro

    2005-01-01

    The scope of this book is two-fold: the first part gives a fully detailed and pedagogical presentation of the Hawking effect and its physical implications, and the second discusses the backreaction problem, especially in connection with exactly solvable semiclassical models that describe analytically the black hole evaporation process. The book aims to establish a link between the general relativistic viewpoint on black hole evaporation and the new CFT-type approaches to the subject. The detailed discussion on backreaction effects is also extremely valuable.

  1. Characterizing Black Hole Mergers

    Science.gov (United States)

    Baker, John; Boggs, William Darian; Kelly, Bernard

    2010-01-01

    Binary black hole mergers are a promising source of gravitational waves for interferometric gravitational wave detectors. Recent advances in numerical relativity have revealed the predictions of General Relativity for the strong burst of radiation generated in the final moments of binary coalescence. We explore features in the merger radiation which characterize the final moments of merger and ringdown. Interpreting the waveforms in terms of an rotating implicit radiation source allows a unified phenomenological description of the system from inspiral through ringdown. Common features in the waveforms allow quantitative description of the merger signal which may provide insights for observations large-mass black hole binaries.

  2. Moulting Black Holes

    OpenAIRE

    Bena, Iosif; Chowdhury, Borun D.; de Boer, Jan; El-Showk, Sheer; Shigemori, Masaki

    2011-01-01

    We find a family of novel supersymmetric phases of the D1-D5 CFT, which in certain ranges of charges have more entropy than all known ensembles. We also find bulk BPS configurations that exist in the same range of parameters as these phases, and have more entropy than a BMPV black hole; they can be thought of as coming from a BMPV black hole shedding a "hair" condensate outside of the horizon. The entropy of the bulk configurations is smaller than that of the CFT phases, which indicates that ...

  3. Are black holes springlike?

    Science.gov (United States)

    Good, Michael R. R.; Ong, Yen Chin

    2015-02-01

    A (3 +1 )-dimensional asymptotically flat Kerr black hole angular speed Ω+ can be used to define an effective spring constant, k =m Ω+2. Its maximum value is the Schwarzschild surface gravity, k =κ , which rapidly weakens as the black hole spins down and the temperature increases. The Hawking temperature is expressed in terms of the spring constant: 2 π T =κ -k . Hooke's law, in the extremal limit, provides the force F =1 /4 , which is consistent with the conjecture of maximum force in general relativity.

  4. Dancing with Black Holes

    Science.gov (United States)

    Aarseth, S. J.

    2008-05-01

    We describe efforts over the last six years to implement regularization methods suitable for studying one or more interacting black holes by direct N-body simulations. Three different methods have been adapted to large-N systems: (i) Time-Transformed Leapfrog, (ii) Wheel-Spoke, and (iii) Algorithmic Regularization. These methods have been tried out with some success on GRAPE-type computers. Special emphasis has also been devoted to including post-Newtonian terms, with application to moderately massive black holes in stellar clusters. Some examples of simulations leading to coalescence by gravitational radiation will be presented to illustrate the practical usefulness of such methods.

  5. Scattering from black holes

    International Nuclear Information System (INIS)

    Futterman, J.A.H.; Handler, F.A.; Matzner, R.A.

    1987-01-01

    This book provides a comprehensive treatment of the propagation of waves in the presence of black holes. While emphasizing intuitive physical thinking in their treatment of the techniques of analysis of scattering, the authors also include chapters on the rigorous mathematical development of the subject. Introducing the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical (Schwarzschild) black hole, the book then develops the formalism of spin weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic, and gravitational scattering. Details and results of numerical computations are given. The techniques involved have important applications (references are given) in acoustical and radar imaging

  6. Virtual Black Holes

    OpenAIRE

    Hawking, Stephen W.

    1995-01-01

    One would expect spacetime to have a foam-like structure on the Planck scale with a very high topology. If spacetime is simply connected (which is assumed in this paper), the non-trivial homology occurs in dimension two, and spacetime can be regarded as being essentially the topological sum of $S^2\\times S^2$ and $K3$ bubbles. Comparison with the instantons for pair creation of black holes shows that the $S^2\\times S^2$ bubbles can be interpreted as closed loops of virtual black holes. It is ...

  7. Superfluid Black Holes.

    Science.gov (United States)

    Hennigar, Robie A; Mann, Robert B; Tjoa, Erickson

    2017-01-13

    We present what we believe is the first example of a "λ-line" phase transition in black hole thermodynamics. This is a line of (continuous) second order phase transitions which in the case of liquid ^{4}He marks the onset of superfluidity. The phase transition occurs for a class of asymptotically anti-de Sitter hairy black holes in Lovelock gravity where a real scalar field is conformally coupled to gravity. We discuss the origin of this phase transition and outline the circumstances under which it (or generalizations of it) could occur.

  8. Magnonic Black Holes.

    Science.gov (United States)

    Roldán-Molina, A; Nunez, Alvaro S; Duine, R A

    2017-02-10

    We show that the interaction between the spin-polarized current and the magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons-the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the implications of magnonic horizons for spin-wave scattering and transport experiments, and for magnon entanglement.

  9. Partons and black holes

    International Nuclear Information System (INIS)

    Susskind, L.; Griffin, P.

    1994-01-01

    A light-front renormalization group analysis is applied to study matter which falls into massive black holes, and the related problem of matter with transplankian energies. One finds that the rate of matter spreading over the black hole's horizon unexpectedly saturates the causality bound. This is related to the transverse growth behavior of transplankian particles as their longitudinal momentum increases. This growth behavior suggests a natural mechanism to implement 't Hooft's scenario that the universe is an image of data stored on a 2 + 1 dimensional hologram-like projection

  10. Effect of Trichoderma-enriched organic charcoal in the integrated wood protection strategy.

    Directory of Open Access Journals (Sweden)

    Javier Ribera

    Full Text Available The gradual elimination of chromium from wood preservative formulations results in higher Cu leaching and increased susceptibility to wood decay fungi. Finding a sustainable strategy in wood protection has become of great interest among researchers. The objective of these in vitro studies was to demonstrate the effect of T-720-enriched organic charcoal (biochar against five wood decay basidiomycetes isolated from strongly damaged poles. For this purpose, the antagonistic potential of Trichoderma harzianum (strain T-720 was confirmed among other four Trichoderma spp. against five brown-rot basidiomycetes in dual culture tests. T-720 was genetically transformed and tagged with the green fluorescent protein (GFP in order to study its antagonistic mechanism against wood decay basidiomycetes. It was also demonstrated that T-720 inhibits the oxalic acid production by basidiomycetes, a well-known mechanism used by brown-rot fungi to detoxify Cu from impregnated wood. Additionally, this study evaluated the effect of biochar, alone or in combination with T-720, on Cu leaching by different preservatives, pH stabilization and prevention of wood decay caused by five basidiomycetes. Addition of biochar resulted in a significant Cu binding released from impregnated wood specimens. T-720-enriched biochar showed a significant reduction of wood decay caused by four basidiomycetes. The addition of T-720-enriched biochar to the soil into which utility poles are placed may improve the efficiency of Cr-free wood preservatives.

  11. Over spinning a black hole?

    Energy Technology Data Exchange (ETDEWEB)

    Bouhmadi-Lopez, Mariam; Cardoso, Vitor; Nerozzi, Andrea; Rocha, Jorge V, E-mail: mariam.bouhmadi@ist.utl.pt, E-mail: vitor.cardoso@ist.utl.pt, E-mail: andrea.nerozzi@ist.utl.pt, E-mail: jorge.v.rocha@ist.utl.pt [CENTRA, Department de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049 Lisboa (Portugal)

    2011-09-22

    A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this gedanken experiment for black holes in higher dimensions. We show that this particular way of destroying a black hole does not succeed and that Cosmic Censorship is preserved.

  12. Scalar fields in black hole spacetimes

    Science.gov (United States)

    Thuestad, Izak; Khanna, Gaurav; Price, Richard H.

    2017-07-01

    The time evolution of matter fields in black hole exterior spacetimes is a well-studied subject, spanning several decades of research. However, the behavior of fields in the black hole interior spacetime has only relatively recently begun receiving some attention from the research community. In this paper, we numerically study the late-time evolution of scalar fields in both Schwarzschild and Kerr spacetimes, including the black hole interior. We recover the expected late-time power-law "tails" on the exterior (null infinity, timelike infinity, and the horizon). In the interior region, we find an interesting oscillatory behavior that is characterized by the multipole index ℓ of the scalar field. In addition, we also study the extremal Kerr case and find strong indications of an instability developing at the horizon.

  13. Potential greenhouse gas benefits of transatlantic wood pellet trade

    International Nuclear Information System (INIS)

    Dwivedi, Puneet; Khanna, Madhu; Bailis, Robert; Ghilardi, Adrian

    2014-01-01

    Power utility companies in the United Kingdom are using imported wood pellets from the southern region of the United States for electricity generation to meet the legally binding mandate of sourcing 15% of the nation’s total energy consumption from renewable sources by 2020. This study ascertains relative savings in greenhouse gas (GHG) emissions for a unit of electricity generated using imported wood pellet in the United Kingdom under 930 different scenarios: three woody feedstocks (logging residues, pulpwood, and logging residues and pulpwood combined), two forest management choices (intensive and non-intensive), 31 plantation rotation ages (year 10 to year 40 in steps of 1 year), and five power plant capacities (20–100 MW in steps of 20 MW). Relative savings in GHG emissions with respect to a unit of electricity derived from fossil fuels in the United Kingdom range between 50% and 68% depending upon the capacity of power plant and rotation age. Relative savings in GHG emissions increase with higher power plant capacity. GHG emissions related to wood pellet production and transatlantic shipment of wood pellets typically contribute about 48% and 31% of total GHG emissions, respectively. Overall, use of imported wood pellets for electricity generation could help in reducing the United Kingdom’s GHG emissions. We suggest that future research be directed to evaluation of the impacts of additional forest management practices, changing climate, and soil carbon on the overall savings in GHG emissions related to transatlantic wood pellet trade. (paper)

  14. A Review of Wood Plastic Composites effect on the Environment

    Directory of Open Access Journals (Sweden)

    Ahmed Taifor Azeez

    2017-05-01

    Full Text Available Wood Plastic Composites (WPCs are environmentally friend materials with a wide range of applications in the field of constructions, comprising high mechanical and physical properties with low cost raw materials as plastic wastes and different carpentry process wood reminder. The effects of wood, plastic waste and additives on various properties of the material such as mechanical (modulus of elasticity and modulus of rupture, physical (moisture absorption and fire retardancy have been investigated in order to push the output functions of the products to the limits of work conditions requirements. This study, overviews the importance of Wood Plastic Composites in conserving the environment by depletion post consume plastics from landfills, and the impact of these composites in developing the economic via opening new flourished markets for modern products. Both the ecological and economical requirements oblige the Iraqi government to replace the negatively healthy effects formaldehyde wood composites (medium density fiberboard MDF which are widely consumed in Iraqi markets with Wood Plastic Composites. a long-term strategy plan in which the researchers and the capitals meet under supervision of the government is very necessary and recommended in this paper to establish and develop WPCs industry in Iraq.

  15. Differentiating Agar wood Oil Quality Using Artificial Neural Network

    International Nuclear Information System (INIS)

    Nurlaila Ismail; Nor Azah Mohd Ali; Mailina Jamil; Saiful Nizam Tajuddin; Mohd Nasir Taib

    2013-01-01

    Agar wood oil is well known as expensive oil extracted from the resinous of fragrant heartwood. The oil is getting high demand in the market especially from the Middle East countries, China and Japan because of its unique odor. As part of an on-going research in grading the agar wood oil quality, the application of Artificial Neural Network (ANN) is proposed in this study to analyze agar wood oil quality using its chemical profiles. The work involves of selected agar wood oil from low and high quality, the extraction of chemical compounds using GC-MS and Z-score to identify of the significant compounds as input to the network. The ANN programming algorithm was developed and computed automatically via Matlab software version R2010a. Back-propagation training algorithm and sigmoid transfer function were used to optimize the parameters in the training network. The result obtained showed the capability of ANN in analyzing the agar wood oil quality hence beneficial for the further application such as grading and classification for agar wood oil. (author)

  16. Report of the Task Force on Sawmill Wood Residue Management

    International Nuclear Information System (INIS)

    1993-11-01

    The Sawmill Wood Residue Task Force was established in 1993 to seek solutions to managing wood residue at sawmills, shingle mills, and log sort yards in British Columbia without burning or landfilling. In particular, the Task Force was formed to address the phaseout of beehive-type wood waste burners by January 1, 1996. The Task Force was formed at the forest product industry's request and included representatives from industry associations and government. It reviewed existing information on the quantities of mill residues and the options available for reducing, reusing, and recycling the residues. Nearly half of all the province's residues of 5 million bone dry tonnes/y is disposed of by burning with no energy recovery, or by landfilling. It was recognized that the total volume of wood residue cannot be handled by any one method suitable for all sources but that in the near term, electricity generation could deal with a significant percentage of wood currently being burned. The most immediate technically viable opportnity by industry in this area may be in cogeneration of electricity for load displacement at pulp mills. Other opportunities exist such as conversion of wood residue to liquid fuels but these require greater commitments to research and development. The need to handle bark and sawdust was identified as a critical requirement for alternate uses. Small niche uses for wood residue must be examined on a case by case basis for each company or group of companies in a region. The provincial government can also promote better use of wood wastes through policies such as social costing of power generation options and sales tax exemption for ethanol fuel. 1 tab

  17. Slavic Forest, Norwegian Wood (models)

    OpenAIRE

    Rosa, Rudolf; Žabokrtský, Zdeněk; Zeman, Daniel; Mareček, David

    2017-01-01

    Trained models for UDPipe used to produce our final submission to VarDial 2017 shared task (https://bitbucket.org/hy-crossNLP/vardial2017) and described in a paper by the same authors titled Slavic Forest, Norwegian Wood.

  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. Rethinking wood dust safety standards

    OpenAIRE

    Ratnasingam, Jega; Wai, Lim Tau; Ramasamy, Geetha; Ioras, Florin; Tadin, Ishak; Universiti Putra Malaysia; Buckinghamshire New University; Centre for Occupational Safety and Health Singapore

    2015-01-01

    The current universal work safety and health standards pertaining to wood dust in factories lack the localisation required. As a study has shown, there is a urgent need to reevaluate the current guidelines and practices.

  20. Precision hole punching on composite fiber reinforced polymer panels

    Science.gov (United States)

    Abdullah, A. B.; Zain, M. S. M.; Chan, H. Y.; Samad, Z.

    2017-12-01

    Structural materials, such as composite panels, can only be assembled, and in most cases through the use of fasteners, which are fitted into the drilled holes. However, drilling is costly and time consuming, thus affecting productivity. This research aims to develop an alternative method to drilling. In this paper, the precision of the holes was measured and the effects of the die clearance to the areas around the holes were evaluated. Measurement and evaluation were performed based on the profile of the holes constructed using Alicona IFM, a 3D surface measurement technique. Results showed that punching is a potential alternative to drilling but still requires improvements.

  1. Black Hole Astrophysics The Engine Paradigm

    CERN Document Server

    Meier, David L

    2012-01-01

    As a result of significant research over the past 20 years, black holes are now linked to some of the most spectacular and exciting phenomena in the Universe, ranging in size from those that have the same mass as stars to the super-massive objects that lie at the heart of most galaxies, including our own Milky Way. This book first introduces the properties of simple isolated holes, then adds in complications like rotation, accretion, radiation, and magnetic fields, finally arriving at a basic understanding of how these immense engines work. Black Hole Astrophysics • reviews our current knowledge of cosmic black holes and how they generate the most powerful observed pheonomena in the Universe; • highlights the latest, most up-to-date theories and discoveries in this very active area of astrophysical research; • demonstrates why we believe that black holes are responsible for important phenomena such as quasars, microquasars and gammaray bursts; • explains to the reader the nature of the violent and spe...

  2. Photothermal coherence tomography for 3-D visualization and structural non-destructive imaging of a wood inlay

    Science.gov (United States)

    Tavakolian, Pantea; Sfarra, Stefano; Gargiulo, Gianfranco; Sivagurunathan, Koneshwaran; Mandelis, Andreas

    2018-06-01

    The aim of this research is to investigate the suitability of truncated correlation photothermal coherence tomography (TC-PCT) for the non-destructive imaging of a replica of a real inlay to identify subsurface features that often are invisible areas of vulnerability and damage. Defects of inlays involve glue-rich areas, glue-starved areas, termite attack, insect damage, and laminar splitting. These defects have the potential to result in extensive damage to the art design layers of inlays. Therefore, there is a need for an imaging technique to visualize and determine the location of defects within the sample. The recently introduced TC-PCT modality proved capable of providing 3-D images of specimens with high axial resolution, deep subsurface depth profiling capability, and high signal-to-noise ratio (SNR). Therefore, in this study the authors used TC-PCT to image a fabricated inlay sample with various natural and artificial defects in the middle and top layers. The inlay in question reproduces to scale a piece of art preserved in the "Mirror room" of the Castle Laffitte in France. It was built by a professional restorer following the ancient procedure named element by element. Planar TC-PCT images of the inlay were stacked coherently to provide 3-D visualization of areas with known defects in the sample. The experimental results demonstrated the identification of defects such as empty holes, a hole filled with stucco, subsurface delaminations and natural features such as a wood knot and wood grain in different layers of the sample. For this wooden sample that has a very low thermal diffusivity, a depth range of 2 mm was achieved.

  3. Fermion tunneling from higher-dimensional black holes

    International Nuclear Information System (INIS)

    Lin Kai; Yang Shuzheng

    2009-01-01

    Via the semiclassical approximation method, we study the 1/2-spin fermion tunneling from a higher-dimensional black hole. In our work, the Dirac equations are transformed into a simple form, and then we simplify the fermion tunneling research to the study of the Hamilton-Jacobi equation in curved space-time. Finally, we get the fermion tunneling rates and the Hawking temperatures at the event horizon of higher-dimensional black holes. We study fermion tunneling of a higher-dimensional Schwarzschild black hole and a higher-dimensional spherically symmetric quintessence black hole. In fact, this method is also applicable to the study of fermion tunneling from four-dimensional or lower-dimensional black holes, and we will take the rainbow-Finsler black hole as an example in order to make the fact explicit.

  4. THE MEASUREMENT AND DISTRIBUTION OF WOOD DUST

    Directory of Open Access Journals (Sweden)

    Andrea Rosario Proto

    2010-03-01

    Full Text Available In Italy, the woodworking industry presents many issues in terms of occupational health and safety. This study on exposure to wood dust could contribute to the realization of a prevention model in order to limit exposure to carcinogenic agents to the worker. The sampling methodology illustrated the analysis of dust emissions from the woodworking machinery in operation throughout the various processing cycles. The quantitative and qualitative assessment of exposure was performed using two different methodologies. The levels of wood dust were determined according to EN indications and sampling was conducted using IOM and Cyclon personal samplers. The qualitative research of wood dust was performed using an advanced laser air particle counter. This allowed the number of particles present to be counted in real time. The results obtained allowed for an accurate assessment of the quality of the dust emitted inside the workplace during the various processing phases. The study highlighted the distribution of air particles within the different size classes, the exact number of both thin and ultra-thin dusts, and confirmed the high concentration of thin dust particles which can be very harmful to humans.

  5. Natural Protection of Wood with Antagonism Fungi

    Directory of Open Access Journals (Sweden)

    Alba ZAREMSKI

    2011-03-01

    Full Text Available Biological environments contain a certain number of microbial populations which, within a givenecological niche, display various relations ranging from symbiosis to parasitism. Researchers have beeninterested in these types of relations for around fifty years, especially in one very particular type ofrelationship: the antagonism exerted between individuals of the same microbial population.Today, the role played by biological agents, bringing into play inhibitive or destructive antibioticsubstances, reveals a certain potential for their use in controlling microorganisms associated with suchdegradation processes.The work undertaken by HydroQuébec and CIRAD involved two types of experiment: 1 in Petri dishes toassess and characterize the antagonistic capacity of Trichoderma against white rot and brown rot fungi; 2on pieces taken from untreated poles in order to study confrontation between the basidiomycete and theantagonistic strain in wood.This study investigated the antagonism of three ascomycetes of the genus Trichoderma against two whiterot basidiomycetes, Pycnoporus sanguineus and Coriolus versicolor, and two brown rot basidiomycetes,Antrodia sp. and Coniophora puteana, through direct confrontation in Petri dishes and in the wood ofHydroQuébec poles.The results obtained seemed to complete each other coherently. They revealed that the Trichodermagroup of fungi was not aggressive to wood and the results obtained after direct confrontation in Petri disheswere confirmed in wood.By directly exposing the different basidiomycetes and antagonists to each other in Petri dishes, two bytwo, we effectively revealed an antagonism effect for a large majority of the pairs. However, there wassubstantial variability in reactions from one pair to the next.

  6. Variation of moisture content of some varnished woods in indoor climatic conditions

    Directory of Open Access Journals (Sweden)

    Kemal Üçüncü

    2017-11-01

    Full Text Available In this study, moisture change of varnished wood of black poplar (Populus nigra and yellow pine (Pinus silvestris L. used in indoor climate conditions with central heating in Trabzon (Turkey were investigated. 300 mm length wood specimens, with cross section of 12.5 mm in tangential and in radial and with the square sections of 25mm and 50 mm, were obtained from two species grown in Kanuni Campus of the Karadeniz Technical University. In this research, un-varnished wood samples were also used for reference. The wood moisture content was determined by the weighing method, the wood equilibrium moisture content by the Hailwood-Horrobin equation, and the relative humidity in the indoor climatic conditions by humid air thermodynamic principles. As a result; it was observed that the moisture content of varnished wood samples has a strong relationship with equilibrium moisture content, temperature and relative humidity. It was found that the moisture content of varnished woods was higher than the moisture content of un-varnished woods in the same climatic conditions. It was observed that the difference between the monthly average moisture content was lower in varnished woods in proportion to un-varnished woods. According to these results, it can be indicated that it would be more appropriate to select higher moisture content in the drying of wood than the equilibrium moisture content. Such an application would also reduce drying costs. Further, it can be recommended to use varnished wood in various applications because the low change range of average moisture content can affect the swelling or shrinking of wood.

  7. Efficiency analysis of wood processing industry in China during 2006-2015

    Science.gov (United States)

    Zhang, Kun; Yuan, Baolong; Li, Yanxuan

    2018-03-01

    The wood processing industry is an important industry which affects the national economy and social development. The data envelopment analysis model (DEA) is a quantitative evaluation method for studying industrial efficiency. In this paper, the wood processing industry of 8 provinces in southern China is taken as the study object, and the efficiency of each province in 2006 to 2015 was measured and calculated with the DEA method, and the efficiency changes, technological changes and Malmquist index were analyzed dynamically. The empirical results show that there is a widening gap in the efficiency of wood processing industry of the 8 provinces, and the technological progress has shown a lag in the promotion of wood processing industry. According to the research conclusion, along with the situation of domestic and foreign wood processing industry development, the government must introduce relevant policies to strengthen the construction of the wood processing industry technology innovation policy system and the industrial coordinated development system.

  8. Nonsingular black hole

    Energy Technology Data Exchange (ETDEWEB)

    Chamseddine, Ali H. [American University of Beirut, Physics Department, Beirut (Lebanon); I.H.E.S., Bures-sur-Yvette (France); Mukhanov, Viatcheslav [Niels Bohr Institute, Niels Bohr International Academy, Copenhagen (Denmark); Ludwig-Maximilians University, Theoretical Physics, Munich (Germany); MPI for Physics, Munich (Germany)

    2017-03-15

    We consider the Schwarzschild black hole and show how, in a theory with limiting curvature, the physical singularity ''inside it'' is removed. The resulting spacetime is geodesically complete. The internal structure of this nonsingular black hole is analogous to Russian nesting dolls. Namely, after falling into the black hole of radius r{sub g}, an observer, instead of being destroyed at the singularity, gets for a short time into the region with limiting curvature. After that he re-emerges in the near horizon region of a spacetime described by the Schwarzschild metric of a gravitational radius proportional to r{sub g}{sup 1/3}. In the next cycle, after passing the limiting curvature, the observer finds himself within a black hole of even smaller radius proportional to r{sub g}{sup 1/9}, and so on. Finally after a few cycles he will end up in the spacetime where he remains forever at limiting curvature. (orig.)

  9. When Black Holes Collide

    Science.gov (United States)

    Baker, John

    2010-01-01

    Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

  10. Where there's smoke : health effects of wood smoke and risk reduction strategies

    Energy Technology Data Exchange (ETDEWEB)

    MacKinnon, B. [New Brunswick Lung Association, Fredericton, NB (Canada)

    2005-07-01

    This paper presents a summary of a discussion at a former workshop on smoke from both forest fires and wood stoves. Climate change is forecasted to increase the occurrence of forest fires in Canada and climate change mitigation measures may increase the use of wood stoves for home heating, resulting in an increase in respiratory and cardiovascular symptoms in the Canadian population. These health effects of wood smoke include: headaches and allergies; breathing difficulties; reduced lung function; aggravated heart disease; and increased susceptibility to lower respiratory tract infections. This paper also presented information on health effects of wood smoke and research recommendations for improved policies to protect human health. tabs., figs.

  11. The Thermodynamic Relationship between the RN-AdS Black Holes and the RN Black Hole in Canonical Ensemble

    Directory of Open Access Journals (Sweden)

    Yu-Bo Ma

    2017-01-01

    Full Text Available In this paper, by analyzing the thermodynamic properties of charged AdS black hole and asymptotically flat space-time charged black hole in the vicinity of the critical point, we establish the correspondence between the thermodynamic parameters of asymptotically flat space-time and nonasymptotically flat space-time, based on the equality of black hole horizon area in the two different types of space-time. The relationship between the cavity radius (which is introduced in the study of asymptotically flat space-time charged black holes and the cosmological constant (which is introduced in the study of nonasymptotically flat space-time is determined. The establishment of the correspondence between the thermodynamics parameters in two different types of space-time is beneficial to the mutual promotion of different time-space black hole research, which is helpful to understand the thermodynamics and quantum properties of black hole in space-time.

  12. Hydrodynamic and hydromagnetic stability of black holes with ...

    Indian Academy of Sciences (India)

    ... research career – radiative transfer, magnetohydrodynamics and black holes .... icant parts of a jet that happen to maximize the Lorentz factor while including us ... The choice for the momentum carrier is between electromagnetic field and ..... possible to understand, at least qualitatively, the influence of black hole spin and.

  13. Gas flow parameters in laser cutting of wood- nozzle design

    Science.gov (United States)

    Kali Mukherjee; Tom Grendzwell; Parwaiz A.A. Khan; Charles McMillin

    1990-01-01

    The Automated Lumber Processing System (ALPS) is an ongoing team research effort to optimize the yield of parts in a furniture rough mill. The process is designed to couple aspects of computer vision, computer optimization of yield, and laser cutting. This research is focused on optimizing laser wood cutting. Laser machining of lumber has the advantage over...

  14. Evaluating the Environmental Performance of Wood-Based Biofuels

    Science.gov (United States)

    Bruce Lippke; Richard Bergman; Adam Taylor; Maureen E. Puettmann

    2012-01-01

    The nonprofit Consortium for Research on Renewable Industrial Materials (CORRIM) has been developing comprehensive environmental performance information on wood building materials consistent with life-cycle standards (http://www.corrim.org/). The articles published in this Special Issue of the Forest Products Journal extend the research by the...

  15. Black holes and quantum mechanics

    CERN Document Server

    Wilczek, Frank

    1995-01-01

    1. Qualitative introduction to black holes : classical, quantum2. Model black holes and model collapse process: The Schwarzschild and Reissner-Nordstrom metrics, The Oppenheimer-Volkov collapse scenario3. Mode mixing4. From mode mixing to radiance.

  16. Quantum Mechanics of Black Holes

    OpenAIRE

    Giddings, Steven B.

    1994-01-01

    These lectures give a pedagogical review of dilaton gravity, Hawking radiation, the black hole information problem, and black hole pair creation. (Lectures presented at the 1994 Trieste Summer School in High Energy Physics and Cosmology)

  17. Aspects of hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Anabalón, Andrés, E-mail: andres.anabalon-at@uai.cl [Departamento de Ciencias, Facultad de Artes Liberales y Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar (Chile); Astefanesei, Dumitru [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile)

    2015-03-26

    We review the existence of exact hairy black holes in asymptotically flat, anti-de Sitter and de Sitter space-times. We briefly discuss the issue of stability and the charging of the black holes with a Maxwell field.

  18. Life cycle environmental impacts of different construction wood waste and wood packaging waste processing methods

    OpenAIRE

    Manninen, Kaisa; Judl, Jáchym; Myllymaa, Tuuli

    2016-01-01

    This study compared the life cycle environmental impacts of different wood waste processing methods in three impact categories: climate impact, acidification impacts and eutrophication impacts. The wood waste recovery methods examined were the use of wood waste in terrace boards made out of wood composite which replace impregnated terrace boards, incineration of wood waste in a multi-fuel boiler instead of peat and the use of wood waste in the production of particleboard in either Finland or ...

  19. Occurrence patterns of dead wood and wood-dependent lichens in managed boreal forest landscapes

    OpenAIRE

    Svensson, Måns

    2013-01-01

    Dead wood is a key resource for biodiversity, on which thousands of forest organisms are dependent. Because of current forest management, there has been a large-scale change in dead wood amounts and qualities, and consequently, many wood-dependent species are threatened. The general aim of this thesis is to increase our understanding of habitat requirements and occurrence patterns of wood-dependent lichens in managed, boreal forest landscapes. We surveyed dead wood and wood-dependent lichens ...

  20. Jets, black holes and disks in blazars

    Directory of Open Access Journals (Sweden)

    Ghisellini Gabriele

    2013-12-01

    Full Text Available The Fermi and Swift satellites, together with ground based Cherenkov telescopes, has greatly improved our knowledge of blazars, namely Flat Spectrum Radio Quasars and BL Lac objects, since all but the most powerful emit most of their electro–magnetic output at γ–ray energies, while the very powerful blazars emit mostly in the hard X–ray region of the spectrum. Often they show coordinated variability at different frequencies, suggesting that in these cases the same population of electrons is at work, in a single zone of the jet. The location of this region along the jet is a matter of debate. The jet power correlates with the mass accretion rate, with jets existing at all values of disk luminosities, measured in Eddington units, sampled so far. The most powerful blazars show clear evidence of the emission from their disks, and this has revived methods of finding the black hole mass and accretion rate by modelling a disk spectrum to the data. Being so luminous, blazars can be detected also at very high redshift, and therefore are a useful tool to explore the far universe. One interesting line of research concerns how heavy are their black holes at high redshifts. If we associate the presence of a relativistic jets with a fastly spinning black hole, then we naively expect that the accretion efficiency is larger than for non–spinning holes. As a consequence, the black hole mass in jetted systems should grow at a slower rate. In turn, this would imply that, at high redshifts, the heaviest black holes should be in radio–quiet quasars. We instead have evidences of the opposite, challenging our simple ideas of how a black hole grows.

  1. Effect of cement/wood ratios and wood storage conditions on hydration temperature, hydration time, and compressive strength of wood-cement mixtures

    Science.gov (United States)

    Andy W.C. Lee; Zhongli Hong; Douglas R. Phillips; Chung-Yun Hse

    1987-01-01

    This study investigated the effect of cement/wood ratios and wood storage conditions on hydration temperature, hydration time, and compressive strength of wood-cement mixtures made from six wood species: southern pine, white oak, southern red oak, yellow-poplar, sweetgum, and hickory. Cement/wood ratios varied from 13/1 to 4/1. Wood storage conditions consisted of air-...

  2. Neutrino constraints that transform black holes into grey holes

    International Nuclear Information System (INIS)

    Ruderfer, M.

    1982-01-01

    Existing black hole theory is found to be defective in its neglect of the physical properties of matter and radiation at superhigh densities. Nongravitational neutrino effects are shown to be physically relevant to the evolution of astronomical black holes and their equations of state. Gravitational collapse to supernovae combined with the Davis and Ray vacuum solution for neutrinos limit attainment of a singularity and require black holes to evolve into ''grey holes''. These allow a better justification than do black holes for explaining the unique existence of galactic masses. (Auth.)

  3. Warped products and black holes

    International Nuclear Information System (INIS)

    Hong, Soon-Tae

    2005-01-01

    We apply the warped product space-time scheme to the Banados-Teitelboim-Zanelli black holes and the Reissner-Nordstroem-anti-de Sitter black hole to investigate their interior solutions in terms of warped products. It is shown that there exist no discontinuities of the Ricci and Einstein curvatures across event horizons of these black holes

  4. Magnetohydrodynamics near a black hole

    International Nuclear Information System (INIS)

    Wilson, J.R.

    1975-01-01

    A numerical computer study of hydromagnetic flow near a black hole is presented. First, the equations of motion are developed to a form suitable for numerical computations. Second, the results of calculations describing the magnetic torques exerted by a rotating black hole on a surrounding magnetic plasma and the electric charge that is induced on the surface of the black hole are presented. (auth)

  5. Black Holes and the Large Hadron Collider

    Science.gov (United States)

    Roy, Arunava

    2011-01-01

    The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

  6. Black hole entropy and finite geometry

    Czech Academy of Sciences Publication Activity Database

    Levay, P.; Saniga, M.; Vrana, P.; Pracna, Petr

    2009-01-01

    Roč. 79, č. 8 (2009), 084036 ISSN 1550-7998 Institutional research plan: CEZ:AV0Z40400503 Keywords : Maxwell-Einstein supergravity * attractors * black hole entropy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.922, year: 2009

  7. Providing Undergraduate Research Opportunities Through the World Rivers Observatory Collaborative Network

    Science.gov (United States)

    Gillies, S. L.; Marsh, S. J.; Janmaat, A.; Peucker-Ehrenbrink, B.; Voss, B.; Holmes, R. M.

    2013-12-01

    Successful research collaboration exists between the University of the Fraser Valley (UFV), a primarily undergraduate-serving university located on the Fraser River in British Columbia, and the World Rivers Observatory that is coordinated through the Woods Hole Oceanographic Institution (WHOI) and the Woods Hole Research Center (WHRC). The World Rivers Observatory coordinates time-series sampling of 15 large rivers, with particular focus on the large Arctic rivers, the Ganges-Brahmaputra, Congo, Fraser, Yangtze (Changjiang), Amazon, and Mackenzie River systems. The success of this international observatory critically depends on the participation of local collaborators, such as UFV, that are necessary in order to collect temporally resolved data from these rivers. Several faculty members and undergraduate students from the Biology and Geography Departments of UFV received on-site training from the lead-PIs of the Global Rivers Observatory. To share information and ensure good quality control of sampling methods, WHOI and WHRC hosted two international workshops at Woods Hole for collaborators. For the past four years, faculty and students from UFV have been collecting a variety of bi-monthly water samples from the Fraser River for the World Rivers Observatory. UFV undergraduate students who become involved learn proper sampling techniques and are given the opportunity to design and conduct their own research. Students have collected, analyzed and presented data from this project at regional, national, and international scientific meetings. UFV undergraduate students have also been hosted by WHOI and WHRC as guest students to work on independent research projects. While at WHOI and WHRC, students are able to conduct research using state-of-the-art specialized research facilities not available at UFV.

  8. 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.

  9. 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...... of different aspects relevant to wood combustion, including wood structure and composition, wood pyrolysis, wood char properties and wood char oxidation. The full scale campaign, which is the subject of Chapter 3, included sampling of wood fuel before and after milling and sampling of gas and particles...... at the top of the combustion chamber. The collected samples and data are used to obtain an evaluation of the mills in operation at the power plant, the particle size distribution of the wood fuel, as well as the char conversion attained in the furnace. In Chapter 4 an experimental investigation...

  10. Evolving Coronal Holes and Interplanetary Erupting Stream ...

    Indian Academy of Sciences (India)

    prominences, have a significantly higher rate of occurrence in the vicinity of coronal .... coronal holes due to the birth of new holes or the growth of existing holes. .... Statistics of newly formed coronal hole areas (NFOCHA) associated with ...

  11. From binary black hole simulation to triple black hole simulation

    International Nuclear Information System (INIS)

    Bai Shan; Cao Zhoujian; Han, Wen-Biao; Lin, Chun-Yu; Yo, Hwei-Jang; Yu, Jui-Ping

    2011-01-01

    Black hole systems are among the most promising sources for a gravitational wave detection project. Now, China is planning to construct a space-based laser interferometric detector as a follow-on mission of LISA in the near future. Aiming to provide some theoretical support to this detection project on the numerical relativity side, we focus on black hole systems simulation in this work. Considering the globular galaxy, multiple black hole systems also likely to exist in our universe and play a role as a source for the gravitational wave detector we are considering. We will give a progress report in this paper on our black hole system simulation. More specifically, we will present triple black hole simulation together with binary black hole simulation. On triple black hole simulations, one novel perturbational method is proposed.

  12. Production facility site selection factors for Texas value-added wood producers

    Science.gov (United States)

    Judd H. Michael; Joanna Teitel; James E. Granskog

    1998-01-01

    Value-added wood products manufacturers serve an important role in the economies of many U.S. regions and are therefore sought after by entities such as economic development agencies. The reasons why certain locations for a prospective prodution facility would be more attractive to secondary wood industry producers are not clearly understood. Therefore, this research...

  13. Thermal properties of wood reacted with a phosphorus pentoxide–amine system

    Science.gov (United States)

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

    2004-01-01

    The objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide–amine system. Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. The characteristics of...

  14. Life cycle impacts of forest management and wood utilization on carbon mitigation : knowns and unknowns

    Science.gov (United States)

    Bruce Lippke; Elaine Oneil; Rob Harrison; Kenneth Skog; Leif Gustavsson; Roger Sathre

    2011-01-01

    This review on research on life cycle carbon accounting examines the complexities in accounting for carbon emissions given the many different ways that wood is used. Recent objectives to increase the use of renewable fuels have raised policy questions, with respect to the sustainability of managing our forests as well as the impacts of how best to use wood from our...

  15. Recent activities in flame retardancy of wood-plastic composites at the Forest Products Laboratory

    Science.gov (United States)

    Robert H. White; Nicole M. Stark; Nadir Ayrilmis

    2011-01-01

    For a variety of reasons, wood-plastic composite (WPC) products are widely available for some building applications. In applications such as outdoor decking, WPCs have gained a significant share of the market. As an option to improve the efficient use of wood fiber, the USDA Forest Service, Forest Products Laboratory (FPL), has an extensive research program on WPCs....

  16. Chemical yields from low-temperature pyrolysis of CCA-treated wood

    Science.gov (United States)

    Qirong Fu; Dimitris Argyropolous; Lucian Lucia; David Tilotta; Stan Lebow

    2009-01-01

    Low-temperature pyrolysis offers a feasible option for wood-waste management and the recovery of a variety of useful chemicals. The effect of chromated copper arsenate (CCA) wood preservative on the yield and composition of various pyrolysis products was investigated in the present research. A novel quantitative 31P nuclear magnetic resonance (...

  17. The wood properties and sawn-board quality of South African-grown ...

    African Journals Online (AJOL)

    This report summarises results of past research in South Africa on the wood properties and qualities of P. maximinoi, supplemented by results of a study performed recently on an approximately 15.5-year-old provenance trial at Wilgeboom after it had been severely damaged by fire. The trees selected to study wood density, ...

  18. Effects of species information and furniture price on consumer preferences for selected woods

    Science.gov (United States)

    Matthew Bumgardner; David Nicholls; Geoffrey Donovan

    2007-01-01

    Changing consumer tastes and species availability are influencing the design and manufacture of hardwood products. In addition, the globalization of wood product markets is exposing U.S. consumers to new species. This research evaluates consumer preferences for six domestic wood species--three from the eastern United States and three from the western United States. The...

  19. 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

  20. Wood versus plant fibers: Similarities and differences in composite applications

    DEFF Research Database (Denmark)

    Madsen, Bo; Gamstedt, E. Kristofer

    2013-01-01

    -negligible porosity content, and finally, the moisture sensitivity of the composites. The performance of wood and plant fiber composites is compared to the synthetic glass and carbon fibers conventionally used for composites, and advantages and disadvantages of the different fibers are discussed. © 2013 Bo Madsen......The work on cellulose fiber composites is typically strictly divided into two separated research fields depending on the fiber origin, that is, from wood and from annual plants, representing the two different industries of forest and agriculture, respectively. The present paper evaluates...... in parallel wood fibers and plant fibers to highlight their similarities and differences regarding their use as reinforcement in composites and to enable mutual transfer of knowledge and technology between the two research fields. The paper gives an introduction to the morphology, chemistry...

  1. Wood fuels consumption in households in Montenegro

    Directory of Open Access Journals (Sweden)

    Glavonjić Branko D.

    2013-01-01

    Full Text Available The paper presents the results of researching wood fuels consumption in households in Montenegro in the heating season 2011/2012. The research was conducted in the period October-November 2012 on the sample of 5% of the total number of households which stated to use solid fuels for heating purposes in the 2011 census. Results of the conducted researches on the presence and amounts of fuels consumed in households in Montenegro showed that total firewood consumption in the heating season 2011/2012 (both urban and rural households was 703,571 m3. Wood consumption is the lowest in the households in the municipalities in the coastal zone, it is somewhat higher in central zone and the highest in the zone on the north of Montenegro. Average wood consumption in households in the coastal zone municipalities is 3.79 m3, in the central zone it is 5.02 m3 and on the north of Montenegro it is 6.74 m3/household. Observed on the level of Montenegro, average firewood consumption per household was 5.49 m3 and as such it best represents relatively low consumption level in the coastal zone and high consumption level on the north of Montenegro. Compared to the neighboring countries, average firewood consumption per household in Montenegro in the amount of 5.49 m3 is significantly lower than the average consumption in Serbia which is 7.3 m3/household as well as in Slovenia in the amount of 6.5 m3.

  2. Bio-Based Adhesives and Evaluation for Wood Composites Application

    Directory of Open Access Journals (Sweden)

    Fatemeh Ferdosian

    2017-02-01

    Full Text Available There has been a rapid growth in research and innovation of bio-based adhesives in the engineered wood product industry. This article reviews the recent research published over the last few decades on the synthesis of bio-adhesives derived from such renewable resources as lignin, starch, and plant proteins. The chemical structure of these biopolymers is described and discussed to highlight the active functional groups that are used in the synthesis of bio-adhesives. The potentials and drawbacks of each biomass are then discussed in detail; some methods have been suggested to modify their chemical structures and to improve their properties including water resistance and bonding strength for their ultimate application as wood adhesives. Moreover, this article includes discussion of techniques commonly used for evaluating the petroleum-based wood adhesives in terms of mechanical properties and penetration behavior, which are expected to be more widely applied to bio-based wood adhesives to better evaluate their prospect for wood composites application.

  3. 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)

  4. Statistical mechanics of black holes

    International Nuclear Information System (INIS)

    Harms, B.; Leblanc, Y.

    1992-01-01

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black-hole decay and of quantum coherence are also addressed

  5. Black Holes and Firewalls

    Science.gov (United States)

    Polchinski, Joseph

    2015-04-01

    Our modern understanding of space, time, matter, and even reality itself arose from the three great revolutions of the early twentieth century: special relativity, general relativity, and quantum mechanics. But a century later, this work is unfinished. Many deep connections have been discovered, but the full form of a unified theory incorporating all three principles is not known. Thought experiments and paradoxes have often played a key role in figuring out how to fit theories together. For the unification of general relativity and quantum mechanics, black holes have been an important arena. I will talk about the quantum mechanics of black holes, the information paradox, and the latest version of this paradox, the firewall. The firewall points to a conflict between our current theories of spacetime and of quantum mechanics. It may lead to a new understanding of how these are connected, perhaps based on quantum entanglement.

  6. Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

    Science.gov (United States)

    Guo, Feihong; Zhong, Zhaoping

    2018-08-01

    This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Beyond the black hole

    International Nuclear Information System (INIS)

    Boslough, J.

    1985-01-01

    This book is about the life and work of Stephen Hawking. It traces the development of his theories about the universe and particularly black holes, in a biographical context. Hawking's lecture 'Is the end in sight for theoretical physics' is presented as an appendix. In this, he discusses the possibility of achieving a complete, consistent and unified theory of the physical interactions which would describe all possible observations. (U.K.)

  8. Bumpy black holes

    OpenAIRE

    Emparan, Roberto; Figueras, Pau; Martinez, Marina

    2014-01-01

    We study six-dimensional rotating black holes with bumpy horizons: these are topologically spherical, but the sizes of symmetric cycles on the horizon vary non-monotonically with the polar angle. We construct them numerically for the first three bumpy families, and follow them in solution space until they approach critical solutions with localized singularities on the horizon. We find strong evidence of the conical structures that have been conjectured to mediate the transitions to black ring...

  9. Internal structure of black holes

    International Nuclear Information System (INIS)

    Cvetic, Mirjam

    2013-01-01

    Full text: We review recent progress that sheds light on the internal structure of general black holes. We first summarize properties of general multi-charged rotating black holes both in four and five dimensions. We show that the asymptotic boundary conditions of these general asymptotically flat black holes can be modified such that a conformal symmetry emerges. These subtracted geometries preserve the thermodynamic properties of the original black holes and are of the Lifshitz type, thus describing 'a black hole in the asymptotically conical box'. Recent efforts employ solution generating techniques to construct interpolating geometries between the original black hole and their subtracted geometries. Upon lift to one dimension higher, these geometries lift to AdS 3 times a sphere, and thus provide a microscopic interpretation of the black hole entropy in terms of dual two-dimensional conformal field theory. (author)

  10. Black holes and holography

    International Nuclear Information System (INIS)

    Mathur, Samir D

    2012-01-01

    The idea of holography in gravity arose from the fact that the entropy of black holes is given by their surface area. The holography encountered in gauge/gravity duality has no such relation however; the boundary surface can be placed at an arbitrary location in AdS space and its area does not give the entropy of the bulk. The essential issues are also different between the two cases: in black holes we get Hawking radiation from the 'holographic surface' which leads to the information issue, while in gauge/gravity duality there is no such radiation. To resolve the information paradox we need to show that there are real degrees of freedom at the horizon of the hole; this is achieved by the fuzzball construction. In gauge/gravity duality we have instead a field theory defined on an abstract dual space; there are no gravitational degrees of freedom at the holographic boundary. It is important to understand the relations and differences between these two notions of holography to get a full understanding of the lessons from the information paradox.

  11. Wood bioenergy and soil productivity research

    Science.gov (United States)

    D. Andrew Scott; Deborah S. Page-Dumroese

    2016-01-01

    Timber harvesting can cause both short- and long-term changes in forest ecosystem functions, and scientists from USDA Forest Service (USDA FS) have been studying these processes for many years. Biomass and bioenergy markets alter the amount, type, and frequency at which material is harvested, which in turn has similar yet specific impacts on sustainable productivity....

  12. Stephen C. Woods: a precocious scientist.

    Science.gov (United States)

    Smith, Gerard P

    2011-04-18

    To investigate the early scientific development of Steve Woods, I reviewed his research during the first decade after he received his doctoral degree in 1970. The main parts of his research program were conditioned insulin secretion and hypoglycemia, Pavlovian conditioning of insulin secretion before a scheduled access to food, and basal insulin as a negative-feedback signal from fat mass to the brain. These topics were pursued with experimental ingenuity; the resulting publications were interesting, clear, and rhetorically effective. Although the theoretical framework for his experiments with insulin was homeostatic, by the end of the decade he suggested that classic negative-feedback homeostasis needed to be revised to include learning acquired by lifestyle. Thus, Woods functioned as a mature scientist from the beginning of his research-he was very precocious. This precocity also characterized his teaching and mentoring as recalled by two of his students during that time, Joseph Vasselli and Paul Kulkosky. The most unusual and exemplary aspect of his precocity is that the outstanding performance of his first decade was maintained during the subsequent 30years. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. On the evaluation of semiclassical nuclear many-particle many-hole level densities

    International Nuclear Information System (INIS)

    Blin, A.H.; Hiller, B.; Schuck, P.; Yannouleas, C.

    1985-10-01

    An exact general scheme is described to calculate the m-particle n-hole fermion level densities for an arbitrary single particle Hamiltonian taking into account the Pauli exclusion principle. This technique is applied to obtain level densities of the three dimensional isotropic harmonic oscillator semiclassically in the Thomas-Fermi approach. In addition, we study the l-particle l-hole level density of the Woods-Saxon potential. For the harmonic oscillator we analyze the temperature dependence of the linear response function and the influence of pairing correlations on the l-particle l-hole level density. Finally, a Taylor expansion method of the m-particle n-hole level densities is discussed

  14. Improvements to the Understanding of the Fire Performance of Wood over the Past 30 Years-A Tribute to Robert Hawthorne White

    Science.gov (United States)

    Samuel L. Zelinka; Mark A. Dietenberger; Laura E. Hasburgh; Keith J. Bourne; Charles Boardman

    2015-01-01

    Dr. Robert Hawthorne White had a 31 year career researching the fire performance of wood and wood composites at the USDA Forest Products Laboratory. Over his career, Dr. White made substantial contributions to codes, standards, and regulations pertaining to the design of wood structures. This review article summarizes Robert’s major accomplishments as a tribute to his...

  15. Liquefaction of aspen poplar wood

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Mathews, J F; Pepper, J M

    1982-01-01

    Dried and green aspen poplar wood suspended in water containing alkali catalysts was converted completely to an oil, water-soluble chemical, and gases by heating for 1 hour in the presence of CO in a rocking batch reactor. Within the ranges of parameters studied: temperature of 593-633 K; nominal reaction times of less than or equal to 1 hour; water-to-wood ratio of 0.5:1-5:1; Na/sub 2/CO/sub 3/, K/sub 2/CO/sub 3/, and NaOH catalysts; amount of catalyst 7.0-12.5%; and initial H-CO ratios of 2:1-0:1, the water-to-wood ratio was most important. Oil yields of approximately 50% with a C plus H content of approximately 80% and representing a C recovery of approximately 66% were obtained. The higher heats of combustion were 32.2-36.0 MJ/kg.

  16. 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.

  17. Wood-burning stoves worldwide

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo

    global environmental health risk, since these sources are important contributors to fine particulate matter (PM2.5) in the ambient air that increase climate and health risks. This thesis explores the social-technical dimensions of both the use of wood-burning stoves (WBSs) and transition to the use......More than any time in our history, the wood-burning stove continues to be the most popular technology used for cooking and heating worldwide. According to the World Health Organization and recent scientific studies, the inefficient use of solid-fuels in traditional stoves constitutes the major...... systems, improved efficient retrofits and advanced stove innovations. In chapter 3, four popular wood-burning practices found in five countries were singled-out to be examined closely in four case studies: “cooking in Brazil”, “cooking and heating in Peru”, “heating in Portugal” and “recreational heat...

  18. Agrilus auroguttatus exit hole distributions on Quercus agrifolia boles and a sampling method to estimate their density on individual trees

    Science.gov (United States)

    Laurel J. Haavik; Tom W. Coleman; Mary Louise Flint; Robert C. Venette; Steven J. Seybold

    2012-01-01

    In recent decades, invasive phloem and wood borers have become important pests in North America. To aid tree sampling and survey efforts for the newly introduced goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), we examined spatial patterns of exit holes on the boles (trunks) of 58 coast live oak, Quercus...

  19. Determining wood chip size: image analysis and clustering methods

    Directory of Open Access Journals (Sweden)

    Paolo Febbi

    2013-09-01

    Full Text Available One of the standard methods for the determination of the size distribution of wood chips is the oscillating screen method (EN 15149- 1:2010. Recent literature demonstrated how image analysis could return highly accurate measure of the dimensions defined for each individual particle, and could promote a new method depending on the geometrical shape to determine the chip size in a more accurate way. A sample of wood chips (8 litres was sieved through horizontally oscillating sieves, using five different screen hole diameters (3.15, 8, 16, 45, 63 mm; the wood chips were sorted in decreasing size classes and the mass of all fractions was used to determine the size distribution of the particles. Since the chip shape and size influence the sieving results, Wang’s theory, which concerns the geometric forms, was considered. A cluster analysis on the shape descriptors (Fourier descriptors and size descriptors (area, perimeter, Feret diameters, eccentricity was applied to observe the chips distribution. The UPGMA algorithm was applied on Euclidean distance. The obtained dendrogram shows a group separation according with the original three sieving fractions. A comparison has been made between the traditional sieve and clustering results. This preliminary result shows how the image analysis-based method has a high potential for the characterization of wood chip size distribution and could be further investigated. Moreover, this method could be implemented in an online detection machine for chips size characterization. An improvement of the results is expected by using supervised multivariate methods that utilize known class memberships. The main objective of the future activities will be to shift the analysis from a 2-dimensional method to a 3- dimensional acquisition process.

  20. 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

  1. Black Hole Hunters Set New Distance Record

    Science.gov (United States)

    2010-01-01

    billion times as much as the Sun. So far, around 20 stellar-mass black holes have been found. [2] In astronomy, heavy chemical elements, or "metals", are any chemical elements heavier than helium. [3] Predicted by Einstein's theory of general relativity, gravitational waves are ripples in the fabric of space and time. Significant gravitational waves are generated whenever there are extreme variations of strong gravitational fields with time, such as during the merger of two black holes. The detection of gravitational waves, never directly observed to date, is one of the major challenges for the next few decades. [4] The LIGO and Virgo experiments have the goal of detecting gravitational waves using sensitive interferometers in Italy and the United States. More information This research was presented in a letter to appear in the Monthly Notices of the Royal Astronomical Society (NGC 300 X-1 is a Wolf-Rayet/Black Hole binary, P.A. Crowther et al.). The team is composed of Paul Crowther and Vik Dhillon (University of Sheffield, UK), Robin Barnard and Simon Clark (The Open University, UK), and Stefania Carpano and Andy Pollock (ESAC, Madrid, Spain). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible

  2. Controls on coarse wood decay in temperate tree species: birth of the LOGLIFE experiment.

    Science.gov (United States)

    Cornelissen, Johannes H C; Sass-Klaassen, Ute; Poorter, Lourens; van Geffen, Koert; van Logtestijn, Richard S P; van Hal, Jurgen; Goudzwaard, Leo; Sterck, Frank J; Klaassen, René K W M; Freschet, Grégoire T; van der Wal, Annemieke; Eshuis, Henk; Zuo, Juan; de Boer, Wietse; Lamers, Teun; Weemstra, Monique; Cretin, Vincent; Martin, Rozan; Ouden, Jan den; Berg, Matty P; Aerts, Rien; Mohren, Godefridus M J; Hefting, Mariet M

    2012-01-01

    Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term 'common-garden' experiment to disentangle the effects of species' wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 tree species. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation.

  3. Development of wood pellets market in South East Europe

    Directory of Open Access Journals (Sweden)

    Glavonjić Branko D.

    2015-01-01

    Full Text Available The paper presents the results of researching wood pellets market in nine countries in South East Europe and Slovakia. Objective of the research was to observe the actual situation regarding the number of producers, size of installed capacities, production volume, foreign trade flows and existing problems and obstacles which significantly limit the sustainable development of wood pellets market in the selected countries. Selection of such an objective results from the fact that according to the stated elements there are no sufficiently reliable data, wherefore this region is a huge gap in numerous reports of international and national organizations and institutions. Results of the conducted research show that in the middle of 2014, 245 producers were engaged in wood pellets production in South East Europe and Slovakia, 116 of which were located in Bulgaria and Serbia. Most of the producers of wood pellets has installed capacities of 1,000-5,000 tons annually, while only 18 factories in the entire region have the installed capacity over 30,000 tons/year. Observed collectively in all stated countries, the total installed capacities for wood pellets production were 2.2 million tons in 2013 and the realized production was 1.36 million tons. The largest part of the produced amounts of wood pellets in this region is exported. 1.06 million tons were exported from the region in 2013, which is 77.9% of the realized production. Such high export is the result of the underdevelopment of the local market (Slovenia is the only exception and the problems which exist and limit its faster development in most countries.

  4. 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.

  5. Three Construction Projects with Wood Scraps

    Science.gov (United States)

    Levine, Elizabeth

    1977-01-01

    Wood, a natural material, appeals to children of all ages. Wood construction allows children the flexibility of moving parts of their work around until they are satisfied with the arrangement. Three projects are described. (Author/RK)

  6. The environmental assessment of the wood combustion

    International Nuclear Information System (INIS)

    Dinca, Cristian; Badea, Adrian; Apostol, Tiberiu

    2007-01-01

    In this paper, the authors analysed the emissions from residential boilers burning wood logs, bark pellets, wood briquettes and wood pellets. Three boilers, selected with respect to age, design, connection to heat storage tank, and type of biofuel, were included in the study. The emissions captured comprised carbon monoxide (CO), carbon dioxide (CO 2 ), oxygen (O 2 ), total organic carbons (TOC), nitrogen oxides (NO x ), polycyclic aromatic hydrocarbons (PAC) and 33 volatile organic compounds (VOC). We have used the Life Cycle Inventory method in order to identify the main stressors generated by the wood combustion stage. In this purpose, we have analysed one type of old boiler, one type of modern boiler and a multi-fuel boiler, which can burn wood logs, bark pellets, wood briquettes and wood pellets. In this article, we selected only the wood combustion stage because it is the most important according to the emissions produced. (authors)

  7. Photodegradation of wood and depth profile analysis

    International Nuclear Information System (INIS)

    Kataoka, Y.

    2008-01-01

    Photochemical degradation is a key process of the weathering that occurs when wood is exposed outdoors. It is also a major cause of the discoloration of wood in indoor applications. The effects of sunlight on the chemical composition of wood are superficial in nature, but estimates of the depth at which photodegradation occurs in wood vary greatly from 80 microm to as much as 2540 mic rom. Better understanding of the photodegradation of wood through depth profile analysis is desirable because it would allow the development of more effective photo-protective treatments that target the surface layers of wood most susceptible to photodegradation. This paper briefly describes fundamental aspects of photodegradation of wood and reviews progress made in the field of depth profile study on the photodegradation of wood. (author)

  8. 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.

  9. Forest industry wood fuel supply

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The potential for wood fired energy production in the UK is significant. Large scale developments are currently underway which could utilise over 100,000 green tonnes of forest residues. The fuel supply chain is likely to be complicated and there are perceived risks in its organisation and security. This report sets out to address some of these perceived risks and suggest suitable measures to reduce it. Six areas of the fuel supply chain have been studied, namely; Extraction, Comminution, Transport, Assessment and payment of wood fuel; Environmental impact; Nutrient recycling (ash disposal). (author)

  10. 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.)

  11. Wood fuelled boiler operating costs

    International Nuclear Information System (INIS)

    Sandars, D.L.

    1995-01-01

    This report is a management study into the operating costs of wood-fired boilers. Data obtained from existing wood-fired plant has been analysed and interpreted using the principles of machinery management and the science that underlies the key differences between this fuel and any other. A set of budgeting principles has been developed for the key areas of labour requirement, insurance, maintenance and repair and electricity consumption. Other lesser cost centres such as the provision of shelter and the effects of neglect and accidents have also been considered, and a model constructed. (author)

  12. Preparation of coloured wood plastics

    International Nuclear Information System (INIS)

    Lebedev, V.T.; Filippova, T.G.; Rajchuk, F.Z.

    1977-01-01

    A study has been made into the possibility of using fat, as well as alcohol- and water-soluble dyes for radiation-chemical dying of polymers and plastics filled with wood. The use of fat-soluble azo and anthraquinone dyes permits obtaining intensely colored wood-plastic materials based on methyl methacrylate by way of gamma radiation with doses of up to 3 Mrad. At a dose above 5 Mrad, a marked tarnishing of the dye or a change in color and stains are observed. Dyes in styrene withstand higher radiation doses without any significant destruction

  13. Wood pellets for stoker burner

    International Nuclear Information System (INIS)

    Nykaenen, S.

    2000-01-01

    The author of this article has had a stoker for several years. Wood chips and sod peat has been used as fuels in the stoker, either separately or mixed. Last winter there occurred problems with the sod peat due to poor quality. Wood pellets, delivered by Vapo Oy were tested in the stoker. The price of the pellets seemed to be a little high 400 FIM/500 kg large sack. If the sack is returned in good condition 50 FIM deposit will be repaid to the customer. However, Vapo Oy informed that the calorific value of wood pellets is three times higher than that of sod peat so it should not be more expensive than sod peat. When testing the wood pellets in the stoker, the silo of the stoker was filled with wood pellets. The adjustments were first left to position used for sod peat. However, after the fire had ignited well, the adjustments had to be decreased. The content of the silo was combusted totally. The combustion of the content of the 400 litter silo took 4 days and 22 hours. Respectively combustion of 400 l silo of good quality sod peat took 2 days. The water temperature with wood pellets remained at 80 deg C, while with sod peat it dropped to 70 deg C. The main disadvantage of peat with small loads is the unhomogenous composition of the peat. The results of this test showed that wood pellets will give better efficiency than peat, especially when using small burner heads. The utilization of them is easier, and the amount of ash formed in combustion is significantly smaller than with peat. Wood pellets are always homogenous and dry if you do not spoil it with unproper storage. Pellets do not require large storages, the storage volume needed being less than a half of the volume needed for sod peat. When using large sacks the amount needed can even be transported at the trunk of a passenger car. Depending on the area to be heated, a large sack is sufficient for heating for 2-3 weeks. Filling of stoker every 2-5 day is not an enormous task

  14. 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...

  15. 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…

  16. Composite structure of wood cells in petrified wood

    International Nuclear Information System (INIS)

    Nowak, Jakub; Florek, Marek; Kwiatek, Wojciech; Lekki, Janusz; Chevallier, Pierre; Zieba, Emil; Mestres, Narcis; Dutkiewicz, E.M.; Kuczumow, Andrzej

    2005-01-01

    Special kinds of petrified wood of complex structure were investigated. All the samples were composed of at least two different inorganic substances. The original cell structure was preserved in each case. The remnants of the original biological material were detected in some locations, especially in the cell walls. The complex inorganic structure was superimposed on the remnant organic network. The first inorganic component was located in the lumena (l.) of the cells while another one in the walls (w.) of the cells. The investigated arrangements were as follows: calcite (l.)-goethite-hematite (w.)-wood from Dunarobba, Italy; pyrite (l.)-calcite (w.)-wood from Lukow, Poland; goethite (l.)-silica (w.)-wood from Kwaczala, Poland. The inorganic composition was analysed and spatially located by the use of three spectral methods: electron microprobe, X-ray synchrotron-based microprobe, μ-PIXE microprobe. The accurate mappings presenting 2D distribution of the chemical species were presented for each case. Trace elements were detected and correlated with the distribution of the main elements. In addition, the identification of phases was done by the use of μ-Raman and μ-XRD techniques for selected and representative points. The possible mechanisms of the described arrangements are considered. The potential synthesis of similar structures and their possible applications are suggested

  17. Composite structure of wood cells in petrified wood

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Jakub [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Florek, Marek [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Kwiatek, Wojciech [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Lekki, Janusz [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Chevallier, Pierre [LPS, CEN Saclay et LURE, Universite Paris-Sud, Bat 209D, F-91405 Orsay (France); Zieba, Emil [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Mestres, Narcis [Institut de Ciencia de Materials de Barcelona (ICMAB), Campus de la UAB, E-08193-Bellaterra (Spain); Dutkiewicz, E.M. [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Kuczumow, Andrzej [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland)

    2005-04-28

    Special kinds of petrified wood of complex structure were investigated. All the samples were composed of at least two different inorganic substances. The original cell structure was preserved in each case. The remnants of the original biological material were detected in some locations, especially in the cell walls. The complex inorganic structure was superimposed on the remnant organic network. The first inorganic component was located in the lumena (l.) of the cells while another one in the walls (w.) of the cells. The investigated arrangements were as follows: calcite (l.)-goethite-hematite (w.)-wood from Dunarobba, Italy; pyrite (l.)-calcite (w.)-wood from Lukow, Poland; goethite (l.)-silica (w.)-wood from Kwaczala, Poland. The inorganic composition was analysed and spatially located by the use of three spectral methods: electron microprobe, X-ray synchrotron-based microprobe, {mu}-PIXE microprobe. The accurate mappings presenting 2D distribution of the chemical species were presented for each case. Trace elements were detected and correlated with the distribution of the main elements. In addition, the identification of phases was done by the use of {mu}-Raman and {mu}-XRD techniques for selected and representative points. The possible mechanisms of the described arrangements are considered. The potential synthesis of similar structures and their possible applications are suggested.

  18. Statistical black-hole thermodynamics

    International Nuclear Information System (INIS)

    Bekenstein, J.D.

    1975-01-01

    Traditional methods from statistical thermodynamics, with appropriate modifications, are used to study several problems in black-hole thermodynamics. Jaynes's maximum-uncertainty method for computing probabilities is used to show that the earlier-formulated generalized second law is respected in statistically averaged form in the process of spontaneous radiation by a Kerr black hole discovered by Hawking, and also in the case of a Schwarzschild hole immersed in a bath of black-body radiation, however cold. The generalized second law is used to motivate a maximum-entropy principle for determining the equilibrium probability distribution for a system containing a black hole. As an application we derive the distribution for the radiation in equilibrium with a Kerr hole (it is found to agree with what would be expected from Hawking's results) and the form of the associated distribution among Kerr black-hole solution states of definite mass. The same results are shown to follow from a statistical interpretation of the concept of black-hole entropy as the natural logarithm of the number of possible interior configurations that are compatible with the given exterior black-hole state. We also formulate a Jaynes-type maximum-uncertainty principle for black holes, and apply it to obtain the probability distribution among Kerr solution states for an isolated radiating Kerr hole

  19. Selected mechanical properties of modified beech wood

    Directory of Open Access Journals (Sweden)

    Jiří Holan

    2008-01-01

    Full Text Available This thesis deals with an examination of mechanical properties of ammonia treated beach wood with a trademark Lignamon. For determination mechanical properties were used procedures especially based on ČSN. From the results is noticeable increased density of wood by 22% in comparison with untreated beach wood, which makes considerable increase of the most mechanical wood properties. Considering failure strength was raised by 32% and modulus of elasticity was raised at average about 46%.

  20. Harvesting options of small-diameter wood from early thinnings

    Energy Technology Data Exchange (ETDEWEB)

    Kaerhae, K.; Petty, A. (Metsaeteho Oy, Helsinki (Finland)), e-mail: kalle.karha@metsateho.fi; Mutikainen, A. (TTS Research, Rajamaeki (Finland)), e-mail: arto.mutikainen@tts.fi

    2010-07-01

    The integrated harvesting of industrial roundwood and energy wood by the so-called 'two-pile cutting method' has increased steadily in young forests in Finland during the last three years. The studies carried out by Metsaeteho Oy and TTS Research (i) determined the time consumption and productivity in cutting work when using the integrated cutting of first-thinning wood, (ii) clarified the development of the total removal in integrated harvesting operation, and (iii) investigated the quality of pulpwood poles when using integrated cutting with multi-tree handling. The studies indicated that the total removal in integrated wood harvesting increase significantly compared to that of conventional, separate roundwood harvesting. When the total removal from the harvesting site increased considerable, there was a significant increase in the productivity of cutting work in integrated wood harvesting compared to the situation in separate pulpwood harvesting. In addition, the delimbing quality and bucking accuracy of the pulpwood poles obtained in multi-tree processing were comparable to those produced in single-tree handling. There were no problems with measuring the work output by a weight scale attached to the crane of the forwarder. As the studies indicated very promising results with integrated wood cutting, integrated harvesting is likely to continue to increase in both first and later thinnings in Finland. (orig.)

  1. Formation of dioxins and furans during combustion of treated wood

    Energy Technology Data Exchange (ETDEWEB)

    Tame, Nigel W.; Dlugogorski, Bogdan Z.; Kennedy, Eric M. [Process Safety and Environment Protection Research Group, School of Engineering, The University of Newcastle, Callaghan, NSW 2308 (Australia)

    2007-08-15

    Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F, dioxin) are produced in combustion of wood treated with copper-based preservatives. This review summarises and analyses the pertinent literature on the role of preservatives in the formation of dioxin in the low-temperature, vitiated environment that exists in the domestic combustion of wood, and in large-scale fires. Until recently, the role of preservatives was not thoroughly examined in the literature with respect to fires, as incineration attracted most of the research focus. However, latest studies have demonstrated that some current and emerging wood preservatives significantly increase dioxin formation during combustion in domestic stoves and in fires. The following pathways are identified: (i) copper, a common biocide that is chemically bound to the wood, is an important dioxin catalyst, (ii) preservative metals promote smouldering of wood char following cessation of flaming, providing the required temperature environment for dioxin formation, and (iii) chlorinated organics added as secondary preservative components yield dioxin precursors upon thermal decomposition. These conclusions indicate that it remains hazardous to dispose of preservative impregnated timber via domestic combustion even if arsenic is not present. (author)

  2. Manufacture of wood/plastic composites by radiation

    International Nuclear Information System (INIS)

    Iwamoto, Takeo

    1976-01-01

    The manufacture and use of wood/plastic composite (WPC) as an example of wood matrix and wood sawdust/plastic composites (SDP) as an example of plastic matrix are reviewed. The raw material for WPC are mostly vinyl monomers, particularly methyl methacrylate and styrene. The reaction in WPC polymerization is radical polymerization. Researches on the radiation sources mostly resulted in gamma-ray. Electron beam can be applied only to thin products. The future use of WPC may be for furnitures, sporting goods, decorative parts and the like. Vital study on the reduction of manufacturing costs is required, for example, the improvement of reaction and the adoption of continuous process must be considered. The raw materials for SDP are wood sawdust, vinyl monomer (mostly methyl methacrylate) and resins. Electron beam accelerators are the most preferable radiation source because of its high efficiency and safe operation. SDP shows good forming property. The most preferable use of SDP is as interior materials for prefabricated houses, for example, opening frames for bath rooms. Some combination of the technologies of wood engineering, chemical engineering and radiation engineering must be established to develop and maintain the demands. The present radiation sources are forced to grow to large scale industrially, but the establishment of radiation source technology which can be enlarged stepwise is important to keep pace with the development. (Iwakiri, K.)

  3. Analysis of Co-Authorship Indicators, Betweenness Centrality and Structural Holes of the Iranian Nanotechnology Researchers in Science Citation Index (1991-2011

    Directory of Open Access Journals (Sweden)

    Mohammad Hassanzadeh

    2012-12-01

    Full Text Available This research aimed to investigate Iranian papers on nanotechnology area against some scientometrics indicators such as most prolific, most cited and so on. The statistical population were all papers have been published by Iranian researchers on nanotechnology in the Science Citation Index (SCI from 1991 to 7 August 2011 (4605 records that has been done with the aim of identifying, the most prolific, most cited and most effect of Iranian nanotechnology scientists. The results showed that the collaborative index in per-document was 3.39. The highest collaborative index was in 1997 with six authors by per-document. Iranian nanotechnology researchers' degree of collaboration was 0.96 this indicates, greater tendency of nanotechnology authors towards co-authorship. Considering total collaboration coefficient (0.64, nanotechnology authors have shown tendency to production of scientific collaborative document. The highest collaboration coefficient (0.83 And the lowest collaboration coefficient (0.5 have been allocated to the 1997 and 1991 respectively.

  4. Experimental Evaluation of Backfill in Scour Holes Around Offshore Monopiles

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal; Ibsen, Lars Bo; Frigaard, Peter

    2010-01-01

    be to allow the forming of a scour hole and hereby design the monopile with a larger penetration depth. The depth of the scour hole will change over time as the scour depth will increasewhen currents are dominating and backfilling of the scour hole will take placewhenwaves are dominating. Several researchers...... of the foundation for fatigue. A backfill test has been performed in the LargeWave Channel (GWK) of the Coastal Research Centre (FZK) in Hannover.The relative density of the backfilled soil material has based on soil samples and CPT measurements been determined to be in the range of 60–80%. The normalized time...

  5. Black Hole Area Quantization rule from Black Hole Mass Fluctuations

    OpenAIRE

    Schiffer, Marcelo

    2016-01-01

    We calculate the black hole mass distribution function that follows from the random emission of quanta by Hawking radiation and with this function we calculate the black hole mass fluctuation. From a complete different perspective we regard the black hole as quantum mechanical system with a quantized event horizon area and transition probabilities among the various energy levels and then calculate the mass dispersion. It turns out that there is a perfect agreement between the statistical and ...

  6. MICROSTRUCTURE MODIFICATIONS INDUCED IN SPRUCE WOOD BY FREEZING

    Directory of Open Access Journals (Sweden)

    Maria Bernadett SZMUTKU

    2011-12-01

    Full Text Available Scanning Electron Microscopy (SEM is amodern, non-invasive method for objective andspecialized image analysis of anatomical materialfeatures at microscopic level. Referring to wood, itoffers the possibility to view in 3D a bunch ofneighboring cells, in all three grain directions.This allows the imaging of modifications thatmight appear in the structure of the wood cellmembrane (e.g. micro-fissures caused by differentfactors, including temperature variations. This paperpresents the results of the SEM analysis performedon European spruce (Picea abies samples, cut fromboards which were subjected to freezing and thawingunder different conditions of temperature variationand time of exposure.The main aim of this research was to reveal theconditions which determine the occurrence of microfissuresin the cell wall and consequently lead tostrength losses in wood.

  7. 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....

  8. 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...

  9. 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.

  10. 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...

  11. Advances and challenges of wood polymer composites

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

    Wood flour and fiber have been blended with thermoplastic such as polyethylene, polypropylene, polylactic acid and polyvinyl chloride to form wood plastic composites (WPC). WPCs have seen a large growth in the United States in recent years mainly in the residential decking market with the removal of CCA treated wood decking from residential markets. While there are...

  12. The extractives of Pinus pinaster wood

    Science.gov (United States)

    Richard W. Hemingway; W. E. Hillis; L. S. Lau

    1973-01-01

    The extractives in Pinus pinaster wood grown in South Australia were examined as part of an assessment of the suitability of this wood for manufacture of absorbent tissues from bisulphite pulps. The average petroleum solubility of the wood was 2.0% but the amount and composition of the petroleum extract varied widely depending upon the age of the...

  13. 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

  14. 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.

  15. 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.

  16. 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...

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

    African Journals Online (AJOL)

    User

    2011-04-19

    Apr 19, 2011 ... be waste product from saw mills, wood working plants or produced from selected dry wood by .... Stop watch-used to indicate the exact time the mould has remained in the press before wood .... There is abundance of saw dust the source of which is the ... Madison, Wisconsin: Wiley Interscience. Usoro, H. S. ...

  18. Species selection in secondary wood products: perspectives from different consumers

    Science.gov (United States)

    Scott A. Bowe; Matthew S. Bumgardner; Matthew S. Bumgardner

    2004-01-01

    This study investigated adult consumer perceptions of several wood species to determine if word-based and appearance-based evaluations differed. The research replicated a 2001 study by the authors, which used undergraduate college students as a proxy for older and more experienced adult furniture consumers. The literature is somewhat inconclusive concerning the extent...

  19. Experimental design of natural and accellerated bone and wood ageing

    DEFF Research Database (Denmark)

    Facorellis, Y.; Pournou, A.; Richter, Jane

    2015-01-01

    This paper presents the experimental design for natural and accelerated ageing of bone and wood samples found in museum conditions that was conceived as part of the INVENVORG (Thales Research Funding Program – NRSF) investigating the effects of the environmental factors on natural organic materials....

  20. Abnormal compression wood in Pinus taeda : a review of current ...

    African Journals Online (AJOL)

    Abnormal compression wood in P. taeda stands was first discovered in the early 1980s. Since then several research projects and surveys have been carried out in order to develop a better understanding of the problem and to try to find a solution. Currently a large proportion of the sawmill intake of logs in the Mpumalanga ...

  1. Solid-wood production from temperate eucalypt plantations: a ...

    African Journals Online (AJOL)

    Since 1988, there has been a major focus in Tasmania on research for the management of temperate eucalypt plantations for solid wood. This coincided with the formal transfer of large areas of native forest that had previously been part of the production forest estate into reserves, a decision that triggered the establishment ...

  2. A Documentation of Some Traditional Aspects of Wood Consumption in Anaocha, Nigeria

    Directory of Open Access Journals (Sweden)

    Emeka E. Okonkwo

    2016-05-01

    Full Text Available The usefulness of wood to mankind varies from place to place, community to community, state to state, and nation to nation. Wood is a natural product, which is one of the components of biodiversity and a bio-product that serves numerous purposes to mankind. Such multifunctional purposes include those of sociopolitical, economic, religious, and cultural aspects of man. This article examines some traditional aspects of wood consumption in Anaocha Local Government Area of Anambra State, Nigeria, with a view to ascertaining the uses to which the people put wood as a by-product of the trees around them. In-depth interview, on-the-site observation, and focused group discussion were used to elicit information from knowledgeable elders, artisans, and wood vendors in different towns that make up the local government area. This research brings to limelight aspects of wood consumption in Anaocha and lends credence to the belief that wood is still the major source of revenue and energy in rural areas, probably because it is a free gift of nature. The research findings show that modernization has not completely eroded the value of wood in the study area.

  3. Os buracos da lousa: reflexões sobre um tema de pesquisa The holes in the chalkboard: reflections on a research topic

    Directory of Open Access Journals (Sweden)

    Silvia Elizabeth Moraes

    2006-12-01

    Full Text Available Este artigo examina a validade, relevância e exeqüibilidade de um tema de Trabalho de Conclusão de Curso de Licenciatura em Pedagogia. Discute quais critérios podem ser utilizados pelos professores-orientadores no julgamento de um tema de pesquisa para analisar caminhos e resultados esperados em monografias, dissertações e teses em geral. Salienta o processo de construção de um saber teórico-prático tanto por parte do aluno quanto por parte do professor-orientador. Vale-se de um estudo de caso, recorrendo à coleta de dados feita através da análise documental, observação participante, entrevista gravada e conversas telefônicas. Conclui que na pesquisa em educação é necessário formular perguntas simples que tenham a capacidade de relacionar o micro com o macro, o individual com o coletivo, o tópico com o tema, a ciência com a vida.This article analyses the validity, relevance and feasibility of an undergraduate research topic in Education. It starts with a question - which criteria can we, advisors, use in judging a good research theme - in order to analyze ways and results expected in graduate and post-graduate thesis and dissertations. It emphasizes the process of constructing a theoretical-practical knowledge as much as for the student and the teacher-advisor. A case study approach is adopted and the data were collected through documental analysis, participant observation, recorded interview and telephone conversations. The conclusion is that in educational research it is necessary to formulate simple questions that are capable of relating the micro with the macro, the individual with the collective, the topic with the theme, science with life.

  4. 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.

  5. Artificial black holes

    CERN Document Server

    Visser, Matt; Volovik, Grigory E

    2009-01-01

    Physicists are pondering on the possibility of simulating black holes in the laboratory by means of various "analog models". These analog models, typically based on condensed matter physics, can be used to help us understand general relativity (Einstein's gravity); conversely, abstract techniques developed in general relativity can sometimes be used to help us understand certain aspects of condensed matter physics. This book contains 13 chapters - written by experts in general relativity, particle physics, and condensed matter physics - that explore various aspects of this two-way traffic.

  6. The Antarctic ozone hole

    International Nuclear Information System (INIS)

    Jones, Anna E

    2008-01-01

    Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For the historical perspective, the events leading up to the discovery of the 'hole' are presented, as well as the response from the international community and the measures taken to protect the ozone layer now and into the future

  7. Thermal BEC Black Holes

    Directory of Open Access Journals (Sweden)

    Roberto Casadio

    2015-10-01

    Full Text Available We review some features of Bose–Einstein condensate (BEC models of black holes obtained by means of the horizon wave function formalism. We consider the Klein–Gordon equation for a toy graviton field coupled to a static matter current in a spherically-symmetric setup. The classical field reproduces the Newtonian potential generated by the matter source, while the corresponding quantum state is given by a coherent superposition of scalar modes with a continuous occupation number. An attractive self-interaction is needed for bound states to form, the case in which one finds that (approximately one mode is allowed, and the system of N bosons can be self-confined in a volume of the size of the Schwarzschild radius. The horizon wave function formalism is then used to show that the radius of such a system corresponds to a proper horizon. The uncertainty in the size of the horizon is related to the typical energy of Hawking modes: it decreases with the increasing of the black hole mass (larger number of gravitons, resulting in agreement with the semiclassical calculations and which does not hold for a single very massive particle. The spectrum of these systems has two components: a discrete ground state of energy m (the bosons forming the black hole and a continuous spectrum with energy ω > m (representing the Hawking radiation and modeled with a Planckian distribution at the expected Hawking temperature. Assuming the main effect of the internal scatterings is the Hawking radiation, the N-particle state can be collectively described by a single-particle wave-function given by a superposition of a total ground state with energy M = Nm and Entropy 2015, 17 6894 a Planckian distribution for E > M at the same Hawking temperature. This can be used to compute the partition function and to find the usual area law for the entropy, with a logarithmic correction related to the Hawking component. The backreaction of modes with ω > m is also shown to reduce

  8. Quantum effects in black holes

    International Nuclear Information System (INIS)

    Frolov, V.P.

    1979-01-01

    A strict definition of black holes is presented and some properties with regard to their mass are enumerated. The Hawking quantum effect - the effect of vacuum instability in the black hole gravitational field, as a result of shich the black hole radiates as a heated body is analyzed. It is shown that in order to obtain results on the black hole radiation it is sufficient to predetermine the in-vacuum state at a time moment in the past, when the collapsing body has a large size, and its gravitational field can be neglected. The causes and the place of particle production by the black hole, and also the space-time inside the black hole, are considered

  9. Particle creation by black holes

    International Nuclear Information System (INIS)

    Hawking, S.W.

    1975-01-01

    In the classical theory black holes can only absorb and not emit particles. However it is shown that quantum mechanical effects cause black holes to create and emit particles. This thermal emission leads to a slow decrease in the mass of the black hole and to its eventual disappearance: any primordial black hole of mass less than about 10 15 g would have evaporated by now. Although these quantum effects violate the classical law that the area of the event horizon of a black hole cannot decrease, there remains a Generalized Second Law: S + 1/4 A never decreases where S is the entropy of matter outside black holes and A is the sum of the surface areas of the event horizons. This shows that gravitational collapse converts the baryons and leptons in the collapsing body into entropy. It is tempting to speculate that this might be the reason why the Universe contains so much entropy per baryon. (orig.) [de

  10. Black Hole's 1/N Hair

    CERN Document Server

    Dvali, Gia

    2013-01-01

    According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

  11. Pelly Crossing wood chip boiler

    Energy Technology Data Exchange (ETDEWEB)

    1985-03-11

    The Pelly wood chip project has demonstrated that wood chips are a successful fuel for space and domestic water heating in a northern climate. Pelly Crossing was chosen as a demonstration site for the following reasons: its extreme temperatures, an abundant local supply of resource material, the high cost of fuel oil heating and a lack of local employment. The major obstacle to the smooth operation of the boiler system was the poor quality of the chip supply. The production of poor quality chips has been caused by inadequate operation and maintenance of the chipper. Dull knives and faulty anvil adjustments produced chips and splinters far in excess of the one centimetre size specified for the system's design. Unanticipated complications have caused costs of the system to be higher than expected by approximately $15,000. The actual cost of the project was approximately $165,000. The first year of the system's operation was expected to accrue $11,600 in heating cost savings. This estimate was impossible to confirm given the system's irregular operation and incremental costs. Consistent operation of the system for a period of at least one year plus the installation of monitoring devices will allow the cost effectiveness to be calculated. The wood chip system's impact on the environment was estimated to be minimal. Wood chip burning was considered cleaner and safer than cordwood burning. 9 refs., 6 figs., 6 tabs.

  12. 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.)

  13. 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,...

  14. Detecting decay in wood components

    Science.gov (United States)

    R.J. Ross; X. Wang; B.K. Brashaw

    2005-01-01

    This chapter presents a summary of the Wood and Timber Condition Assessment Manual. It focuses on current inspection techniques for decay detection and provides guidelines on the use of various non-destructive evaluation (NDE) methods in locating and defining areas of deterioration in timber bridge components and other civil structures.

  15. Reinvestigation of moving punctured black holes with a new code

    International Nuclear Information System (INIS)

    Cao Zhoujian; Yo Hweijang; Yu Juiping

    2008-01-01

    We report on our code, in which the moving puncture method is applied and an adaptive/fixed mesh refinement is implemented, and on its preliminary performance on black hole simulations. Based on the Baumgarte-Sharpiro-Shibata-Nakamura (BSSN) formulation, up-to-date gauge conditions and the modifications of the formulation are also implemented and tested. In this work, we present our primary results about the simulation of a single static black hole, of a moving single black hole, and of the head-on collision of a binary black hole system. For the static punctured black hole simulations, different modifications of the BSSN formulation are applied. It is demonstrated that both the currently used sets of modifications lead to a stable evolution. For cases of a moving punctured black hole with or without spin, we search for viable gauge conditions and study the effect of spin on the black hole evolution. Our results confirm previous results obtained by other research groups. In addition, we find a new gauge condition, which has not yet been adopted by any other researchers, which can also give stable and accurate black hole evolution calculations. We examine the performance of the code for the head-on collision of a binary black hole system, and the agreement of the gravitational waveform it produces with that obtained in other works. In order to understand qualitatively the influence of matter on the binary black hole collisions, we also investigate the same head-on collision scenarios but perturbed by a scalar field. The numerical simulations performed with this code not only give stable and accurate results that are consistent with the works by other numerical relativity groups, but also lead to the discovery of a new viable gauge condition, as well as clarify some ambiguities in the modification of the BSSN formulation. These results demonstrate that this code is reliable and ready to be used in the study of more realistic astrophysical scenarios and of numerical

  16. What is a black hole

    International Nuclear Information System (INIS)

    Tipler, F.J.

    1979-01-01

    A definition of a black hole is proposed that should work in any stably causal space-time. This is that a black hole is the closure of the smaller future set that contains all noncosmological trapped surfaces and which has its boundary generated by null geodesic segments that are boundary generators of TIPs. This allows precise definitions of cosmic censorship and white holes. (UK)

  17. Black Holes in Higher Dimensions

    Directory of Open Access Journals (Sweden)

    Reall Harvey S.

    2008-09-01

    Full Text Available We review black-hole solutions of higher-dimensional vacuum gravity and higher-dimensional supergravity theories. The discussion of vacuum gravity is pedagogical, with detailed reviews of Myers–Perry solutions, black rings, and solution-generating techniques. We discuss black-hole solutions of maximal supergravity theories, including black holes in anti-de Sitter space. General results and open problems are discussed throughout.

  18. Online sorting of recovered wood waste by automated XRF-technology: part II. Sorting efficiencies.

    Science.gov (United States)

    Hasan, A Rasem; Solo-Gabriele, Helena; Townsend, Timothy

    2011-04-01

    Sorting of waste wood is an important process practiced at recycling facilities in order to detect and divert contaminants from recycled wood products. Contaminants of concern include arsenic, chromium and copper found in chemically preserved wood. The objective of this research was to evaluate the sorting efficiencies of both treated and untreated parts of the wood waste stream, and metal (As, Cr and Cu) mass recoveries by the use of automated X-ray fluorescence (XRF) systems. A full-scale system was used for experimentation. This unit consisted of an XRF-detection chamber mounted on the top of a conveyor and a pneumatic slide-way diverter which sorted wood into presumed treated and presumed untreated piles. A randomized block design was used to evaluate the operational conveyance parameters of the system, including wood feed rate and conveyor belt speed. Results indicated that online sorting efficiencies of waste wood by XRF technology were high based on number and weight of pieces (70-87% and 75-92% for treated wood and 66-97% and 68-96% for untreated wood, respectively). These sorting efficiencies achieved mass recovery for metals of 81-99% for As, 75-95% for Cu and 82-99% of Cr. The incorrect sorting of wood was attributed almost equally to deficiencies in the detection and conveyance/diversion systems. Even with its deficiencies, the system was capable of producing a recyclable portion that met residential soil quality levels established for Florida, for an infeed that contained 5% of treated wood. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Wood Chemical Composition in Species of Cactaceae: The Relationship between Lignification and Stem Morphology

    Science.gov (United States)

    Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos

    2015-01-01

    In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level. PMID:25880223

  20. Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

    Directory of Open Access Journals (Sweden)

    Jorge Reyes-Rivera

    Full Text Available In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35% of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.