WorldWideScience

Sample records for residential wood structures

  1. Discover the benefits of residential wood heating

    International Nuclear Information System (INIS)

    2003-01-01

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

  2. Engineering economic assessment of residential wood heating in NY

    Science.gov (United States)

    We provide insight into the recent resurgence in residential wood heating in New York by: (i) examining the lifetime costs of outdoor wood hydronic heaters (OWHHs) and other whole-house residential wood heat devices,(ii) comparing these lifetime costs with those of competing tech...

  3. Particulate emissions from residential wood combustion

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo; Jensen, Ole Michael; Tarelho, Luis A. C.

    Residential wood combustion (RWC) in fireplaces and conventional appliances is the main contributor to fine particulate matter (PM2.5) emissions in Denmark and Portugal representing more than 30% of the total emissions [1;2]. Such estimations are uncertain concerning the wood consumption...... and official emission factors, not taking into account actual burning conditions in dwellings [3]. There is limited knowledge on the real-life performance and spatial distribution of existing appliance types. Few studies have been targeting to understand the influence of fuel operation habits on PM2...... the available estimations for Denmark and Portugal, suggesting a methodology to increase the accuracy of activity data and emission factors. This work is based on new studies carried out to quantify the PM2.5 emissions in daily life through field experiments in Danish dwellings and by considering typical...

  4. Structural condition assessment of in-service wood

    Science.gov (United States)

    Robert J. Ross; Brian K. Brashaw; Xiping Wang

    2006-01-01

    Wood is used extensively for both interior and exterior applications in the construction of a variety of structures (residential, agricultural, commercial, government, religious). The deterioration of an in-service wood member may result from a variety of causes during the life of a structure. It is important, therefore, to periodically assess the condition of wood...

  5. Wood products and other building materials used in new residential construction in Canada, with comparison to previous studies

    Science.gov (United States)

    Joe Elling; David B. McKeever

    2015-01-01

    New residential construction is a critical driver of the demand for lumber, structural panels and engineered wood products in Canada. For the period 2010 through 2013, residential construction accounted for roughly 23 percent of the lumber consumed in Canada and 47 percent of structural panel usage. Insufficient data concerning imports and exports prevent estimates of...

  6. Challenges in assessing air pollution from residential wood combustion

    DEFF Research Database (Denmark)

    Olesen, Helge Rørdam

    2016-01-01

    The paper highlights a number of important challenges in quantifying the impact of residential wood combustion on air quality. The fact that real life emissions are controlled by the behaviour of the users makes it a challenge to determine representative emission factors. Further, in respect...

  7. RESIDENTIAL WOOD COMBUSTION TECHNOLOGY REVIEW VOLUME 1. TECHNICAL REPORT

    Science.gov (United States)

    This report gives results of a review of the current state-of-the-art of residential wood combustion (RWC). The key environmental parameter of concern was the air emission of particles. The technological status of all major RWC categories -- cordwood stoves, fireplaces, masonry h...

  8. RESIDENTIAL WOOD COMBUSTION TECHNOLOGY REVIEW - VOLUME 2. APPENDICES

    Science.gov (United States)

    The report gives results of a review of the current state-of-the-art of residential wood combustion (RWC). The key environmental parameter of concern was the air emission of particles. The technological status of all major RWC categories--cordwood stoves, fireplaces, masonry heat...

  9. Spatial emission modelling for residential wood combustion in Denmark

    DEFF Research Database (Denmark)

    Plejdrup, Marlene Schmidt; Nielsen, Ole-Kenneth; Brandt, Jørgen

    2016-01-01

    Residential wood combustion (RWC) is a major contributor to atmospheric pollution especially for particulate matter. Air pollution has significant impact on human health, and it is therefore important to know the human exposure. For this purpose, it is necessary with a detailed high resolution sp...

  10. Wood products used for residential repair and remodeling in the United States, 1991

    Science.gov (United States)

    D. B. McKeever; R. G. Anderson

    Large amounts of lumber and wood panel products are used annually for the repair and remodeling of residential structures and properties in the United States. In response to the need by government and industry for detailed information on this important market for timber products, a study was conducted by the Timber Demand and Technology...

  11. Formaldehyde and acetaldehyde emissions from residential wood combustion in Portugal

    Science.gov (United States)

    Cerqueira, Mário; Gomes, Luís; Tarelho, Luís; Pio, Casimiro

    2013-06-01

    A series of experiments were conducted to characterize formaldehyde and acetaldehyde emissions from residential combustion of common wood species growing in Portugal. Five types of wood were investigated: maritime pine (Pinus pinaster), eucalyptus (Eucalyptus globulus), cork oak (Quercus suber), holm oak (Quercus rotundifolia) and pyrenean oak (Quercus pyrenaica). Laboratory experiments were performed with a typical wood stove used for domestic heating in Portugal and operating under realistic home conditions. Aldehydes were sampled from diluted combustion flue gas using silica cartridges coated with 2,4-dinitrophenylhydrazine and analyzed by high performance liquid chromatography with diode array detection. The average formaldehyde to acetaldehyde concentration ratio (molar basis) in the stove flue gas was in the range of 2.1-2.9. Among the tested wood types, pyrenean oak produced the highest emissions for both formaldehyde and acetaldehyde: 1772 ± 649 and 1110 ± 454 mg kg-1 biomass burned (dry basis), respectively. By contrast, maritime pine produced the lowest emissions: 653 ± 151 and 371 ± 162 mg kg-1 biomass (dry basis) burned, respectively. Aldehydes were sampled separately during distinct periods of the holm oak wood combustion cycles. Significant variations in the flue gas concentrations were found, with higher values measured during the devolatilization stage than in the flaming and smoldering stages.

  12. 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...

  13. Effects of topographic position and geology on shaking damage to residential wood-framed structures during the 2003 San Simeon earthquake, western San Luis obispo county, California

    Science.gov (United States)

    McCrink, T.P.; Wills, C.J.; Real, C.R.; Manson, M.W.

    2010-01-01

    A statistical evaluation of shaking damage to wood-framed houses caused by the 2003 M6.5 San Simeon earthquake indicates that both the rate and severity of damage, independent of structure type, are significantly greater on hilltops compared to hill slopes when underlain by Cretaceous or Tertiary sedimentary rocks. This increase in damage is interpreted to be the result of topographic amplification. An increase in the damage rate is found for all structures built on Plio-Pleistocene rocks independent of topographic position, and this is interpreted to be the result of amplified shaking caused by geologic site response. Damage rate and severity to houses built on Tertiary rocks suggest that amplification due to both topographic position and geologic site response may be occurring in these rocks, but effects from other topographic parameters cannot be ruled out. For all geologic and topographic conditions, houses with raised foundations are more frequently damaged than those with slab foundations. However, the severity of damage to houses on raised foundations is only significantly greater for those on hill slopes underlain by Tertiary rocks. Structures with some damage-resistant characteristics experienced greater damage severity on hilltops, suggesting a spectral response to topographic amplification. ?? 2010, Earthquake Engineering Research Institute.

  14. An engineering economic assessment of whole-house residential wood heating in New York

    Science.gov (United States)

    Wood devices are being selected increasingly for residential space heating by households in New York State. Motivations for their use include energy independence, mitigating climate change, stimulating local economic development, and reducing exposure to high and variable fuel c...

  15. Comparison of neighborhood-scale residential wood smoke emissions inventories using limited and intensive survey data

    International Nuclear Information System (INIS)

    Baxter, T.E.

    1998-01-01

    Emission inventory based estimations of pollutants resulting from residential combustion of wood are typically determined by collecting survey data that represent a single but relatively large area. While the pollutants in wood smoke emissions may represent a relatively low fraction (<10%) of an area's total annual emissions mass inventory, they can concentrate within the specific neighborhood areas where emitted. Thus, while the representativeness of a large-area survey approach is valid and useful, its application for estimating wood smoke pollutant levels within any particular neighborhood may be limited. The ability to obtain a better estimation of pollutant levels for evaluating potential health-related impacts within neighborhoods where wood smoke pollutants can concentrate requires survey data more representative of the particular area. This study compares residential wood combustion survey data collected from six residential neighborhoods in the metropolitan area of Flagstaff, Arizona. The primary purpose of this study is to determine the ability of data collected from a limited neighborhood-scale survey effort to represent that neighborhood's wood fuel consumption characteristics and wood smoke emissions. In addition, the variation that occurs between different neighborhoods regarding residential consumption of wood is also evaluated. Residential wood combustion survey data were collected compare wood burning device distribution, wood types and quantities burned, and emission rates. One neighborhood was surveyed once at approximately a 10% distribution rate and again at a 100% distribution rate providing data for evaluating the ability of a limited-effort survey to represent a more intensive survey. Survey methodology, results and recommendations are presented

  16. Wood Products Other Building Materials Used in New Residential Construction in the United States

    Science.gov (United States)

    David B. McKeever; Joe Elling

    2015-01-01

    On average, new residential construction accounts for about one-third of all wood products consumed in the United States annually. During periods of robust housing activity, 45% or more of all wood products consumed are for new single-family and multifamily housing. This can fall to as low as 20% or less during times of economic recession. Unfortunately, 2012 was not...

  17. 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....

  18. Structural Evaluation Procedures for Heavy Wood Truss Structures

    National Research Council Canada - National Science Library

    Issa, Mohsen

    1998-01-01

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

  19. Development of a residential wood smoke reduction plan in a wood burning community: A case study in Libby, Montana

    International Nuclear Information System (INIS)

    Fox, R.J.; Manderino, L.; Lyons, C.E.; Morris, A.L.; Anderson, R.L.

    1992-01-01

    Libby, Montana depends on wood as a heating fuel. Libby exceeded the 24-hour federal PM10 ambient air quality standard every year since monitoring began in 1987. Residential wood smoke significantly contributes to its air pollution. To decrease residential wood smoke's contribution to air pollution, residents have to modify their heating habits. County officials sponsored the development of a comprehensive community-oriented plan to reduce wood smoke. This paper describes how the plan was developed and the components of the air pollution reduction strategies. The plan was developed using community input and tailored to local conditions. Four specific strategies were developed to reduce residential wood smoke pollution. Development of strategies required analysis of home heating habits and potential alternatives. Economic conditions were also considered. Expensive control strategies would be worthless unless alternative funding methods were provided. Thus, the plan included an array of funding sources to facilitate implementation. The development and implementation techniques are applicable to other communities with similar air pollution challenges

  20. A novel field measurement method for determining fine particle and gas emissions from residential wood combustion

    Science.gov (United States)

    Tissari, Jarkko; Hytönen, Kati; Lyyränen, Jussi; Jokiniemi, Jorma

    Emission data from residential wood combustion are usually obtained on test stands in the laboratory but these measurements do not correspond to the operational conditions in the field because of the technological boundary conditions (e.g. testing protocol, environmental and draught conditions). The field measurements take into account the habitual practice of the operators and provide the more reliable results needed for emission inventories. In this study, a workable and compact method for measuring emissions from residential wood combustion in winter conditions was developed. The emissions for fine particle, gaseous and PAH compounds as well as particle composition in real operational conditions were measured from seven different appliances. The measurement technique worked well and was evidently suitable for winter conditions. It was easy and fast to use, and no construction scaffold was needed. The dilution of the sample with the combination of a porous tube diluter and an ejector diluter was well suited to field measurement. The results indicate that the emissions of total volatile organic carbon (TVOC) (17 g kg -1 (of dry wood burned)), carbon monoxide (CO) (120 g kg -1) and fine particle mass (PM 1) (2.7 g kg -1) from the sauna stove were higher than in the other measured appliances. In the masonry heaters, baking oven and stove, the emissions were 2.9-9 g kg -1 TVOC, 28-68 g kg -1 CO and 0.6-1.6 g kg -1 PM 1. The emission of 12 PAHs (PAH 12) from the sauna stove was 164 mg kg -1 and consisted mainly of PAHs with four benzene rings in their structure. PAH 12 emission from other appliances was, on average, 21 mg kg -1 and was dominated by 2-ring PAHs. These results indicate that despite the non-optimal operational practices in the field, the emissions did not differ markedly from the laboratory measurements.

  1. Preliminary correlation of organic molecular tracers in residential wood smoke with the source of fuel

    Science.gov (United States)

    Standley, Laurel J.; Simoneit, Bernd R. T.

    Polar cyclic di- and triterpenoids were analyzed in the extracts of residential wood combustion aerosols collected in suburban sections of Eugene, Oakridge and Corvallis, Oregon. Additional samples collected included alder wood, smoke from two wood stoves burning only alder or pine as fuel, soot from a stove burning alder and a fireplace where oak was the predominant fuel. Due to the relatively cooler temperatures present under the smoldering conditions of residential wood combustion, as compared to the active burning of forest fires and slash burns, incomplete combustion resulted in the preservation of high levels of the natural products. There were three distinct signatures which could be used to trace relative input from coniferous, alder and oak combustion products, i.e. diterpenoids, lupane-derived triterpenoids and friedelin, respectively. Conifer combustion products dominated the suburban smoke aerosols.

  2. Residential wood heating: The forest, the atmosphere and the public consciousness

    International Nuclear Information System (INIS)

    Gulland, J.F.; Hendrickson, O.Q.

    1993-01-01

    It is generally agreed by both energy and forestry scientists that, provided harvesting is conducted in a sustainable manner, the combustion of wood for energy production is essentially carbon dioxide neutral when the normal forest regeneration period is considered. When wood combustion replaces the consumption of fossil fuels, however, the net reduction in carbon dioxide release is almost immediate. In addition to the requirement of sustainable forestry practices, the maintenance of site biodiversity must also be considered. A preliminary review of the literature reveals that periodic selective harvesting can actually have a positive impact on the biodiversity of the forest. Despite the fact that the harvesting, processing and transportation of wood fuel invariably consumes fossil fuels, it has been shown in case studies that the energy return on investment can easily exceed a ratio of 25:1. Approximately 20 percent of the single family dwellings in Canada are heated to some extent with wood and the potential exists for an increasing contribution of wood fuel to residential energy requirements. However, there is evidence of confusion among the public regarding the environmental impact of woodburning, particularly as it relates to CO 2 emissions and carbon storage in forests. The confusion could impede the increased use of wood for residential heating because it calls into question the appropriateness of using wood for energy purposes. The forms of residential wood energy use that have evolved in rural North America provide important but neglected models of sustainable development. This could serve as the central theme of public information program to clarify the role of wood energy in the reduction of greenhouse gas emissions

  3. A refinement of the potassium tracer method for residential wood smoke

    Science.gov (United States)

    Calloway, C. P.; Li, S.; Buchanan, J. W.; Stevens, R. K.

    Potassium has been used as a tracer for the mass of fine particles emitted to the air from residential wood burning stoves and fireplaces. The technique involves measurement by x-ray fluorescence of the total K collected on fine particle filters. Since wind blown soil particles also contain K, a correction for this contribution is made based upon soil analysis or an assumed K/Fe ratio in local soil. K in excess of this ratio is considered to be from wood smoke. The purpose of this study is to demonstrate an alternative method for determining wood smoke K. The underlying assumption is that wood smoke K is water soluble but that K in crustal particles is in a mineralized form and only slightly water soluble. Results from analyses of particle samples indicate the two methods yield essentially the same amount of wood smoke K.

  4. Wood energy for residential heating in Alaska: current conditions, attitudes, and expected use

    Science.gov (United States)

    David L. Nicholls; Allen M. Brackley; Valerie. Barber

    2010-01-01

    This study considered three aspects of residential wood energy use in Alaska: current conditions and fuel consumption, knowledge and attitudes, and future use and conditions. We found that heating oil was the primary fuel for home heating in southeast and interior Alaska, whereas natural gas was used most often in south-central Alaska (Anchorage). Firewood heating...

  5. Chapter 6: Fire damage of wood structures

    Science.gov (United States)

    B. Kukay; R.H. White; F. Woeste

    2012-01-01

    Depending on the severity, fire damage can compromise the structural integrity of wood structures such as buildings or residences. Fire damage of wood structures can incorporate several models that address (1) the type, cause, and spread of the fire, (2) the thermal gradients and fire-resistance ratings, and (3) the residual load capacity (Figure 6.1). If there is a...

  6. Wood pellet use in Sweden. A systems approach to the residential sector

    International Nuclear Information System (INIS)

    Vinterbaeck, Johan

    2000-01-01

    This empirically based thesis deals with a biofuel market in a systems context with focus on Sweden. Fuel pellets is a new consumer market for wood products. Initially used mainly by large-scale heating plants, wood pellets expanded into the Swedish residential heating market in the mid 1990s. The overall aim of this work is to provide a deeper understanding of the system for small-scale use of densified wood fuels. The objective was to provide a mapping and logistic analysis of fuel and delivery chains primarily for wood pellets. The description includes both technical as well as economic and organisational aspects. The thesis in particular investigates (i) experience from practical densification operations in the past, (ii) wood pellet retailers in Sweden, (iii) wood pellet consumers in Austria, Sweden and the United States, (iv) imports of wood pellets, and (v) forecasting of pellet consumption and inventory management for wood pellet distributors. Previous international studies revealed that the availability of cheap raw materials for fuel production and the price and availability of the most important competing fuels: coal, oil and natural gas were important factors that have guided production and use of densified wood and bark fuels. A major network of wood pellet distributors was mapped. It was concluded from a survey to these retailers that the Swedish residential market was now firmly in place and that the price of wood pellets was competitive with prices of traditional national fuels. A majority of pellet users in Austria, Sweden and the United States were pleased with pellet heating. One way to improve pellet distribution systems would be to optimise inventory management. An internal model for optimising inventory management, Pell-Sim, was constructed. For Sweden, wood pellets in 1997 represented the second most traded biofuel assortment, with 4.35 PJ or 18% of the total biofuel imports. Contrary to trade with other biofuel assortments, wood pellet trade

  7. Model development for spatial variation of PM2.5 emissions from residential wood burning

    International Nuclear Information System (INIS)

    Yong Q, Tian; Peng Gong; Qian Yu; Radke, John D.

    2004-01-01

    This paper presents a preliminary research result of spatially quantifying and allocating the potential activity of residential wood burning (RWB) by using demographic, hypsographic, climatic and topographic information as independent variables. We also introduce the method for calculating PM 2.5 emission from residential wood combustion with the potential activity as primary variable. A linear regression model was generated to describe spatial and temporal distribution of the potential activity of wood burning as primary heating source. In order to improve the estimation, the classifications of urban, suburban and rural were redefined to meet the specifications of this application. Also, a unique way of defining forest accessibility is found useful in estimating the activity potential of RWB. The results suggest that the potential activity of wood burning is mostly determined by elevation of a location, forest accessibility, urban/non-urban position, climatic conditions and several demographic variables. The analysis results were validated using survey data collected through face-to-face and telephone interviews over the study area in central California. The linear regression model can explain approximately 86% of the variation of surveyed wood burning activity potential. The total PM 2.5 emitted from woodstoves and fireplaces is analyzed for the study region at county level. (Author)

  8. Particle Emission Characteristics of Modern and Old-Type Residential Boilers Fired with Wood Logs and Wood Pellets

    International Nuclear Information System (INIS)

    Johansson, L.S.; Gustavsson, L.; Tullin, C.; Potter, A.; Leckner, B.

    2005-01-01

    Residential biofuel combustion for heating can be performed in two ways: in a stove heating the surrounding room, or in a boiler heating water to be circulated through a piping system to heat an entire house. In contrast to stoves, wood boilers can be connected to heat storage tanks, which is an advantage from an emission point of view. The present work focuses on comparing emissions from old-type and modern boilers by means of systematic variation of combustion device, fuel quality, firing behaviour, and the influence of heat storage tank. User habits are simulated in a schematic way. The purpose of the comparison is to determine the emission differences between old-type and modern residential biofuel boilers and to quantify emission characteristics of different kind of biofuel combustion

  9. Application and feasibility of coal fly ash and scrap tire fiber as wood wall insulation supplements in residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Van de Lindt, J.W.; Carraro, J.A.H.; Heyliger, P.R.; Choi, C. [Colorado State University, Department of Civil and Environmental Engineering, Fort Collins, CO (United States)

    2008-08-15

    Each year, nearly 55% of the fly ash (FA) produced by coal burning power plants in the United States is disposed of in landfills and ash ponds, while the amount of recycled fiber from scrap tires that is beneficially used in end-user markets is virtually negligible. This paper presents the results of a study carried out to investigate whether it might be possible to increase the thermal efficiency of a light-frame residential structure through addition of a fly ash-scrap tire fiber composite to traditional fiberglass insulation in light-frame wood residential construction. This type of construction represents more than 80% of the building stock in North America. The results of this study suggest that the fly ash-scrap tire fiber composite provides a sustainable supplement to traditional insulation that not only increases the efficiency of traditional insulation but can also help significantly reduce the environmental issues associated with disposal of these waste products. (author)

  10. Application and feasibility of coal fly ash and scrap tire fiber as wood wall insulation supplements in residential buildings

    International Nuclear Information System (INIS)

    Van de Lindt, J.W.; Carraro, J.A.H.; Heyliger, P.R.; Choi, C.

    2008-01-01

    Each year, nearly 55% of the fly ash (FA) produced by coal burning power plants in the United States is disposed of in landfills and ash ponds, while the amount of recycled fiber from scrap tires that is beneficially used in end-user markets is virtually negligible. This paper presents the results of a study carried out to investigate whether it might be possible to increase the thermal efficiency of a light-frame residential structure through addition of a fly ash-scrap tire fiber composite to traditional fiberglass insulation in light-frame wood residential construction. This type of construction represents more than 80% of the building stock in North America. The results of this study suggest that the fly ash-scrap tire fiber composite provides a sustainable supplement to traditional insulation that not only increases the efficiency of traditional insulation but can also help significantly reduce the environmental issues associated with disposal of these waste products. (author)

  11. 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

  12. 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.

  13. Domestic Wood Burning in a Residential Area: PM2.5 Trace Elements and Black Smoke

    International Nuclear Information System (INIS)

    Molnar, P.; Gustafson, P.; Johannesson, S.; Barregaard, L.; Saellsten, G.; Boman, J.

    2005-01-01

    Indoor and outdoor levels of PM2.5 have been studied in a residential area in Hagfors, a small town in Sweden. The sampling took place during typical Swedish winter conditions with sub-zero temperatures and full snow cover between February 10th and Mars 6th, 2003. The area consists of single houses having different heating systems. Some of the houses are heated by burning wood; some use heat pumps while others use direct electrical heating. 13 houses burning wood in boilers or similar for heating and 10 houses heated by other means but situated in the same area were selected for this study. Only houses without tobacco smoke were selected since this is one of the major sources of indoor particles. The objectives of the study were to identify levels and differences in composition of aerosol particles outdoors and inside houses with boilers using wood as fuel and houses heated in other ways. For K, Ca, Mn, Zn and Rb significantly higher (p < 0.05) indoor concentration for wood burners were found. The elements most often referred to as markers for wood burning are K and Zn. In addition, Si, S, Cl, Br and Rb are also mentioned as markers (Hedberg et al., 2002, Moloi et al., 2003). Black smoke was linked to wood burning, although not fully significant (p-value 0.07), as seen in figure 1a. Within the wood-burning group, some houses have concentrations comparable to the concentrations in the houses where no wood is used, while the others have much higher concentrations. These houses also have higher concentrations of K compared to the other wood burners. The possible reasons are different types of wood burning appliances and their placement in the houses as well as possible leakage. Sulphur, although sometimes linked to wood burning, shows no relationship to wood burning in this study. In figure 1b it can be seen that the indoor concentrations of sulphur is clearly lower compared to outdoor concentrations and that the levels indoors do not differ between wood and non-wood

  14. Impact of wood combustion on particle levels in a residential area in Denmark

    DEFF Research Database (Denmark)

    Glasius, M.; Ketzel, M.; Wåhlin, P.

    2006-01-01

    The influence of residential wood-combustion on local air quality was studied during two periods in 2002 and 2003/04 in a small rural town with widespread use of wood combustion for heating. During one 6-week winter period, particle levels (PM2.5) in the residential area were about 4 μg m-3 higher...... than at a nearby background site. This was comparable to the local traffic contribution observed at a busy street (about 70,000 vehicles per day) in the city of Copenhagen. The diurnal variation in the residential area showed increased particle levels (PM2.5) in the evening and night as expected from...... local heating sources. Particle size distributions showed highest volume concentrations of particles with diameters of 400-500 nm, and the diurnal variation of particle volume was similar to PM2.5. The particle measurements were supported by measurements of combustion gases in both the residential area...

  15. VOC emissions from residential combustion of Southern and mid-European woods

    Science.gov (United States)

    Evtyugina, Margarita; Alves, Célia; Calvo, Ana; Nunes, Teresa; Tarelho, Luís; Duarte, Márcio; Prozil, Sónia O.; Evtuguin, Dmitry V.; Pio, Casimiro

    2014-02-01

    Emissions of trace gases (carbon dioxide (CO2), carbon monoxide (CO), total hydrocarbons (THC)), and volatile organic compounds (VOCs) from combustion of European beech, Pyrenean oak and black poplar in a domestic woodstove and fireplace were studied. These woods are widely used as biofuel in residential combustion in Southern and mid-European countries. VOCs in the flue gases were collected in Tedlar bags, concentrated in sorbent tubes and analysed by thermal desorption-gas chromatography-flame ionisation detection (GC-FID). CO2 emissions ranged from 1415 ± 136 to 1879 ± 29 g kg-1 (dry basis). The highest emission factors for CO and THC, 115.8 ± 11.7 and 95.6 24.7 ± 6.3 g kg-1 (dry basis), respectively, were obtained during the combustion of black poplar in the fireplace. European beech presented the lowest CO and THC emission factors for both burning appliances. Significant differences in emissions of VOCs were observed among wood species burnt and combustion devices. In general the highest emission factors were obtained from the combustion of Pyrenean oak in the woodstove. Among the VOCs identified, benzene and related compounds were always the most abundant group, followed by oxygenated compounds and aliphatic hydrocarbons. The amount and the composition of emitted VOCs were strongly affected by the wood composition, the type of burning device and operating conditions. Emission data obtained in this work are useful for modelling the impact of residential wood combustion on air quality and tropospheric ozone formation.

  16. Analytical electron microscopy of combustion particles: a comparison of vehicle exhaust and residential wood smoke

    International Nuclear Information System (INIS)

    Kocbach, A.; Johansen, B.V.; Schwarze, P.E.; Namork, E.

    2005-01-01

    Particulate matter has been associated with a number of adverse health effects. Since combustion particles from vehicle exhaust and wood smoke are common constituents of ambient air, the morphology and elemental composition of particles from these two sources were analysed and compared using single particle analysis. Ambient air particles were collected in locations dominated by vehicle exhaust or residential wood smoke. To verify the source contributions to the ambient air samples, particles were collected directly from the combustion sources. All particulate samples were analysed on carbon extraction replica by transmission electron microscopy (TEM) and X-ray microanalysis (XRMA). The particles were classified into four groups based on morphology and elemental composition. Carbon aggregates were the only particles identified to originate from combustion sources and accounted for more than 88% of the particle numbers in the ambient air samples from both sources. The carbon aggregates were therefore further analysed with respect to morphology and elemental composition on germanium extraction replica. Carbon aggregates from vehicle exhaust were characterised by higher levels of Si and Ca compared to wood smoke aggregates that contained higher levels of K. The S content in aggregates from both sources was probably caused by interaction with gases in the air. Furthermore, the diameters of primary particles from vehicle exhaust were significantly smaller (27±7 nm) than the diameters for wood smoke (38±11 nm). The observed differences in elemental profiles and primary particle diameters for vehicle exhaust and wood smoke may influence the health effects caused by these particles

  17. Residential wood combustion technology review: Volume 1. Final technical report, July 1997--July 1998

    International Nuclear Information System (INIS)

    Houck, J.E.; Tiegs, P.E.

    1998-12-01

    The report gives results of a review of the current state-of-the-art of residential wood combustion (RWC). The key environmental parameter of concern was the air emission of particles. The technological status of all major RWC categories--cordwood stoves, fireplaces, masonry heaters, pettel stoves, and wood-fired central heating furnaces--was reviewed. Advances in technology achieved since the mid-1980s were the primary focus. Key findings of the review included: (1) the new source performance standard (NSPS) certification procedure only qualitatively predicts the level of emissions from wood heaters under actual use in homes; (2) woodstove durability varies with model, and a method to assess the durability problem is controversial; (3) nationally, the overwhelming majority of RWC air emissions are from noncertified devices (primarily from older noncertified woodstoves); (4) new technology appliances and fuels can reduce emissions significantly; (5) the International Organization for Standardization and EPA NSPS test procedures are quite dissimilar, and data generated by the two procedures would not be comparable; and (6) the effect of wood moisture and wood type on particulate emission appears to be real but less than an order of magnitude

  18. Residential wood combustion technology review: Volume 2 -- Appendices. Final report, July 1997--July 1998

    International Nuclear Information System (INIS)

    Houck, J.E.; Tiegs, P.E.

    1998-12-01

    The report gives results of a review of the current state-of-the-art of residential wood combustion (RWC). The key environmental parameter of concern was the air emission of particles. The technological status of all major RWC categories--cordwood stoves, fireplaces, masonry heaters, pettel stoves, and wood-fired central heating furnaces--was reviewed. Advances in technology achieved since the mid-1980s were the primary focus. Key findings of the review included: (1) the new source performance standard (NSPS) certification procedure only qualitatively predicts the level of emissions from wood heaters under actual use in homes; (2) woodstove durability varies with model, and a method to assess the durability problem is controversial; (3) nationally, the overwhelming majority of RWC air emissions are from noncertified devices (primarily from older noncertified woodstoves); (4) new technology appliances and fuels can reduce emissions significantly; (5) the International Organization for Standardization and EPA NSPS test procedures are quite dissimilar, and data generated by the two procedures would not be comparable; and (6) the effect of wood moisture and wood type on particulate emission appears to be real but less than an order of magnitude

  19. European wood pellet market integration - A study of the residential sector

    International Nuclear Information System (INIS)

    Olsson, Olle; Hillring, Bengt; Vinterbaeck, Johan

    2011-01-01

    The integration of European energy markets is a key goal of EU energy policy, and has also been the focal point of many scientific studies in recent years. International markets for coal, oil, natural gas and electricity have previously been investigated in order to determine the extent of the respective markets. This study enhances this field of research to bioenergy markets. Price series data and time series econometrics are used to determine whether residential sector wood pellet markets of Austria, Germany and Sweden are integrated. The results of the econometric tests show that the German and Austrian markets can be considered to be integrated, whereas the Swedish market is separate from the other two countries. Although increased internationalization of wood pellet markets is likely to contribute to European price convergence and market integration, this process is far from completed. (author)

  20. Transparent wood for functional and structural applications

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Yang, Xuan; Berglund, Lars

    2017-12-01

    Optically transparent wood combines mechanical performance with optical functionalities is an emerging candidate for applications in smart buildings and structural optics and photonics. The present review summarizes transparent wood preparation methods, optical and mechanical performance, and functionalization routes, and discusses potential applications. The various challenges are discussed for the purpose of improved performance, scaled-up production and realization of advanced applications. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  1. Chemical speciation of PM2.5 emissions from residential wood combustion and meat cooking

    International Nuclear Information System (INIS)

    McDonald, J.; Zielinska, B.; Fujita, E.; Chow, J.; Watson, J.; Sagebiel, J.; Sheetz, L.; Batie, S.

    1998-01-01

    Residential wood combustion and meat cooking emissions were each analyzed to develop a chemical emissions profile. Samples were collected using a DRI-constructed dilution stack sampler equipped with a 2.5 mm particle selective cyclone. Emissions were diluted 30-100 times, cooled to ambient temperature, and were allowed 80 seconds for condensation prior to collection. Fireplace and wood-stove emissions testing was conducted at the DRI facilities. Wood type, wood moisture, burn rate, and fuel load were varied for different experiments. Meat emissions testing was conducted at the CE-CERT stationary emissions lab in Riverside, California. Meat type, fat content, and the cooking appliance used were changed in different tests. Fine particle and semi-volatile organic compounds were collected on filter/PUF/XAD/PUF cartridges. Inorganic samples were collected on Teflon and quartz filters, which were analyzed for mass by gravimetry, elements by x-ray fluorescence, ammonium by automated colorimetry, organic and elemental carbon by thermal/optical reflectance, as well as chloride, nitrate, and sulfate by ion chromatography. Analysis of organic species was conducted by gas chromatography/mass spectrometry (GC/MS). These data have been utilized for constructing specific profiles for use in the Chemical Mass Balance model for apportionment of fine particle sources in the Denver, Colorado, region

  2. 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...

  3. Family Structure, Residential Mobility, and Environmental Inequality

    Science.gov (United States)

    Downey, Liam; Crowder, Kyle; Kemp, Robert J.

    2016-01-01

    This study combines micro-level data on families with children from the Panel Study of Income Dynamics with neighborhood-level industrial hazard data from the Environmental Protection Agency and neighborhood-level U.S. census data to examine both the association between family structure and residential proximity to neighborhood pollution and the micro-level, residential mobility processes that contribute to differential pollution proximity across family types. Results indicate the existence of significant family structure differences in household proximity to industrial pollution in U.S. metropolitan areas between 1990 and 1999, with single-mother and single-father families experiencing neighborhood pollution levels that are on average 46% and 26% greater, respectively, than those experienced by two-parent families. Moreover, the pollution gap between single-mother and two-parent families persists with controls for household and neighborhood socioeconomic, sociodemographic, and race/ethnic characteristics. Examination of underlying migration patterns reveals that single-mother, single-father, and two-parent families are equally likely to move in response to pollution. However, mobile single-parent families move into neighborhoods with significantly higher pollution levels than do mobile two-parent families. Thus, family structure differences in pollution proximity are maintained more by these destination neighborhood differences than by family structure variations in the likelihood of moving out of polluted neighborhoods. PMID:28348440

  4. The wood pellet market in Austria: A structural market model analysis

    International Nuclear Information System (INIS)

    Kristöfel, Christa; Strasser, Christoph; Schmid, Erwin; Morawetz, Ulrich B.

    2016-01-01

    EU bioenergy policies and oil price hikes have resulted in a significant increase of installed pellet boilers for residential heating. Hence, European demand for wood pellets has been growing faster and more steadily than supply leading to rising market prices in recent years. This article presents an econometric analysis of demand and supply of wood pellets in the residential heating sector in Austria, one of the most dynamic markets for residential pellets. Annual and monthly time series data between 2000 and 2014 are used in a two-stage least-squares (2SLS) regression to estimate supply and demand elasticities of wood pellets. In all model specifications, pellets demand is found to be inelastic (from −0.66 to −0.76) and pellets supply unit-elastic (from 1.03 to 1.18). Thus, consumers are highly exposed to price changes resulting from supply shocks. Policies which support investments in pellet boilers will shift the demand of wood pellets and likely leading to higher prices for consumers. - Highlights: • Characterisation of the European pellet market. • A structural market model for wood pellets in Austria. • Estimation of supply and demand price elasticities using a two-stage least-squares (2SLS) regression. • Pellets demand is found to be inelastic and pellets supply unit-elastic in the short run. • Policies stimulating demand will likely increase pellet and sawmill by-product prices.

  5. Construction Cluster Volume I [Wood Structural Framing].

    Science.gov (United States)

    Pennsylvania State Dept. of Justice, Harrisburg. Bureau of Correction.

    The document is the first of a series, to be integrated with a G.E.D. program, containing instructional materials at the basic skills level for the construction cluster. It focuses on wood structural framing and contains 20 units: (1) occupational information; (2) blueprint reading; (3) using leveling instruments and laying out building lines; (4)…

  6. 2006 : Wood Used in Residential Repair and Remodeling U.S. and Canada, with Comparison to 1997 and 2003 : Executive Summary

    Science.gov (United States)

    Craig Adair; David B. McKeever

    2009-01-01

    The repair and remodeling of residential units in both the United States and Canada is an important market for wood products. Many and varied repair and remodeling activities and projects are undertaken annually. Some require substantial amounts of wood products, some none at all. In 2006, about 28 percent of all solid wood products consumed in the United States and 31...

  7. Source apportionment of PM2.5 at multiple Northwest U.S. sites: Assessing regional winter wood smoke impacts from residential wood combustion

    Science.gov (United States)

    Kotchenruther, Robert A.

    2016-10-01

    Wood smoke from residential wood combustion is a significant source of elevated PM2.5 in many communities across the Northwest U.S. Accurate representation of residential wood combustion in source-oriented regional scale air quality models is challenging because of multiple uncertainties. As an alternative to source-oriented source apportionment, this work provides, through receptor-oriented source apportionment, an assessment of winter residential wood combustion impacts at multiple Northwest U.S. locations. Source apportionment was performed on chemically speciated PM2.5 from 19 monitoring sites using the Positive Matrix Factorization (PMF) receptor model. Each site was modeled independently, but a common data preparation and modeling protocol was used so that results were as comparable as possible across sites. Model solutions had from 4 to 8 PMF factors, depending on the site. PMF factors at each site were associated with a source classification (e.g., primary wood smoke), a dominant chemical composition (e.g., ammonium nitrate), or were some mixture. 15 different sources or chemical compositions were identified as contributing to PM2.5 across the 19 sites. The 6 most common were; aged wood smoke and secondary organic carbon, motor vehicles, primary wood smoke, ammonium nitrate, ammonium sulfate, and fugitive dust. Wood smoke was identified at every site, with both aged and primary wood smoke identified at most sites. Wood smoke contributions to PM2.5 were averaged for the two winter months of December and January, the months when wood smoke in the Northwest U.S. is mainly from residential wood combustion. The total contribution of residential wood combustion, that from primary plus aged smoke, ranged from 11.4% to 92.7% of average December and January PM2.5 depending on the site, with the highest percent contributions occurring in smaller towns that have fewer expected sources of winter PM2.5. Receptor modeling at multiple sites, such as that conducted in this

  8. Residential Tornado Safe Rooms from Commodity Wood Products: Wall Development and Impact Testing

    Science.gov (United States)

    Robert H. Falk; James J. Bridwell; John C. Hermanson

    2015-01-01

    In the United States, tornadoes cause significant damage and result in many injuries and deaths. Although the development and use of tornado safe rooms and shelters have helped reduce the human toll associated with these events, the cost of these structures is often too high for many that could benefit from their use. The development of a residential tornado safe room...

  9. Residential tornado safe room from commodity wood products – design and development

    Science.gov (United States)

    Robert H. Falk; James J. Bridwell

    2018-01-01

    In the United States, tornadoes cause significant damage and result in many injuries and deaths. Although the development and use of tornado safe rooms have helped decrease the human toll associated with these events, the cost of these structures is often too high for many that could benefit from their use. The development of a nonproprietary residential tornado safe...

  10. Chemical source characterization of residential wood combustion emissions in Denver, Colorado; Bakersfield, California; and Mammoth Lakes, California

    International Nuclear Information System (INIS)

    Houck, J.E.; Goulet, J.M.; Chow, J.C.; Watson, J.G.

    1989-01-01

    The chemical composition of residential wood combustion particulate emissions was determined for fireplaces and woodstoves. Burn rates, burn patterns, wood burning appliances, and cordwood types characteristic of Denver, Colorado; Bakersfield, California; and Mammoth Lakes, California, were used during sample collection. Samples were collected using a dilution/cooling system to ensure that condensible compounds were captured. Analyses for 44 chemical species were conducted. Source profiles for use in chemical mass balance (CMB) modeling were calculated from the analytical data. The principal chemical species comprising the profiles were organic compounds and elemental carbon. The minor chemical species were sulfur, chlorine, potassium, sodium, calcium, zinc, nitrate, and ammonium. Virtually all potassium was in a water-soluble form, and sulfur emissions between fireplaces and woodstoves were noted. Area-specific source profiles for fireplaces, woodstoves, and overall residential wood combustion are presented

  11. The greenhouse gas and energy impacts of using wood instead of alternatives in residential construction in the United States

    International Nuclear Information System (INIS)

    Upton, Brad; Miner, Reid; Spinney, Mike; Heath, Linda S.

    2008-01-01

    Data developed by the Consortium for Research on Renewable Industrial Materials were used to estimate savings of greenhouse gas emissions and energy consumption associated with use of wood-based building materials in residential construction in the United States. Results indicate that houses with wood-based wall systems require 15-16% less total energy for non-heating/cooling purposes than thermally comparable houses employing alternative steel- or concrete-based building systems. Results for non-renewable energy consumption are essentially the same as those for total energy, reflecting the fact that most of the displaced energy is in fossil fuels. Over a 100-year period, net greenhouse gas emissions associated with wood-based houses are 20-50% lower than emissions associated with thermally comparable houses employing steel- or concrete-based building systems. Assuming 1.5 million single-family housing starts per year, the difference between wood and non-wood building systems represents about 9.6 Mt of CO 2 equivalents per year. The corresponding energy benefit associated with wood-based building materials is approximately 132 PJ year -1 . These estimates represent about 22% of embodied energy and 27% of embodied greenhouse gas emissions in the residential sector of the US economy. The results of the analysis are very sensitive to assumptions and uncertainties regarding the fate of forestland that is taken out of wood production due to reduced demand for wood, the continued production of co-products where demand for wood products is reduced, and the rate at which carbon accumulates in forests

  12. Simulation and Assessment of Whole Life-Cycle Carbon Emission Flows from Different Residential Structures

    Directory of Open Access Journals (Sweden)

    Rikun Wen

    2016-08-01

    Full Text Available To explore the differences in carbon emissions over the whole life-cycle of different building structures, the published calculated carbon emissions from residential buildings in China and abroad were normalized. Embodied carbon emission flows, operations stage carbon emission flows, demolition and reclamation stage carbon emission flows and total life-cycle carbon emission flows from concrete, steel, and wood structures were obtained. This study is based on the theory of the social cost of carbon, with an adequately demonstrated social cost of carbon and social discount rate. Taking into consideration both static and dynamic situations and using a social discount rate of 3.5%, the total life-cycle carbon emission flows, absolute carbon emission and building carbon costs were calculated and assessed. The results indicated that concrete structures had the highest embodied carbon emission flows and negative carbon emission flows in the waste and reclamation stage. Wood structures that started the life-cycle with stored carbon had the lowest carbon emission flows in the operations stage and relatively high negative carbon emission flows in the reclamation stage. Wood structures present the smallest carbon footprints for residential buildings.

  13. Integration of a wood pellet burner and a Stirling engine to produce residential heat and power

    International Nuclear Information System (INIS)

    Cardozo, Evelyn; Erlich, Catharina; Malmquist, Anders; Alejo, Lucio

    2014-01-01

    The integration a Stirling engine with a pellet burner is a promising alternative to produce heat and power for residential use. In this context, this study is focused on the experimental evaluation of the integration of a 20 kW th wood pellet burner and a 1 kW e Stirling engine. The thermal power not absorbed by the engine is used to produce hot water. The evaluation highlights the effects of pellet type, combustion chamber length and cycling operation on the Stirling engine temperatures and thermal power absorbed. The results show that the position of the Stirling engine is highly relevant in order to utilize as much as possible of the radiative heat from the burner. Within this study, only a 5 cm distance change between the Stirling engine and the pellet burner could result in an increase of almost 100 °C in the hot side of the engine. However, at a larger distance, the temperature of the hot side is almost unchanged suggesting dominating convective heat transfer from the hot flue gas. Ash accumulation decreases the temperature of the hot side of the engine after some cycles of operation when a commercial pellet burner is integrated. The temperature ratio, which is the relation between the minimum and maximum temperatures of the engine, decreases when using Ø8 mm wood pellets in comparison to Ø6 mm pellets due to higher measured temperatures on the hot side of the engine. Therefore, the amount of heat supplied to the engine is increased for Ø8 mm wood pellets. The effectiveness of the engine regenerator is increased at higher pressures. The relation between temperature of the hot side end and thermal power absorbed by the Stirling engine is nearly linear between 500 °C and 660 °C. Higher pressure inside the Stirling engine has a positive effect on the thermal power output. Both the chemical and thermal losses increase somewhat when integrating a Stirling engine in comparison to a stand-alone boiler for only heat production. The overall efficiency

  14. Effect of combustion condition on cytotoxic and inflammatory activity of residential wood combustion particles

    Science.gov (United States)

    Jalava, Pasi I.; Salonen, Raimo O.; Nuutinen, Kati; Pennanen, Arto S.; Happo, Mikko S.; Tissari, Jarkko; Frey, Anna; Hillamo, Risto; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

    2010-05-01

    Residential heating is an important local source of fine particles and may cause significant exposure and health effects in populations. We investigated the cytotoxic and inflammatory activity of particulate emissions from normal (NC) and smouldering (SC) combustion in one masonry heater. The PM 1-0.2 and PM 0.2 samples were collected from the dilution tunnel with a high-volume cascade impactor (HVCI). Mouse RAW 264.7 macrophages were exposed to the PM-samples for 24 h. Inflammatory mediators, (IL-6, TNFα and MIP-2), and cytotoxicity (MTT-test), were measured. Furthermore, apoptosis and cell cycle of macrophages were analyzed. The HVCI particulate samples were characterized for ions, elements and PAH compounds. Assays of elemental and organic carbon were conducted from parallel low volume samples. All the samples displayed mostly dose-dependent inflammatory and cytotoxic activity. SC samples were more potent than NC samples at inducing cytotoxicity and MIP-2 production, while the order of potency was reversed in TNFα production. SC-PM 1-0.2 sample was a significantly more potent inducer of apoptosis than the respective NC sample. After adjustment for the relative toxicity with emission factor (mg MJ -1), the SC-PM emissions had clearly higher inflammatory and cytotoxic potential than the NC-PM emissions. Thus, operational practice in batch burning of wood and the resultant combustion condition clearly affect the toxic potential of particulate emissions.

  15. Online molecular characterization of fine particulate matter in Port Angeles, WA: Evidence for a major impact from residential wood smoke

    Science.gov (United States)

    Gaston, Cassandra J.; Lopez-Hilfiker, Felipe D.; Whybrew, Lauren E.; Hadley, Odelle; McNair, Fran; Gao, Honglian; Jaffe, Daniel A.; Thornton, Joel A.

    2016-08-01

    We present on-line molecular composition measurements of wintertime particulate matter (PM) during 2014 using an iodide-adduct high-resolution, time-of-flight chemical ionization mass spectrometer (HR-TOF-CIMS) coupled to a Filter Inlet for Gases and AEROsols (FIGAERO). These measurements were part of an intensive effort to characterize PM in the region with a focus on ultrafine particle sources. The technique was used to detect and quantify different classes of wood burning tracers, including levoglucosan, methoxyphenols, and nitrocatechols, among other compounds in near real-time. During the campaign, particulate mass concentrations of compounds with the same molecular composition as levoglucosan ranged from 0.002 to 19 μg/m3 with a median mass concentration of 0.9 μg/m3. Wood burning markers, in general, showed a strong diurnal pattern peaking at night and in the early morning. This diurnal profile combined with cold, stagnant conditions, wind directions from predominantly residential areas, and observations of lower combustion efficiency at night support residential wood burning as a dominant source of wintertime PM in Port Angeles. This finding has implications for improving wintertime air quality in the region by encouraging the use of high efficiency wood-burning stoves or other cleaner home heating options throughout the relevant domain.

  16. Effect of Thermal Storage on the Performance of a Wood Pellet-fired Residential Boiler

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Butcher [Brookhaven National Laboratory (BNL), Upton, NY (United States). Sustainable Energy Technologies Dept.

    2017-08-31

    Interest in the direct use of biomass for thermal applications as a renewable technology is increasing as is also focus on air pollutant emissions from these sources and methods to minimize the impact. This work has focused on wood pellet-fired residential boilers, which are the cleanest fuel in this category. In the residential application the load varies strongly over the course of a year and a high fraction of the load is typically under 15% of the maximum boiler capacity. Thermal storage can be used even with boilers which have modulation capacity typically to 30% of the boiler maximum. One common pellet boiler was tested at full load and also at the minimum load used in the U.S. certification testing (15%). In these tests the load was steady over the test period. Testing was also done with an emulated load profile for a home in Albany, N.Y. on a typical January, March, and April day. In this case the load imposed on the boiler varied hourly under computer control, based on the modeled load for the example case used. The boiler used has a nominal output of 25 kW and a common mixed hardwood/softwood commercial pellet was used. Moisture content was 3.77%. A dilution tunnel approach was used for the measurement of particulate emissions, in accordance with U.S. certification testing requirements. The test results showed that the use of storage strongly reduces cycling rates under part load conditions. The transients which occur as these boilers cycle contribute to increased particulate emissions and reduced efficiency. The time period of a full cycle at a given load condition can be increased by increasing the storage tank volume and/or increasing the control differential range. It was shown that increasing the period strongly increased the measured efficiency and reduced the particulate emission (relative to the no storage case). The impact was most significant at the low load levels. Storage tank heat loss is shown to be a significant factor in thermal efficiency

  17. Use of residential wood heating in a context of climate change: a population survey in Québec (Canada

    Directory of Open Access Journals (Sweden)

    Valois Pierre

    2008-05-01

    Full Text Available Abstract Background Wood heating is recommended in several countries as a climate change (CC adaptation measure, mainly to increase the autonomy of households during power outages due to extreme climatic events. The aim of this study was to examine various perceptions and individual characteristics associated with wood heating through a survey about CC adaptations. Methods A telephone survey (n = 2,545 of adults living in the southern part of the province of Québec (Canada was conducted in the early fall season of 2005. The questionnaire used closed questions and measured the respondents' beliefs and current adaptations about CC. Calibration weighting was used to adjust the data analysis for the respondent's age and language under stratified sampling based on health regions. Results More than three out of four respondents had access to a single source of energy at home, which was mainly electricity; 22.2% combined two sources or more; 18.5% heated with wood occasionally or daily during the winter. The prevalence of wood heating was higher in the peripheral regions than in the more urban regions, where there was a higher proportion of respondents living in apartments. The prevalence was also higher with participants completely disagreeing (38.5% with the eventual prohibition of wood heating when there is smog in winter, compared to respondents somewhat disagreeing (24.2% or agreeing (somewhat: 17.5%; completely: 10.4% with the adoption of this strategy. It appears that the perception of living in a region susceptible to winter smog, smog warnings in the media, or the belief in the human contribution to CC, did not influence significantly wood heating practices. Conclusion Increased residential wood heating could very well become a maladaptation to climate change, given its known consequences on winter smog and respiratory health. It would thus be appropriate to implement a long-term national program on improved and controlled residential wood

  18. Heat resistant soy adhesives for structural wood products

    Science.gov (United States)

    Christopher G. Hunt; Charles Frihart; Jane O' Dell

    2009-01-01

    Because load-bearing bonded wood assemblies must support the structure during a fire, the limited softening and depolymerization of biobased polymers at elevated temperatures should be an advantage of biobased adhesives compared to fossil fuel-based adhesives. Because load-bearing bonded wood assemblies must support the structure during a fire, the limited softening...

  19. Post-fire assessment of structural wood members

    Science.gov (United States)

    Robert J. Ross; Brian K. Brashaw; Xiping Wang; Robert H. White; Roy F. Pellerin

    2005-01-01

    Since the interior of a charred wood member normally retains its structural integrity, large structural wood members often do not need to be replaced after a fire. Engineering judgement is required to determine which members can remain and which members need to be replaced or repaired. Due to the lack of established methods to directly determine the residual capacity...

  20.  Thermal Insulation System Made of Wood and Paper for Use in Residential Construction

    Science.gov (United States)

    Zoltán Pásztory; Tibor Horváth; Samuel V. Glass; Samuel L. Zelinka

    2015-01-01

    This article introduces an insulation system that takes advantage of the low thermal conductivity of still air and is made of wood and paper. The insulation, called the Mirrorpanel, is constructed as a panel of closely spaced layers of coated paper and held together in a frame of wood or fiberboard. Panels have been fabricated and tested at the laboratory scale, whole...

  1. Air pollution from residential wood combustion in a Danish village. Measuring campaign and analysis of results

    Energy Technology Data Exchange (ETDEWEB)

    Waahlin, P.; Roerdam Olesen, H.; Bossi, R.; Stubkjaer, J.

    2010-05-15

    A campaign took place in the winter 2006/2007 comprising measurements of many air pollution components at two sites: a wood smoke exposed site within the village Slagslunde, and a background site 500 m outside of the village. The report describes the campaign and its results. A central result is a so-called 'wood smoke source profile', which relates several measures of wood smoke pollution to each other. This is based on a 'cleaned' data set, for which the effect of other sources than wood smoke was small. The wood smoke profile links the measures PM2.5, particle volume, soot, monosaccharide anhydrides (levoglucosan and mannosan) and different PAHs to each other. Particle number N does not have a close link to the other measures. (author)

  2. Air pollution from residential wood combustion in a Danish village. Measuring campaign and analysis of results

    Energy Technology Data Exchange (ETDEWEB)

    Waahlin, P; Roerdam Olesen, H; Bossi, R; Stubkjaer, J

    2010-05-15

    A campaign took place in the winter 2006/2007 comprising measurements of many air pollution components at two sites: a wood smoke exposed site within the village Slagslunde, and a background site 500 m outside of the village. The report describes the campaign and its results. A central result is a so-called 'wood smoke source profile', which relates several measures of wood smoke pollution to each other. This is based on a 'cleaned' data set, for which the effect of other sources than wood smoke was small. The wood smoke profile links the measures PM2.5, particle volume, soot, monosaccharide anhydrides (levoglucosan and mannosan) and different PAHs to each other. Particle number N does not have a close link to the other measures. (author)

  3. The structure of residential energy demand in Greece

    International Nuclear Information System (INIS)

    Rapanos, Vassilis T.; Polemis, Michael L.

    2006-01-01

    This paper attempts to shed light on the determinants of residential energy demand in Greece, and to compare it with some other OECD countries. From the estimates of the short-run and long-run elasticities of energy demand for the period 1965-1999, we find that residential energy demand appears to be price inelastic. Also, we do not find evidence of a structural change probably because of the low efficiency of the energy sector. We find, however, that the magnitude of the income elasticity varies substantially between Greece and other OECD countries

  4. DEVELOPMENT OF STRUCTURES FROM SOLID WOOD FOR OBJECTS OF INFRASTRUCTURE

    OpenAIRE

    Konstantin P. Pyatikrestovsky; Vladimir I. Travush; Alexander A. Pogoreltsev; Alexander A. Klyukin

    2018-01-01

    New prefabricated lightweight structures made of solid wood with connections for joining and building metal screws for wood are proposed. Manufacture and assembly of basic elements-bars with a cross-section of 15x15 cm can be carried out in line conditions on the simplest woodworking equipment. The use of local tim-ber material has a number of advantages (ecological, economic and operational). The description of structures with manufacturing process, examples of buildings with vaulted and hip...

  5. STATUS OF LEAN MANUFACTURING IMPLEMENTATION ON SECONDARY WOOD INDUSTRIES INCLUDING RESIDENTIAL, CABINET, MILLWORK, AND PANEL MARKETS

    OpenAIRE

    Adrian Pirraglia; Daniel Saloni; Herman van Dyk

    2009-01-01

    Lean Manufacturing has helped several industries to achieve operational and manufacturing excellence by increasing productivity and enhancing quality, while reducing waste and costs. However, the wood industry has been historically slow in adopting this philosophy and its many tools. In times when overseas competition has taken big portions of the traditional market share for U.S based wood industries, it has become important that companies start to take actions in order to regain competitive...

  6. Wood-based composite materials : panel products, glued-laminated timber, structural composite lumber, and wood-nonwood composite materials

    Science.gov (United States)

    Nicole M. Stark; Zhiyong Cai; Charles Carll

    2010-01-01

    This chapter gives an overview of the general types and composition of wood-based composite products and the materials and processes used to manufacture them. It describes conventional wood-based composite panels and structural composite materials intended for general construction, interior use, or both. This chapter also describes wood–nonwood composites. Mechanical...

  7. Finite element modeling of Balsa wood structures under severe loadings

    International Nuclear Information System (INIS)

    Toson, B.; Pesque, J.J.; Viot, P.

    2014-01-01

    In order to compute, in various situations, the requirements for transporting packages using Balsa wood as an energy absorber, a constitutive model is needed that takes into account all of the specific characteristics of the wood, such as its anisotropy, compressibility, softening, densification, and strain rate dependence. Such a model must also include the treatment of rupture of the wood when it is in traction. The complete description of wood behavior is not sufficient: robustness is also necessary because this model has to work in presence of large deformations and of many other external nonlinear phenomena in the surrounding structures. We propose such a constitutive model that we have developed using the commercial finite element package ABAQUS. The necessary data were acquired through an extensive compilation of the existing literature with the augmentation of personal measurements. Numerous validation tests are presented that represent different impact situations that a transportation cask might endure. (authors)

  8. Time-resolved characterization of primary emissions from residential wood combustion appliances.

    Science.gov (United States)

    Heringa, M F; DeCarlo, P F; Chirico, R; Lauber, A; Doberer, A; Good, J; Nussbaumer, T; Keller, A; Burtscher, H; Richard, A; Miljevic, B; Prevot, A S H; Baltensperger, U

    2012-10-16

    Primary emissions from a log wood burner and a pellet boiler were characterized by online measurements of the organic aerosol (OA) using a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and of black carbon (BC). The OA and BC concentrations measured during the burning cycle of the log wood burner, batch wise fueled with wood logs, were highly variable and generally dominated by BC. The emissions of the pellet burner had, besides inorganic material, a high fraction of OA and a minor contribution of BC. However, during artificially induced poor burning BC was the dominating species with ∼80% of the measured mass. The elemental O:C ratio of the OA was generally found in the range of 0.2-0.5 during the startup phase or after reloading of the log wood burner. During the burnout or smoldering phase, O:C ratios increased up to 1.6-1.7, which is similar to the ratios found for the pellet boiler during stable burning conditions and higher than the O:C ratios observed for highly aged ambient OA. The organic emissions of both burners have a very similar H:C ratio at a given O:C ratio and therefore fall on the same line in the Van Krevelen diagram.

  9. Start-up emissions from residential down-draught wood log boilers

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, E. (Luleaa Univ. of Technology (Sweden). Energy Technology Centre in Piteaa), Email: esbjorn.pettersson@ltu.se

    2009-07-01

    Start-up emissions can be substantial and even dominating in real use. There are few published investigations regarding the relative importance of different parameters on the start-up emissions. It has though recently been stated that for down-draught boilers, best results are achieved if the wood charge is ignited fairly close to the secondary chamber. The objective of the experimental work was to evaluate the effect of different fuel and design parameters on the start-up emissions, using experimental design which enables a direct comparison between different parameters, using three levels of preheating of secondary air, electric preheating of primary air, different moisture and size of the start wood as well as different amounts of birch bark, which was used to spread the fire during the start. The boiler did not use a bypass damper and the full fuel charge was added before igniting the start wood through an ignition door situated slightly above the grate. The only significant results for the four parameters were that smaller and drier start wood gave lower start-up emissions. Extra amount of birch bark gave the same result. The most important parameters are the fuel parameters, which mean that the result is generally applicable. (orig.)

  10. Retene Emission from Residential Solid Fuels in China and Evaluation of Retene as a Unique Marker for Soft Wood Combustion

    Science.gov (United States)

    Shen, Guofeng; Tao, Shu; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Yang, Yifeng; Wang, Wei; Wang, Xilong; Massey Simonich, Staci L.

    2012-01-01

    Retene (1-methyl-7-isopropylphenanthrene) is often used as a marker for softwood combustion and for polycyclic aromatic hydrocarbon (PAH) source apportionment. The emission factors of retene (EFRET) from 11 crop residues, 27 firewood and 5 coals were measured using traditional rural Chinese stoves. Retene was measured in combustion emissions from all of the residential fuels tested and EFRET varied significantly among the fuels due to the differences in fuel properties and combustion conditions. EFRET for pine (0.34±0.08 mg/kg) and larch (0.29±0.22 mg/kg) were significantly higher than those of other wood types, including fir and cypress (0.081±0.058 mg/kg). However, EFRET for crop residues varied from 0.048±0.008 to 0.37±0.14 mg/kg and were not significantly lower than those for softwood (0.074±0.026 to 0.34±0.08 mg/kg). The EFRET for coal were very high and ranged from 2.2±1.5 (anthracite briquette) to 187±113 mg/kg (raw bituminous chunk). EFRET was positively correlated with EFs of co-emitted particulate matter (EFPM) and phenanthrene (EFPHE) for crop residue and coal, but not for wood. In addition, the ratios of EFPHE/EFRET and EFPM/EFRET for coals were much lower than those for crop residues and wood. These data suggest that retene is not a unique PAH marker for softwood combustion and that coal combustion, in particular, should be taken into account when retene is used for PAH source apportionment. PMID:22452486

  11. Air quality and residential wood combustion - application of the model system SIMAIRrwc for some Swedish municipalities; Luftkvalitet och smaaskalig biobraensleeldning. Tillaempningar av SIMAIRved foer naagra kommuner

    Energy Technology Data Exchange (ETDEWEB)

    Omstedt, Gunnar; Andersson, Stefan; Johansson, Christer; Loefgren, Bengt-Erik

    2008-11-15

    SIMAIRrwc is a Web based evaluation tool for meeting the EU directive on air pollution limits in residential areas using wood combustion. The background is a four-year research program (2001-2004) called Biomass Combustion Health and Environment. Some conclusions from this program were that emissions from small scale wood combustion can influence human health mainly due to high emitting old wood stoves during cold weather conditions and that the air quality in such areas can improve significantly if old wood stoves were replaced by modern wood boilers attached to a storage tank or with a pellet boiler. SIMAIRrwc is based on the same principles as SIMAIRroad, which is a Web based evaluation tool for road traffic i.e. coupled model system using different models on local, urban and regional geographical scales, best available emission data, but at the same time presented in a very simplified way. In this project SIMAIRrwc has been applied in five different Swedish municipalities. The aim has been to apply and improve the model in cooperation with the municipalities. The conclusions from the project are: Small scale wood combustions in residential areas are local problems which sometimes include only a few houses and/or wood-burners. Air quality problems related to the EU directive are mainly due to particles. Combinations of residential areas with wood combustion and emissions from nearby dense traffic roads might give rise to bad air quality. Actions require knowledge about individual equipment which needs information from the local chimney sweeps. The best way to identify problem areas is to use model calculations. If model calculations indicate risks of exceeding air quality limits, then new calculations should be made with improved input data taking into account for example information of district heating or other installations that can effect the emissions. Before actions are taken it may also be useful to make measurements. The measurement site can then be

  12. Tools to Understand Structural Property Relationships for Wood Cell Walls

    Science.gov (United States)

    Joseph E. Jakes; Daniel J. Yelle; Charles R. Frihart

    2011-01-01

    Understanding structure-property relationships for wood cell walls has been hindered by the complex polymeric structures comprising these cell walls and the difficulty in assessing meaningful mechanical property measurements of individual cell walls. To help overcome these hindrances, we have developed two experimental methods: 1) two-dimensional solution state nuclear...

  13. Seismic Evaluation of Structural Insulated Panels in Comparison with Wood-Frame Panels

    Directory of Open Access Journals (Sweden)

    Stefanie Terentiuk

    2014-07-01

    Full Text Available Structural Insulated Panel (SIP wall systems have been used in residential and light commercial buildings for the past sixty years. Lack of sufficient published research on racking load performance and limited understanding of the influence of fastener types on seismic response has been a deterrent in widespread use of the wall system in seismically active areas. This paper presents the results of a study involving a total of twenty one 2.4 m × 2.4 m shear walls tested under monotonic and cyclic loading. Four different 114 mm thick SIP panel configurations and one traditional wood frame wall were tested under monotonic loading according to ASTM E 564-06; and thirteen 114 mm thick SIP panels and three wood frame walls were tested under the CUREE loading protocol according to ASTM E 2126-11. Parameters such as fastener type; spline design; hold-down anchor location; and sheathing bearing were adjusted throughout the testing in order to determine their effects on the SIP’s performance. Performance parameters such as peak load and displacement; energy dissipation; allowable drift load capacity and seismic compatibility were determined for all of the specimens. Such parameters were then used to demonstrate the SIP walls’ compatibility with the wood frame walls and to determine the efficiency of the different SIP wall configuration and spline systems employed.

  14. Lifting and protecting residential structures from subsidence damage using airbags

    International Nuclear Information System (INIS)

    Triplett, T.L.; Bennett, R.M.

    1998-01-01

    Conventional practice in protecting residential structures from subsidence damage concentrates on saving the superstructure. The foundation is sacrificed, even though it represents the structural component with the greatest replacement cost. In this study, airbags were used to lift a 20 ft x 30 ft structure to test their ability to protect both the foundation and superstructure from ground settlement. Two contiguous sides of the test foundation were unreinforced, and the other two contiguous sides incorporated footing and wall reinforcement. The airbags successfully lifted the structure without causing damage, even on the unreinforced sides. This paper gives a procedure for determining airbag spacing, and describes installation and operation techniques of the airbags. The paper then focuses on the performance of the airbags in lifting the structure, and shows that airbags can preserve existing foundations during subsidence movements

  15. Nighttime residential wood burning evidenced from an indirect method for estimating real-time concentration of particulate organic matter (POM)

    International Nuclear Information System (INIS)

    Sciare, J.; Sarda-Esteve, R.; Favez, O.; Cachier, H.; Aymoz, G.; Laj, P.

    2008-01-01

    Real-time analyzers of selected chemical components (sulfate, nitrate, Black Carbon) and integrative aerosol parameters (particulate matter and light scattering coefficient) were implemented for a 2-week campaign (November-December 2005) in a suburban area of Clermont-Ferrand (France) in order to document fast changes in the chemical composition of submicron aerosols. Measurements of particulate organic matter (POM) were not available in the field but were indirectly estimated from time-resolved (3-min) reconstruction of the light scattering coefficient. This methodology offered the opportunity to investigate almost real-time and artifact-free POM concentrations even at low concentrations (typically below 0.1 mu g m(-3)). The overall uncertainties associated with this POM calculation were of the order of 20%, which are comparable to those commonly referred in literature for POM calculation or measurements. A chemical mass balance (CMB) of PM1 was performed using the derived POM concentrations and showed a very good correlation (slope = 0.93; r(2) = 0.91, N = 663) with real-time PM1 measurements obtained from R and P TEOM-FDMS, demonstrating the consistency of our approach. Important diurnal variations were observed in POM concentrations, with a dominant contribution of POM from fossil fuel origin during daytime and a dominant contribution of POM from residential wood burning at night. POM was calculated to contribute as much as 70% of PM1 during our study, pointing out the major role of carbonaceous aerosols at this period of the year at our residential area. (authors)

  16. Influence of firebed temperature on inorganic particle emissions in a residential wood pellet boiler

    Science.gov (United States)

    Gehrig, Matthias; Jaeger, Dirk; Pelz, Stefan K.; Weissinger, Alexander; Groll, Andreas; Thorwarth, Harald; Haslinger, Walter

    2016-07-01

    The temperature-dependent release of inorganic elements is the first step of the main formation pathway of particle emissions in automatically fired biomass burners. To investigate this step, a residential pellet boiler with an underfeed-burner was equipped with a direct firebed cooling. This test setup enabled decreased firebed temperatures without affecting further parameters like air flow rates or oxygen content in the firebed. A reduction of particle emissions in PM1-fraction at activated firebed cooling was found by impactor measurement and by optical particle counter. The affected particles were found in the size range boiler ash showed no statistically significant differences due to the firebed cooling. Therefore, our results indicate that the direct firebed cooling influenced the release of potassium (K) without affecting other chemical reactions.

  17. Extractive and anatomical wood structure effects on mechanical properties of Caoba wood (Swietenia macrophylla King)

    International Nuclear Information System (INIS)

    Arevalo Fuentes Rosven Libardo; Hernandez Roger

    2008-01-01

    The compression tangential to grain of samples of mahogany wood from Peru was examined at different relative humidity levels at 25 Celsius degrade to determine the influence of both extractives and anatomical structure. Matched samples were used to assess the percentage of extractive components by extraction with solvents of increasing polarity: cyclohexane, dichloromethane, acetone, methanol and hot water. Additionally, fourteen anatomical parameters were determined by image analysis. Stepwise regression analysis concluded that mainly anatomical features, such as rays and vessels, rather than extractives, affect the mechanical behaviour of mahogany. These findings are agree with earlier results showing a negative effect of large and multiseriate rays on the mechanical properties of wood when loaded perpendicularly to their long axis. The influence of lumen located extracts soluble in dichloromethane might disallow deformations. Finally, it is postulated that hot water extracts may play a plasticizing role in this species.

  18. 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...

  19. Arsenic levels in wipe samples collected from play structures constructed with CCA-treated wood: Impact on exposure estimates

    Energy Technology Data Exchange (ETDEWEB)

    Barraj, Leila M. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States)], E-mail: lbarraj@exponent.com; Scrafford, Carolyn G. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States); Eaton, W. Cary [RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709 (United States); Rogers, Robert E.; Jeng, Chwen-Jyh [Toxcon Health Sciences Research Centre Inc., 9607 - 41 Avenue, Edmonton, Alberta, T6E 5X7 (Canada)

    2009-04-01

    Lumber treated with chromated copper arsenate (CCA) has been used in residential outdoor wood structures and playgrounds. The U.S. EPA has conducted a probabilistic assessment of children's exposure to arsenic from CCA-treated structures using the Stochastic Human Exposure and Dose Simulation model for the wood preservative scenario (SHEDS-Wood). The EPA assessment relied on data from an experimental study using adult volunteers and designed to measure arsenic in maximum hand and wipe loadings. Analyses using arsenic handloading data from a study of children playing on CCA-treated play structures in Edmonton, Canada, indicate that the maximum handloading values significantly overestimate the exposure that occurs during actual play. The objective of our paper is to assess whether the dislodgeable arsenic residues from structures in the Edmonton study are comparable to those observed in other studies and whether they support the conclusion that the values derived by EPA using modeled maximum loading values overestimate hand exposures. We compared dislodgeable arsenic residue data from structures in the playgrounds in the Edmonton study to levels observed in studies used in EPA's assessment. Our analysis showed that the dislodgeable arsenic levels in the Edmonton playground structures are similar to those in the studies used by EPA. Hence, the exposure estimates derived using the handloading data from children playing on CCA-treated structures are more representative of children's actual exposures than the overestimates derived by EPA using modeled maximum values. Handloading data from children playing on CCA-treated structures should be used to reduce the uncertainty of modeled estimates derived using the SHEDS-Wood model.

  20. DEVELOPMENT OF STRUCTURES FROM SOLID WOOD FOR OBJECTS OF INFRASTRUCTURE

    Directory of Open Access Journals (Sweden)

    Konstantin P. Pyatikrestovsky

    2018-03-01

    Full Text Available New prefabricated lightweight structures made of solid wood with connections for joining and building metal screws for wood are proposed. Manufacture and assembly of basic elements-bars with a cross-section of 15x15 cm can be carried out in line conditions on the simplest woodworking equipment. The use of local tim-ber material has a number of advantages (ecological, economic and operational. The description of structures with manufacturing process, examples of buildings with vaulted and hipped roofing, connection arrangement, preparation of experimental samples with the use of new equipment of the National Research Moscow State University of Civil Engineering are given. The method of analysis with allowance for plastic deformations is under consideration. It provides additional economic advantages. The analysis is carried out by the method of integral estimates developed by Prof. V.M. Bondarenko for reinforced concrete structures and adapted to wooden structures by Prof. K.P. Pyatikrestovsky. Special strength criteria are used for the analysis of decks working together with the ribs (in a combined stressed state. It is planned to build buildings for various purposes in the ar-eas of development of the Far North of Russia.

  1. Contaminant deposition building shielding factors for US residential structures

    International Nuclear Information System (INIS)

    Dickson, E D; Hamby, D M; Eckerman, K F

    2015-01-01

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations from contaminant deposition on the roof and surrounding ground as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement as well for single-wide manufactured housing-unit. (paper)

  2. Cloud immersion building shielding factors for US residential structures

    International Nuclear Information System (INIS)

    Dickson, E D; Hamby, D M

    2014-01-01

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement, as well for single-wide manufactured housing-units. (paper)

  3. Contaminant deposition building shielding factors for US residential structures.

    Science.gov (United States)

    Dickson, Elijah; Hamby, David; Eckerman, Keith

    2017-10-10

    This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations from contaminant deposition on the roof and surrounding ground as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement as well for single-wide manufactured housing-unit. © 2017 IOP Publishing Ltd.

  4. Functional relationships between wood structure and vulnerability to xylem cavitation in races of Eucalyptus globulus differing in wood density.

    Science.gov (United States)

    Barotto, Antonio José; Monteoliva, Silvia; Gyenge, Javier; Martinez-Meier, Alejandro; Fernandez, María Elena

    2018-02-01

    Wood density can be considered as a measure of the internal wood structure, and it is usually used as a proxy measure of other mechanical and functional traits. Eucalyptus is one of the most important commercial forestry genera worldwide, but the relationship between wood density and vulnerability to cavitation in this genus has been little studied. The analysis is hampered by, among other things, its anatomical complexity, so it becomes necessary to address more complex techniques and analyses to elucidate the way in which the different anatomical elements are functionally integrated. In this study, vulnerability to cavitation in two races of Eucalyptus globulus Labill. with different wood density was evaluated through Path analysis, a multivariate method that allows evaluation of descriptive models of causal relationship between variables. A model relating anatomical variables with wood properties and functional parameters was proposed and tested. We found significant differences in wood basic density and vulnerability to cavitation between races. The main exogenous variables predicting vulnerability to cavitation were vessel hydraulic diameter and fibre wall fraction. Fibre wall fraction showed a direct impact on wood basic density and the slope of vulnerability curve, and an indirect and negative effect over the pressure imposing 50% of conductivity loss (P50) through them. Hydraulic diameter showed a direct negative effect on P50, but an indirect and positive influence over this variable through wood density on one hand, and through maximum hydraulic conductivity (ks max) and slope on the other. Our results highlight the complexity of the relationship between xylem efficiency and safety in species with solitary vessels such as Eucalyptus spp., with no evident compromise at the intraspecific level. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Yu, Shun; Yan, Min; Berglund, Lars

    2016-04-11

    Optically transparent wood (TW) with transmittance as high as 85% and haze of 71% was obtained using a delignified nanoporous wood template. The template was prepared by removing the light-absorbing lignin component, creating nanoporosity in the wood cell wall. Transparent wood was prepared by successful impregnation of lumen and the nanoscale cellulose fiber network in the cell wall with refractive-index-matched prepolymerized methyl methacrylate (MMA). During the process, the hierarchical wood structure was preserved. Optical properties of TW are tunable by changing the cellulose volume fraction. The synergy between wood and PMMA was observed for mechanical properties. Lightweight and strong transparent wood is a potential candidate for lightweight low-cost, light-transmitting buildings and transparent solar cell windows.

  6. Chemical composition and speciation of particulate organic matter from modern residential small-scale wood combustion appliances.

    Science.gov (United States)

    Czech, Hendryk; Miersch, Toni; Orasche, Jürgen; Abbaszade, Gülcin; Sippula, Olli; Tissari, Jarkko; Michalke, Bernhard; Schnelle-Kreis, Jürgen; Streibel, Thorsten; Jokiniemi, Jorma; Zimmermann, Ralf

    2018-01-15

    Combustion technologies of small-scale wood combustion appliances are continuously developed decrease emissions of various pollutants and increase energy conversion. One strategy to reduce emissions is the implementation of air staging technology in secondary air supply, which became an established technique for modern wood combustion appliances. On that account, emissions from a modern masonry heater fuelled with three types of common logwood (beech, birch and spruce) and a modern pellet boiler fuelled with commercial softwood pellets were investigated, which refer to representative combustion appliances in northern Europe In particular, emphasis was put on the organic constituents of PM2.5, including polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs) and phenolic species, by targeted and non-targeted mass spectrometric analysis techniques. Compared to conventional wood stoves and pellet boilers, organic emissions from the modern appliances were reduced by at least one order of magnitude, but to a different extent for single species. Hence, characteristic ratios of emission constituents and emission profiles for wood combustion identification and speciation do not hold for this type of advanced combustion technology. Additionally, an overall substantial reduction of typical wood combustion markers, such as phenolic species and anhydrous sugars, were observed. Finally, it was found that slow ignition of log woods changes the distribution of characteristic resin acids and phytosterols as well as their thermal alteration products, which are used as markers for specific wood types. Our results should be considered for wood combustion identification in positive matrix factorisation or chemical mass balance in northern Europe. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Influence of ultrasound pretreatment on wood physiochemical structure.

    Science.gov (United States)

    He, Zhengbin; Wang, Zhenyu; Zhao, Zijian; Yi, Songlin; Mu, Jun; Wang, Xiaoxu

    2017-01-01

    As an initial step to increase the use of renewable biomass resources, this study was aimed at investigating the effects of ultrasound pretreatment on structural changes of wood. Samples were pretreated by ultrasound with the power of 300W and frequency of 28kHz in aqueous soda solution, aqueous acetic acid, or distilled water, then pretreated and control samples were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results shown that ultrasound pretreatment is indeed effective in modifying the physiochemical structure of eucalyptus wood; the pretreatment decreased the quantity of alkali metals (e.g., potassium, calcium and magnesium) in the resulting material. Compared to the control group, the residual char content of samples pretreated in aqueous soda solution increased by 10.08%-20.12% and the reaction temperature decreased from 361°C to 341°C, however, in samples pretreated by ultrasound in acetic solution or distilled water, the residual char content decreased by 12.40%-21.45% and there were no significant differences in reactivity apart from a slightly higher maximum reaction rate. Ultrasound pretreatment increased the samples' crystallinity up to 35.5% and successfully removed cellulose, hemicellulose, and lignin from the samples; the pretreatment also increased the exposure of the sample to the treatment solutions, broke down sample pits, and generated collapses and microchannels on sample pits, and removed attachments in the samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. 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.

  9. Experimental characterization, modeling and simulation of a wood pellet micro-combined heat and power unit used as a heat source for a residential building

    Energy Technology Data Exchange (ETDEWEB)

    Thiers, Stephane; Aoun, Bernard; Peuportier, Bruno [MINES ParisTech, CEP - Centre Energetique et Procedes, 60 Boulevard St Michel, 75272 Paris Cedex 06 (France)

    2010-06-15

    Cogeneration provides heat and power in a more efficient way than separate production. Micro-cogeneration (micro-CHP) is an emerging solution for the improvement of energy and environmental assessments of residential buildings. A wood pellet Stirling engine micro-CHP unit has been studied in order to characterize its annual performance when integrated to a building. First, through a test bench experiment, both transient and steady state behaviors of the micro-CHP unit have been characterized and modeled. Then a more complete model representing a hot water and heating system including the micro-CHP unit and a stratified storage tank has been carried out. This model has been coupled to a building model. A sensitivity analysis by simulation shows that the dimensioning of different elements of the system strongly influences its global energy performance. (author)

  10. Tomography reconstruction methods for damage diagnosis of wood structure in construction field

    Science.gov (United States)

    Qiu, Qiwen; Lau, Denvid

    2018-03-01

    The structural integrity of wood building element plays a critical role in the public safety, which requires effective methods for diagnosis of internal damage inside the wood body. Conventionally, the non-destructive testing (NDT) methods such as X-ray computed tomography, thermography, radar imaging reconstruction method, ultrasonic tomography, nuclear magnetic imaging techniques, and sonic tomography have been used to obtain the information about the internal structure of wood. In this paper, the applications, advantages and disadvantages of these traditional tomography methods are reviewed. Additionally, the present article gives an overview of recently developed tomography approach that relies on the use of mechanical and electromagnetic waves for assessing the structural integrity of wood buildings. This developed tomography reconstruction method is believed to provide a more accurate, reliable, and comprehensive assessment of wood structural integrity

  11. Nondestructive methods for the structural evaluation of wood floor systems in historic buildings : preliminary results : [abstract

    Science.gov (United States)

    Zhiyong Cai; Michael O. Hunt; Robert J. Ross; Lawrence A. Soltis

    1999-01-01

    To date, there is no standard method for evaluating the structural integrity of wood floor systems using nondestructive techniques. Current methods of examination and assessment are often subjective and therefore tend to yield imprecise or variable results. For this reason, estimates of allowable wood floor loads are often conservative. The assignment of conservatively...

  12. Nondestructive structural evaluation of wood floor systems with a vibration technique.

    Science.gov (United States)

    Xiping Wang; Robert J. Ross; Lawrence Andrew Soltis

    2002-01-01

    The objective of this study was to determine if transverse vibration methods could be used to effectively assess the structural integrity of wood floors as component systems. A total of 10 wood floor systems, including 3 laboratory-built floor sections and 7 in-place floors in historic buildings, were tested. A forced vibration method was applied to the floor systems...

  13. Evaluation of Methods for Physical Characterization of the Fine Particle Emissions from Two Residential Wood Combustion Appliances

    Science.gov (United States)

    The fine particulate matter (PM) emissions from a U. S. certified non-catalytic wood stove and a zero clearance fireplace burning Quercus rubra L. (northern red oak) and Pseudotsuga menziesii (Douglas fir) cordwood each at two different moisture levels were determined. Emission t...

  14. Solid wood timber products consumption in major end uses in the United States, 1950-2009 : a technical document supporting the Forest Service 2010 RPA assessment

    Science.gov (United States)

    David B. McKeever; James L. Howard

    2011-01-01

    Solid wood timber products provide important raw materials to the construction, manufacturing, and shipping sectors of the U.S. economy. Nearly all new single-family houses and low-rise multifamily residential structures are wood framed and sheathed. Large amounts of solid wood timber products are also used in the construction of new nonresidential buildings, and in...

  15. 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...

  16. Analysis of existing structure and emissions of wood combustion plants for the production of heat and electricity in Bavaria

    International Nuclear Information System (INIS)

    Joa, Bettina

    2014-01-01

    This work deals with the detailed analysis of the existing structure of all Bavarian wood burning plants for the generation of heat and electricity as well as the determination of the resulting emission emissions in 2013. The number of wood burning plants in the single-chamber fireplaces, wood central heating and wood-fired heating plants which are in operation in the year 2013 were determined, and how many plants are existing in the various areas like pellet stoves, traditional ovens, wood-burning fireplace, pellet central heating systems, wood chips central heating systems, fire-wood central heating systems, wood combined heat and power plant (electricity and heat) and wood power plants (heat). In addition, the regional distribution of the wood burning plants in the Bavarian governmental districts is investigated as well as the type and amount of energy produced by them (heat, electricity). [de

  17. Residential space heating with wood burning stoves. Energy efficiency and indoor climate; Boligopvarmning ved braendefyring. Energieffektivitet og indeklima

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Ole Michael; Afshari, A.; Bergsoee, N.C.; Carvalho, R. [Miljoestyrelsen, Copenhagen (Denmark); Aalborg Univ.. Statens Byggeforskningsinstitut, Aalborg (Denmark))

    2012-11-01

    Two issues turn up concerning how to use wood-burning stoves in modern homes. The first is whether wood-burning stoves in future may still act as a genuine heat source, given that new and refurbished single-family houses retain the heat much better than older ones and therefore need less and less energy for space heating. The second issue is whether it will still be possible to use wood-burning stoves in modern houses where the air exchange is controlled by mechanical ventilation or possibly heat recovery. It is a question whether firing techniques can be developed that will work in airtight houses with mechanical ventilation and negative pressure, so that harmful particle emissions can be avoided. To illustrate the first issue, a field study was designed to look carefully at seven modern wood-burning stoves that were set up in six new houses and one older house and investigated, both in terms of firing and heat release. As a background for this part of the study, a heat balance calculation was made for each house. The question is, whether wood-burning stoves will also in the future have a role to play as a heating source. Modern houses grow ever tighter and only need to be supplied with a small quantity of heat. The new Danish Buildings Requirement, 2010 has resulted in a further reduction of 25 % of the energy demand, including the energy supply for heating. However, the new requirements imply that the heating season eventually become so short that a traditional central heating installation becomes superfluous. This means that by using the small amounts of wood cut in gardens and hedgerows of the neighbourhood, a wood-burning stove will, in principle, cover the heating demand. Therefore, the question is rather whether a wood-burning stove is manufactured that can successfully be adapted to new houses. As a consequence of this development, future stoves must be further scaled down in order to meet the heating demand of a modern low-energy house and the stoves must

  18. Synthesis of wood treatment alternatives for timber railroad structures.

    Science.gov (United States)

    2011-12-01

    A wealth of information exists on various wood preservatives, treatment techniques, curing practices, and other engineered : controls, along with alternative materials for replacement. This study was initiated to review and synthesize available : inf...

  19. Flume experiments on scour downstream of wood stream restoration structures

    Science.gov (United States)

    Pagliara, Stefano; Kurdistani, Sahameddin Mahmoudi

    2017-02-01

    River restoration aims to improve physical natural form and processes of a river. Techniques to control the riverbed, stabilize channel alignment, protect stream banks, and rebuild the natural habitat are an important part of river restoration projects. Rivers can be stabilized and habitat restored through techniques such as rebuilding meanders and pool-riffle sequences and managing large wood. Structures that limit channel width to accelerate the normal flows through the constricted section are referred to as stream deflectors. Single-wing, double-wing and triangular deflectors are the most commonly used types of this measure. Log-frame deflectors consist of a triangular log frame filled with rock. Deflector constructions singly or in series in low gradient meandering streams, divert base flows toward the center of the channel and, under certain conditions, increase the depth and velocity of flow thereby creating scour pools and enhancing fish habitat. Scour characteristics and morphologies downstream of log-frame deflectors have been analyzed at the hydraulic laboratory of the University of Pisa. All experiments have been carried out in clear water conditions. The results showed that the tailwater depth plays an important role on scour characteristics. In addition, it was experimentally proven that using log-frame deflectors instead of log-deflectors result in a better river bank protection. In this case, for all the tested hydraulic conditions, the scour hole never occurred close to the channel bank. Useful empirical relationships have been proposed in order to evaluate the main features of the scour geometry.

  20. Wood-damaging fungi in truss structures of baroque churches

    Czech Academy of Sciences Publication Activity Database

    Frankl, Jiří

    2015-01-01

    Roč. 29, č. 5 (2015), s. 04014138 ISSN 0887-3828 R&D Projects: GA ČR(CZ) GPP105/11/P628; GA MŠk(CZ) LO1219 Keywords : wood * biological damage * wood-damaging fungi Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 0.893, year: 2015 http://ascelibrary.org/doi/abs/10.1061/(ASCE)CF.1943-5509.0000632

  1. Reliability and service life of wood structures and buildings

    OpenAIRE

    Zdeňka Havířová; Pavel Kubů

    2005-01-01

    Service life of constructions and buildings of wood is dependent on temperature and moisture conditions in layers of the building cladding where the wood framework is built in. Temperature/moisture conditions or the corresponding equilibrium moisture content (EMC) of the construction show considerable effects on the functional reliability of the whole building from the viewpoint of mechanical resistance and stability (ER1), energy savings and thermal protection (ER6) and hygiene, health and e...

  2. Estimated health impact of a shift from light fuel to residential wood-burning in Upper Austria.

    Science.gov (United States)

    Haluza, Daniela; Kaiser, August; Moshammer, Hanns; Flandorfer, Claudia; Kundi, Michael; Neuberger, Manfred

    2012-07-01

    The dependency on carbon-based fossil energy and growing awareness of climate change issues has induced ambitious policy initiatives to promote renewable energy sources for indoor heating. Combustion of regionally available material such as wood is considered a carbon-neutral alternative for oil and gas, but unregulated revival of wood stoves may cause detrimental health effects. For the prognosis of the health impact of air pollution due to the use of wood stoves, Upper Austria served for a case study. On the basis of recent measurements of particulate matter fuel oil by either fossil gas or biomass, and for scenario 3, replacement of light fuel oil by biomass only. Compared with the current exposure from scenario 1, the increased annual mean PM10 levels are estimated to lead to 101 (95% CI 56;146) and 174 (95% CI 92;257) additional deaths among 1.4 million inhabitants per year for scenarios 2 and 3, respectively. Without adequate strategies for reducing the emissions of domestic heating facilities, replacement of fossil energy sources could lead to an increased health risk.

  3. Processing bulk natural wood into a high-performance structural material

    Science.gov (United States)

    Song, Jianwei; Chen, Chaoji; Zhu, Shuze; Zhu, Mingwei; Dai, Jiaqi; Ray, Upamanyu; Li, Yiju; Kuang, Yudi; Li, Yongfeng; Quispe, Nelson; Yao, Yonggang; Gong, Amy; Leiste, Ulrich H.; Bruck, Hugh A.; Zhu, J. Y.; Vellore, Azhar; Li, Heng; Minus, Marilyn L.; Jia, Zheng; Martini, Ashlie; Li, Teng; Hu, Liangbing

    2018-02-01

    Synthetic structural materials with exceptional mechanical performance suffer from either large weight and adverse environmental impact (for example, steels and alloys) or complex manufacturing processes and thus high cost (for example, polymer-based and biomimetic composites). Natural wood is a low-cost and abundant material and has been used for millennia as a structural material for building and furniture construction. However, the mechanical performance of natural wood (its strength and toughness) is unsatisfactory for many advanced engineering structures and applications. Pre-treatment with steam, heat, ammonia or cold rolling followed by densification has led to the enhanced mechanical performance of natural wood. However, the existing methods result in incomplete densification and lack dimensional stability, particularly in response to humid environments, and wood treated in these ways can expand and weaken. Here we report a simple and effective strategy to transform bulk natural wood directly into a high-performance structural material with a more than tenfold increase in strength, toughness and ballistic resistance and with greater dimensional stability. Our two-step process involves the partial removal of lignin and hemicellulose from the natural wood via a boiling process in an aqueous mixture of NaOH and Na2SO3 followed by hot-pressing, leading to the total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres. This strategy is shown to be universally effective for various species of wood. Our processed wood has a specific strength higher than that of most structural metals and alloys, making it a low-cost, high-performance, lightweight alternative.

  4. Using wood products to mitigate climate change: External costs and structural change

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, 831 25 Oestersund (Sweden)

    2009-02-15

    In this study we examine the use of wood products as a means to mitigate climate change. We describe the life cycle of wood products including forest growth, wood harvest and processing, and product use and disposal, focusing on the multiple roles of wood as both material and fuel. We present a comparative case study of a building constructed with either a wood or a reinforced concrete frame. We find that the production of wood building material uses less energy and emits less carbon than the production of reinforced concrete material. We compare the relative cost of the two building methods without environmental taxation, under the current Swedish industrial energy taxation regime, and in scenarios that incorporate estimates of the full social cost of carbon emission. We find that the inclusion of climate-related external costs improves the economic standing of wood construction vis-a-vis concrete construction. We conclude that policy instruments that internalise the external costs of carbon emission should encourage a structural change toward the increased use of sustainably produced wood products. (author)

  5. The configuration of residential area in urban structure of the palace in Siak Sri Indrapura - Riau

    Science.gov (United States)

    Rijal, Muhammad

    2018-05-01

    This article is part of major research in describing the configuration of waterfront residential area in urban space structure of the palace and related to the Malay Kingdom in the waterside of the Strait of Malacca. This research aimed to identify the configuration of riverfront residential area in Siak Sri Indrapura City based on physical and non-physical aspects. The method used in this research was qualitative rationalistic referring to the components of urban design theory. The results of the research showed that the spatial configuration in Siak Sri Indrapura City is linear and related to the past events and socio-cultural and socio-economic interaction of the society.

  6. Laminated wood as an alternative to wood poles : Engineered wood structures for electric utility and telecommunications industries

    Energy Technology Data Exchange (ETDEWEB)

    Reisdorff, R. [Laminated Wood Systems Inc., Seward, NE (United States)

    2002-07-01

    In this PowerPoint presentation, the author discusses the major advantages of laminated structures, for both the electric and telecommunication industries. The advantages include economy, quick delivery, climbing and field modifications, dimensional uniformity and stability. A series of pictures was displayed which showed the manufacturing process. Laminated structures have a proven history. They were developed in Europe in 1890, and introduced to the United States in 1934. Framing members were introduced in the late 1940s, while poles were introduced in 1963, two years ahead of steel poles. Some of the electrical utility applications include: (1) distribution structures, (2) transmission structures such as single-pole, phase over phase switch structures, tangent structures, and H-Frame construction. The applications for the telecommunication industry consist of joint use structures, such as electric and telecommunication, lighting and telecommunication, overhead telephone and wireless; mono-pole applications; three-pole Bell Towers; and tree poles. Examples of each type were shown. figs.

  7. Does the structure of wood contribute to understanding the oaks decline phenomenon?

    Directory of Open Access Journals (Sweden)

    Mirela Tulik

    2014-04-01

    Full Text Available Vascular cambium is a meristematic tissue which produces wood centriphugaly and phloem centripetaly. In the structure of wood and phloem, data concerning developmental processes taking place in the cambium is recorded. The history of the cambium is encoded in the dimensions, numbers and arrangements of the wood and phloem cells. For investigations, the wood is usually preferred because it is durable and such data could remain unchanged for centuries, whereas in the phloem due to distorted processes, it deranges after a few years. In broadleaves, the wood is composed of vessels, tracheids, fibers and parenchyma cells. The process of the wood formation consists of the cambial cell derivatives expansion, lignification of its walls and programmed cell death. Since the seventies of the nineteenth century, the process of declining oaks taking place in Europe on a regular basis has been observed. Oak decline is a complex process that involves interactions of both biotic and abiotic factors leading to increased trees mortality. The main goal of the studies is the examination of the structure of wood in declining oaks (Quercus robur L. in respect to physiological (conductive role of this tissue. It is known that on the level of the wood structure, water transport efficiency depends on the diameter of vessels - the main elements of the hydraulic conductivity system. Any reduction of the vessels lumen causes the reduction of the water transport to the organs of the trees body and, therefore, influences organisms survival rate. Anatomical analyses were carried out on wood samples (comprising all annual rings formed during the 30-40 years life of the analyzed trees collected at breast height from the main stem of healthy, weakened and dead oaks. The anatomical traits of the wood like as the width of the annual increments, the diameter and density of early wood vessels were measured. The results which are described in the paper by Tulik (2014 revealed that

  8. NIR monitoring of in-service wood structures

    Science.gov (United States)

    Michela Zanetti; Timothy G. Rials; Douglas Rammer

    2005-01-01

    Near infrared spectroscopy (NIRS) was used to study a set of Southern Yellow Pine boards exposed to natural weathering for different periods of exposure time. This non-destructive spectroscopic technique is a very powerful tool to predict the weathering of wood when used in combination with multivariate analysis (Principal Component Analysis, PCA, and Projection to...

  9. STRUCTURAL ANALYSIS OF WOOD-LEATHER PANELS BY RAMAN SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    Tilman Grünewald,

    2012-02-01

    Full Text Available Besides other ligno-cellulosic materials such as straw, rice husks, or bagasse, wet blue particles from leather production are a promising new raw material stock for wood-based panels, as they offer not only a high availability, but increase the properties of the panel with regard to fire resistance or mechanical characteristics. A panel with a mixture of 42.5% wood fibers, 42.5% wet blue leather particles, and 15% lignin adhesive was produced, and an inhomogeneous sample was prepared. An area of 9 x 10 mm was rasterized and scanned by means of Raman Spectroscopy. Furthermore, the reference spectra of the constituents, i.e. wood fiber, wet blue leather particle, and lignin powder were recorded. The obtained data were treated and analyzed using chemometric methods (principal components analysis PCA and cluster analysis. An important finding was that the reference data were not directly represented in the panels’ spectra, and the correlation matrix of the PCA was not applicable to the panel data. This indicated that chemical changes might take place during the pressing. After processing the panel Raman spectra with the help of PCA and cluster analysis, three distinctive clusters were obtained, discriminating wood, leather, and mixed regions. With the assigned spectral information, it was possible to create a spectral image of the surface.

  10. Development Directions for Various Types of the Light Wood-Framed Structures

    Science.gov (United States)

    Malesza, J.; Baszeń, M.; Miedziałowski, Cz

    2017-11-01

    The paper presents current trends in the development of the wood-framed structures. Authors describe the evolution of the technology of implementation, the production process of precast elements of buildings as well as selected realization on the site of these kinds of structures. The attention has been paid to the effect of implementation phases on construction and erecting technology of the wood-framed structures. The paper draws attention to the importance and enhancement of structural analysis of structures in individual phases of building realization.

  11. Sustainability of Physical Activity Promoting Environments and Influences on Sustainability Following a Structural Intervention in Residential Children's Homes

    Science.gov (United States)

    Dominick, Gregory M.; Tudose, Alina; Pohlig, Ryan T.; Saunders, Ruth P.

    2016-01-01

    Research examining sustainability of health promotion programs within organizational settings is limited. The Environmental Interventions in Residential Children's Homes (ENRICH) was a structural intervention that trained Wellness Teams (WTs) within residential children's homes (RCH) to target environmental changes that promote physical activity…

  12. HIGH RESOLUTION MICROTOMOGRAPHY FOR DENSITY AND SPATIAL INFORMATION ABOUT WOOD STRUCTURES.

    Energy Technology Data Exchange (ETDEWEB)

    ILLMAN,B.

    1999-07-22

    Microtomography has successfully been used to characterize loss of structural integrity of wood. Tomographic images were generated with the newly developed third generation x-ray computed microtomography (XCMT) instrument at the X27A beamline at the National Synchrotron Light Source (NSLS). The beamline is equipped with high-flux x-ray monochromator based on multilayer optics developed for this application. The sample is mounted on a translation stage with which to center the sample rotation, a rotation stage to perform the rotation during data collection and a motorized goniometer head for small alignment motions. The absorption image is recorded by a single-crystal scintillator, an optical microscope and a cooled CCD array detector. Data reconstruction has provided three-dimensional geometry of the heterogeneous wood matrix in microtomographic images. Wood is a heterogeneous material composed of long lignocellulose vessels. Although wood is a strong natural product, fungi have evolved chemical systems that weaken the strength properties of wood by degrading structural vessels. Tomographic images with a resolution of three microns were obtained nonintrusively to characterize the compromised structural integrity of wood. Computational tools developed by Lindquist et al (1996) applied to characterize the microstructure of the tomographic volumes.

  13. Reliability and service life of wood structures and buildings

    Directory of Open Access Journals (Sweden)

    Zdeňka Havířová

    2005-01-01

    Full Text Available Service life of constructions and buildings of wood is dependent on temperature and moisture conditions in layers of the building cladding where the wood framework is built in. Temperature/moisture conditions or the corresponding equilibrium moisture content (EMC of the construction show considerable effects on the functional reliability of the whole building from the viewpoint of mechanical resistance and stability (ER1, energy savings and thermal protection (ER6 and hygiene, health and environment protection (ER3. To ensure the reliability of constructions and buildings for the period of their supposed service life a more profound analysis of constructions is necessary from the aspect of a global thermal/technical evaluation.

  14. Preparation of wood-like structured copper with superhydrophobic properties

    Science.gov (United States)

    Wang, Tianchi; Liu, Guiju; Kong, Jian

    2015-12-01

    Here, we report a method to use natural wood lauan as a template to fabricate superhydrophobic biomorphic copper on a carbon substrate (Cu/C). First, a carbon substrate with the microstructure of lauan was obtained by sintering lauan in an oxygen-free environment. A biomorphic Cu/C material was then obtained by immersing this carbon substrate into a Cu(NO3)2 solution and sintering. Finally, the hydrophobicity of the products obtained was investigated. The Cu/C retained the microstructure of the wood well. It exhibited excellent superhydrophobicity after it was modified with fluorine silane. The water contact angle of this modified Cu/C reached 160°.

  15. Evaluation of methods for the physical characterization of the fine particle emissions from two residential wood combustion appliances

    Science.gov (United States)

    Kinsey, John S.; Kariher, Peter H.; Dong, Yuanji

    The fine particle emissions from a U. S. certified non-catalytic wood stove and a zero-clearance fireplace burning Quercus rubra L. (northern red oak) and Pseudotsuga menziesii (Douglas fir) cordwood each at two different moisture levels were determined. Emission testing was performed using both time-integrated and continuous instrumentation for total particle mass, particle number, particle size distribution, and fixed combustion gases using an atmospheric wind tunnel, full-flow laboratory dilution tunnel, and dilution stack sampler with a comparison made between the three dilution systems and two sampling filter types. The total mass emission factors (EFs) for all dilution systems and filter media are extremely variable ranging from fireplace emissions burning wet oak averaged 11 g kg -1. A substantial number of ultrafine particles in the accumulation size range were also observed during all tests as determined by an Electrical Low Pressure Impactor (ELPI) and Scanning Mobility Particle Sizer. The PM-2.5 (particles ≤2.5 μm in aerodynamic diameter) fractions determined from the ELPI electrometer data ranged from 93 to 98% (mass) depending on appliance type as reported previously by Hays et al. (Aerosol Science, 34, 1061, 2003).

  16. Numerical Study of Focusing Effects of Microwaves inside Wood Due to Timber Ring Structure

    Directory of Open Access Journals (Sweden)

    Rocio Sanchez-Montero

    2018-02-01

    Full Text Available The aim of this study is the detailed calculation of microwave propagation inside raw timber in cylindrical configurations. Two different approaches have been used. The first one uses an exact formulation and analytical approximations in order to explore the electromagnetic field distribution inside dry wood. The introduction of conductivity in the exact model makes it so complex that the equations are unsuitable for analytical manipulation. In order to further explore the effect of moisture in cylindrical wood structures, a full scale numerical simulation using commercial software has been performed. The results show that for microwave frequencies in the 3 GHz range and for typical wood parameters, a cylindrical log behaves as a kind of Fresnel lens. This work has important applications in microwave treatment and sensing of wood.

  17. 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...

  18. Finding the displacement of wood structure in heritage building by 3D laser scanner

    Science.gov (United States)

    Lee, M. C.; Tsai, Y. L.; Wang, R. Z.; Lin, M. L.

    2015-08-01

    Heritage buildings are highly prone to long term damage from the microclimate, scourge and vandalism, which can result in damaged materials, structures, painting and cultural heritage items. This study will focus on finding the displacement of wood structural members through the use of a 3D laser scanner and the 4D concept of time. The results will compare the scans from different periods to find the difference (if any) in the structural member position. Wood structures usually consist of numerous wood members connected to form the structure. However, these members can be damaged in various ways such as physical mechanisms, chemical reactions, and biological corrosion. When damage to the wood structure occurs, the structural displacement can be affected, and if affected severely, can lead to a building collapse. Monitoring of the structural displacement is the best way to discover damage immediately and to preserve the heritage building. However, the Cultural Heritage Preservation Law in Taiwan prohibits the installation of monitoring instruments (e.g strain gauge, accelerometer) in historic structures (heritage buildings). Scanning the wood structure with 3D lasers is the most non-intrusive method and quickly achieves displacement through visualization. The displacement scan results can be compared with different periods and different members to analyze the severity of damage. Once the 3D scanner is installed, the whole building is scanned, and point clouds created to build the visual building model. The structural displacement can be checked via the building model and the differences are measured between each member to find the high risk damaged areas or members with large displacement. Early detection of structural damage is the most effective way means of preservation.

  19. Environmental Assessment: Disposition of Chiefs’ Circle Residential Structures

    Science.gov (United States)

    2012-04-27

    five structures ranged from Page 4 of 5  $200,000 (with bricks removed) to $500,000 (with bricks intact). Mike Ford, CEO of NewTown Macon, echoed Mr...feasibility 25-Jul-08 and practicality of moving the Chief’s Circle duplexes Mike Ford NewTown Macon 23-Jul-08 478-722-9909 President of NewTown Macon...Daniel.Chavira@ Gave a tour of Chiefs’ Circle huntcompanies.com Not interested in using the houses Bob Sharples RAFB 26-Oct-10 robert.sharples

  20. Dynamic modeling of potentially conflicting energy reduction strategies for residential structures in semi-arid climates.

    Science.gov (United States)

    Hester, Nathan; Li, Ke; Schramski, John R; Crittenden, John

    2012-04-30

    Globally, residential energy consumption continues to rise due to a variety of trends such as increasing access to modern appliances, overall population growth, and the overall increase of electricity distribution. Currently, residential energy consumption accounts for approximately one-fifth of total U.S. energy consumption. This research analyzes the effectiveness of a range of energy-saving measures for residential houses in semi-arid climates. These energy-saving measures include: structural insulated panels (SIP) for exterior wall construction, daylight control, increased window area, efficient window glass suitable for the local weather, and several combinations of these. Our model determined that energy consumption is reduced by up to 6.1% when multiple energy savings technologies are combined. In addition, pre-construction technologies (structural insulated panels (SIPs), daylight control, and increased window area) provide roughly 4 times the energy savings when compared to post-construction technologies (window blinds and efficient window glass). The model also illuminated the importance variations in local climate and building configuration; highlighting the site-specific nature of this type of energy consumption quantification for policy and building code considerations. Published by Elsevier Ltd.

  1. Soil food web structure after wood ash application

    DEFF Research Database (Denmark)

    Mortensen, Louise Hindborg; Qin, Jiayi; Cruz-Paredes, Carla

    the consequences of returning wood ash to biofuel producing coniferous forest. We that the change in pH and increased availability of nutrients after ash application to forest floor can facilitate an increase in the bacteria to fungi ratio with possible effects for the soil food by applying ash of different...... concentrations to experimental plots in a coniferous forest the soil will be collected with varying intervals and subsequently analyzed. The food web included several trophic levels; bacteria/fungi, protozoa, nematodes, enchytraeids and microarthropods and arthropods. Results from 2014 indicated that bacteria...... and protozoa were stimulated in the uppermost soil layer (0-3 cm) two months ash application, whereas the enchytraeids seemed to be slightly negatively affected. Generally, nematodes also appeared to be negatively affected, although it differed between feeding groups. On the higher trophic levels, no effect...

  2. The Evolving Market Structure of the U.S. Residential Solar PV Installation Industry, 2000-2016

    Energy Technology Data Exchange (ETDEWEB)

    OShaughnessy, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-02-22

    Market structure refers to the number of firms and the distribution of market shares among firms within an industry. In The Evolving Market Structure of the U.S. Residential Solar PV Installation Industry, 2000-2016, we examine market structure in the context of residential solar PV. We find that over 8,000 companies have installed at least one residential PV system, with about 2,900 companies active in 2016. The majority of residential PV installers are relatively small companies, with about half of installers installing fewer than five systems. At the same time, a subset of high-volume installers accumulated market share, especially beginning around 2010 with the emergence of alternative customer financing options.

  3. Microbial Communities in Sunken Wood Are Structured by Wood-Boring Bivalves and Location in a Submarine Canyon

    Science.gov (United States)

    Fagervold, Sonja K.; Romano, Chiara; Kalenitchenko, Dimitri; Borowski, Christian; Nunes-Jorge, Amandine; Martin, Daniel; Galand, Pierre E.

    2014-01-01

    The cornerstones of sunken wood ecosystems are microorganisms involved in cellulose degradation. These can either be free-living microorganisms in the wood matrix or symbiotic bacteria associated with wood-boring bivalves such as emblematic species of Xylophaga, the most common deep-sea woodborer. Here we use experimentally submerged pine wood, placed in and outside the Mediterranean submarine Blanes Canyon, to compare the microbial communities on the wood, in fecal pellets of Xylophaga spp. and associated with the gills of these animals. Analyses based on tag pyrosequencing of the 16S rRNA bacterial gene showed that sunken wood contained three distinct microbial communities. Wood and pellet communities were different from each other suggesting that Xylophaga spp. create new microbial niches by excreting fecal pellets into their burrows. In turn, gills of Xylophaga spp. contain potential bacterial symbionts, as illustrated by the presence of sequences closely related to symbiotic bacteria found in other wood eating marine invertebrates. Finally, we found that sunken wood communities inside the canyon were different and more diverse than the ones outside the canyon. This finding extends to the microbial world the view that submarine canyons are sites of diverse marine life. PMID:24805961

  4. Structural wood products in onshore buildings at Naval Station Norfolk, 2000.

    Science.gov (United States)

    David B. McKeever

    2003-01-01

    As of December 31, 2000, there were 603 buildings at Naval Station (NAVSTA) Norfolk with a combined floor area of nearly 17.3 million ft2. In one-third of these buildings, structural wood products were used in one or more major structural building applications, utilizing an estimated 11.6 million board feet of lumber, 0.4 million ft2 (3/8-in. basis) of structural...

  5. Wood as inspiration for new stimuli-responsive structures and materials

    Science.gov (United States)

    Joseph E. Jakes; Nayomi Plaza-Rodriguez; Samuel L. Zelinka; Donald S. Stone; Sophie-Charlotte Gleber; Stefan Vogt

    2014-01-01

    Nature has often provided inspiration for new smart structures and materials. Recently, we showed a bundle of a few wood cells are moisture-activated torsional actuators that can reversibly twist multiple revolutions per centimeter of length. The bundles produce specific torque higher than that produced by electric motors and possess shape memory twist capabilities....

  6. Processing bulk natural wood into a high-performance structural material

    Science.gov (United States)

    Jianwei Song; Chaoji Chen; Shuze Zhu; Mingwei Zhu; Jiaqi Dai; Upamanyu Ray; Yiju Li; Yudi Kuang; Yongfeng Li; Nelson Quispe; Yonggang Yao; Amy Gong; Ulrich H. Leiste; Hugh A. Bruck; J. Y. Zhu; Azhar Vellore; Heng Li; Marilyn L. Minus; Zheng Jia; Ashlie Martini; Teng Li; Liangbing Hu

    2018-01-01

    Synthetic structural materials with exceptional mechanical performance suffer from either large weight and adverse environmental impact (for example, steels and alloys) or complex manufacturing processes and thus high cost (for example, polymer-based and biomimetic composites)1–8. Natural wood is a low-cost and abundant material and has been used...

  7. Neighborhood Disadvantage, Residential Segregation, and Beyond-Lessons for Studying Structural Racism and Health.

    Science.gov (United States)

    Riley, Alicia R

    2018-04-01

    A recent surge of interest in identifying the health effects of structural racism has coincided with the ongoing attention to neighborhood effects in both epidemiology and sociology. Mindful of these currents in the literature, it makes sense that we are seeing an emergent tendency in health disparities research to operationalize structural racism as either neighborhood disadvantage or racial residential segregation. This review essay synthesizes findings on the relevance of neighborhood disadvantage and residential segregation to the study of structural racism and health. It then draws on recent literature to propose four lessons for moving beyond traditional neighborhood effects approaches in the study of structural racism and health. These lessons are (1) to shift the focus of research from census tracts to theoretically meaningful units of analysis, (2) to leverage historic and geographic variation in race relations, (3) to combine data from multiple sources, and (4) to challenge normative framing that aims to explain away racial health disparities without discussing racism or racial hierarchy. The author concludes that research on the health effects of structural racism should go beyond traditional neighborhood effects approaches if it is to guide intervention to reduce racial and ethnic health disparities.

  8. Ectomycorrhizal community structure and function in relation to forest residue harvesting and wood ash applications

    International Nuclear Information System (INIS)

    Mahmood, Shahid

    2000-05-01

    Ectomycorrhizal fungi form symbiotic associations with tree roots and assist in nutrient-uptake and -cycling in forest ecosystems, thereby constituting a most significant part of the microbial community. The aims of the studies described in this thesis were to evaluate the potential of DNA-based molecular methods in below-ground ectomycorrhizal community studies and to investigate changes in ectomycorrhizal communities on spruce roots in sites with different N deposition, and in sites subjected to harvesting of forest residues or application of wood ash. The ability of selected ectomycorrhizal fungi to mobilise nutrients from wood ash and to colonise root systems in the presence and absence of ash was also studied. In total 39 ectomycorrhizal species were detected in the experimental forests located in southern Sweden. At each site five to six species colonised around 60% of the root tips. The dominant species, common to the sites, were Tylospora fibrillosa, Thelephora terrestris and Cenococcum geophilum. Differences between two sites with differing levels of N deposition suggested that community structure may be influenced by N deposition, although site history, location and degree of isolation may also influence species composition. Repeated harvesting of forest residues reduced numbers of mycorrhizal roots in the humus layer to approximately 50% of that in control plots but no shift in the ectomycorrhizal community could be detected. At another site, application of granulated wood ash induced a shift in ectomycorrhizal community structure and three ectomycorrhizal fungi ('ash fungi') were found to colonise ash granules. Two 'ash fungi' showed a superior ability to solubilise stabilised wood ash in laboratory experiments compared to other ectomycorrhizal isolates from the same site. In laboratory microcosms containing intact mycorrhizal mycelia, colonisation of wood ash patches by one 'ash fungus' was good whereas colonisation by Piloderma croceum was poor. In a

  9. Multipass comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2014-05-27

    A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction one or more times through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel.

  10. Evaluation of wood structure using GPR with FO method - Effect of moisture, fibers direction and density

    Science.gov (United States)

    Chinh Maï, Tien; Reci, Hamza; Sbartaï, Zoubir Mehdi; Pajewski, Lara; Marciniak, Marian

    2017-04-01

    This work deals with the potential of GPR method in the evaluation of wood structure in relation with density of wood (different wood species), the orientation of fibers and water content (Maï et al., 2015; Reci et al., 2016). The system of measurements is the georadar type (GPR-ground penetrating radar) composed of an electromagnetic signal generator (SIR 3000 of GSSI), and one couple of antennas, one Transmitter (T) and a Receiver (R) of 1.5GHz center frequency, located in the same box in a fixed distance of 6cm. Six wood samples are tested, three samples of Epicea and three samples of Pine. To compare and analyze the results of dielectric constants, we have used the data on three principal directions (Transvesal, Longitudinal and Radial). We note that the dielectric constant of wood increases with the moisture by mass as a consequence of increasing polarization and the conduction phenomena. This effect is more distinguished when the electric field is polarized parallel to the fibers than in perpendicular direction. The smallest contrasts are observed in the radial direction. We conclude that is more appropriate to evaluate the water content along the parallel direction of fibers. In this case we observe the maximum of contrasts of dielectric contrasts between dry and humidity states. Differences on dielectric constant, spectras and amplitudes are taken between different wood samples. Knowing that the dielectric constant is related to the capacity of polarizing (dependent on the water quantity), the increasing of water content could explain the difference of values obtained for the dielectric constants between two kinds of wood. Acknowledgement The Authors are grateful to COST - European Cooperation in Science and Technology (www.cost.eu) for funding the Action TU1208 "Civil engineering applications of Ground Penetrating Radar" (www.GPRadar.eu). We acknowledge also the French National Research Agency (ANR) for supporting this study through the Xylo-plate project

  11. Nature of unresolved complex mixture in size-distributed emissions from residential wood combustion as measured by thermal desorption-gas chromatography-mass spectrometry

    Science.gov (United States)

    Hays, Michael D.; Smith, N. Dean; Dong, Yuanji

    2004-08-01

    Unresolved complex mixture (UCM) is an analytical artifact of gas chromatographs of combustion source-related fine aerosol extracts. In this study the UCM is examined in size-resolved fine aerosol emissions from residential wood combustion. The aerosols are sorted by size in an electrical low-pressure impactor (ELPI) and subsequently analyzed by thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). A semiquantitative system for predicting the branched alkane, cycloalkane, alkylbenzene, C3-, C4-, C5-alkylbenzene, methylnaphthalene, C3-, C4-, C5-alkylnaphthalene, methylphenanthrene C2-, C3-alkylphenanthrene, and dibenzothiophene concentrations in the UCM is introduced. Analysis by TD/GS/MS detects UCM on each ELPI stage for all six combustion tests. The UCM baseline among the different fuel types is variable. In particular, the UCM of Pseudotsuga sp. is enriched in later-eluting compounds of lower volatility. A high level of reproducibility is achieved in determining UCM areas. UCM fractions (UCM ion area/total extracted ion chromatograph area) by individual ELPI stage return a mean relative standard deviation of 19.1% over the entire combustion test set, indicating a highly consistent UCM fraction across the ELPI size boundaries. Among the molecular ions investigated, branched alkane (m/z 57) and dibenzothiophene (m/z 212 and 226) constituents are most abundant in UCM emissions from RWC, collectively accounting for 64-95% of the targeted chemical species. The total UCM emissions span 446-756 mg/kg of dry biomass burned and correspond to an upper limit of 7.1% of the PM2.5 mass. The UCM emissions are primarily accumulation mode (0.1 μm ≤ aerodynamic diameter (da) ≤ 1 μm), with a geometric mean diameter (dg) range of 120.3-518.4 nm. UCM in PM2.5 is chemically asymmetric (shifted to finer da), typically clustering at da ≤ 1 μm. Measurable shifts in dg and changes in distribution widths (σg) on an intratest basis suggest that the particle density

  12. Laminated composite based on polyester geotextile fibers and polyurethane resin for coating wood structures

    OpenAIRE

    Assagra,Yuri Andrey Olivato; Altafim,Ruy Alberto Pisani; Silva,José Francisco Resende da; Basso,Heitor Cury; Lahr,Francisco Antonio Rocco; Altafim,Ruy Alberto Corrêa

    2013-01-01

    New environmental laws have restricted the use of hardwood trees in overhead power lines structures, such as, poles and cross-arms, leading companies to seek alternative materials. Reforested wood coated with polymeric resin has been proposed as an environmental friendly solution, with improved electrical properties and protection against external agents, e.g. moisture, ultraviolet radiation and fungi. However, the single thin layer of resin, normally applied on such structures reveal to be i...

  13. Laminated composite based on polyester geotextile fibers and polyurethane resin for coating wood structures

    Directory of Open Access Journals (Sweden)

    Yuri Andrey Olivato Assagra

    2013-01-01

    Full Text Available New environmental laws have restricted the use of hardwood trees in overhead power lines structures, such as, poles and cross-arms, leading companies to seek alternative materials. Reforested wood coated with polymeric resin has been proposed as an environmental friendly solution, with improved electrical properties and protection against external agents, e.g. moisture, ultraviolet radiation and fungi. However, the single thin layer of resin, normally applied on such structures reveal to be inefficient, due to be easily damage during handling. In this paper, we present a composite coating, based on geotextile fibers and polyurethane resin that is suitable for wooden structures. Results obtained from two different tree species (from managed and reforested areas coated with the composite reveal that the additional layer not only provided a stronger adhesion between wood and ccoating layer but also a further improvement in the electrical properties and better protection against abrasion and moisture.

  14. Study of structural capacity and serviceability affecting the obstruction of residential door

    Directory of Open Access Journals (Sweden)

    Eric Forcael

    Full Text Available The last Chilean earthquake, occurred on February 27, 2010, allowed establishing important patterns of structural failures in reinforced concrete residential buildings; however, limited progress has been made in the study of basic standards of serviceability, such as obstruction of doors. Thus, this study focused on measuring the influence of design specifications and construction criteria of lintels and columns, in terms of obstruction of doors, considering capacity thresholds for certain levels of displacement. The study consisted of the design and construction of a full-scale prototype of a reinforced concrete frame, designed in accordance with all the ACI-318-08 requirements, taking into account typical aspects of geometry and materiality widely used by the real estate industry, for location and size of doors. In order to quantify the structural capacity of the prototype and to study the serviceability of the door, a quasi-static cyclic test was conducted, according to load and displacement protocols specified in FEMA 356 and FEMA 461, which was adjusted by using virtual models based on a static nonlinear analysis called "Pushover". This research verified that, for displacement levels even five times higher than those established by codes considered, the cracking degree was minimal and fully recoverable. It was also found the door evidenced malfunction when the displacements were greater than those specified by design only, validating a high degree of accomplishment of current codes, in terms of capacity and serviceability, when dealing with obstruction of residential doors.

  15. 2006 : Wood Products Used in New Residential Construction U.S. and Canada, with Comparisons to 1995, 1998 and 2003 : Executive Summary

    Science.gov (United States)

    Craig Adair; David B. McKeever

    2009-01-01

    The construction of new single family, multifamily, and manufactured housing is an important market for wood products in both the United States and Canada. Annual wood products consumption is dependent on many factors, including the number of new units started, the size of units started, architectural characteristics, and consumer preferences. In 2006, about 39 percent...

  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. 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.

  18. Comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-08-13

    A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel, wherein the cutting discs have a uniform thickness (T.sub.D), and wherein at least one of L.sub.C, W.sub.C, and H.sub.C is greater than T.sub.D.

  19. Soil food web structure after wood ash application

    DEFF Research Database (Denmark)

    Mortensen, L. H.; Qin, J.; Krogh, Paul Henning

    with varying intervals and subsequently analyzed. The food web analysis includes several trophic levels; bacteria/fungi, protozoa, nematodes, enchytraeids, microarthropods and arthropods. The initial results indicate that bacteria and protozoa are stimulated in the uppermost soil layer (0-3 cm) two months...... can facilitate an increase in the bacteria to fungi ratio with possible cascading effects for the soil food web structure. This is tested by applying ash of different concentrations to experimental plots in a coniferous forest. During the course of the project soil samples will be collected...

  20. Wood digestion in Pselactus spadix Herbst--a weevil attacking marine timber structures.

    Science.gov (United States)

    Oevering, Pascal; Pitman, Andrew J; Pandey, Krishna K

    2003-04-01

    Pselactus spadix tunnels timber structures in the marine environment. Recent studies reported a cosmopolitan distribution for this weevil, which is frequently found in harbour and port areas. P. spadix feeds on timber (hardwood and softwood) in immature and adult life stages, but its digestion of wood components had not been investigated. Using dry weight analyses of tunnel walls and frass produced, P. spadix adults consumed Scots pine with soft rot decay at a rate of 1.59 +/- 0.37 mg d-1 and the digestibility of this substrate was 57.96 +/- 5.89 (i.e. for 100 mg consumed SR-pine, 58 mg was digested). Using gravimetric analysis to quantify structural wood components in tunnel walls and frass, P. spadix adults were found to digest cellulose, lignin and hemicellulose with digestibility coefficients of 82.2, 41.2 and 14.5 respectively. Fourier Transform Infrared (FTIR) spectroscopy analyses of tunnel walls and frass of adults and larvae from soft rotted pine also indicated digestion of all structural components, with larvae digesting cellulose and lignin more efficiently than adults. When FTIR was employed to analyse adult tunnel walls and frass from undecayed pine, cellulose and hemicellulose were digested, but no evidence of lignin digestion was found. This study shows that adults digest lignin when soft rot is present and suggests a symbiotic function of wood degrading microorganisms.

  1. Field assessment of the impacts of landscape structure on different-sized airborne particles in residential areas of Beijing, China

    Science.gov (United States)

    Fan, Shuxin; Li, Xiaopeng; Han, Jing; Cao, Yu; Dong, Li

    2017-10-01

    In high-density metropolis, residential areas are important human living environments. Aimed at investigating the impacts of landscape structure on the levels of different-sized airborne particle in residential areas, we conducted field monitoring of the levels of TSP, PM10, PM2.5 and PM1 using mobile traverses in 18 residential areas during the daytime in winter (Dec. 2015-Feb. 2016) and summer (Jun.-Aug. 2016) in Beijing, China. The net concentration differences (d) of the four-sized particles (dTSP, dPM10, dPM2.5 and dPM1) between residential environments and nearby corresponding urban backgrounds, which can be regarded as the reduction of particle concentration in residential environments, were calculated. The effects and relative contributions of different landscape structure parameters on these net concentration differences were further investigated. Results showed that the distribution of particle concentrations has great spatial variation in urban environments. Within the residential environment, there were overall lower concentrations of the four-sized particles compared with the nearby urban background. The net concentration differences of the four-sized particles were all significantly different among the 18 studied residential areas. The average dTSP, dPM10, dPM2.5 and dPM1 reached 18.92, 12.28, 2.01 and 0.53 μg/m3 in summer, and 9.91, 7.81, 1.39 and 0.38 μg/m3 in winter, respectively. The impacts and relative contribution of different landscape structure parameters on the reductions of TSP, PM10, PM2.5 and PM1 in residential environments differed and showed seasonal variation. Percentage of vegetation cover (PerVC) and building cover (PerBC) had the greatest impact. A 10% increase in PerVC would increase about 5.03, 8.15, 2.16 and 0.20 μg/m3 of dTSP, dPM10, dPM2.5 and dPM1 in summer, and a 10% increase in PerBC would decreased about 41.37, 16.54, 2.47 and 0.95 μg/m3 of them in winter. Increased vegetation coverage and decreased building

  2. Structural and optical properties of wood and wood finishes studied using optical coherence tomography: application to an 18th century Italian violin.

    Science.gov (United States)

    Latour, Gaël; Echard, Jean-Philippe; Soulier, Balthazar; Emond, Isabelle; Vaiedelich, Stéphane; Elias, Mady

    2009-11-20

    Optical coherence tomography (OCT) is especially attractive for the study of cultural heritage artifacts because it is noninvasive and nondestructive. We have developed an original full-field time-domain OCT system dedicated to the investigation of varnished and painted artifacts: an interferometric Mirau objective allows one to perform the scan without moving the works of art. The axial and transverse high resolution (respectively, 1.5 and 1 microm) are well adapted to the detection of the investigated structures (pigment grains, wood fibers, etc.). The illumination spectrum is in the visible range (centered at 630 nm, 150 nm wide) to potentially allow us to perform spectroscopic OCT on pigment particles. The examination of wood samples coated with a traditional finish, demonstrates the ability of the system to detect particles, characterize layers thickness, and image the three-dimensional wood structures below the varnishes. OCT has finally been applied to study in situ the coated wood surface of an 18th century Italian violin and provides important information for its conservation treatment.

  3. Ectomycorrhizal community structure and function in relation to forest residue harvesting and wood ash applications

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, Shahid

    2000-05-01

    Ectomycorrhizal fungi form symbiotic associations with tree roots and assist in nutrient-uptake and -cycling in forest ecosystems, thereby constituting a most significant part of the microbial community. The aims of the studies described in this thesis were to evaluate the potential of DNA-based molecular methods in below-ground ectomycorrhizal community studies and to investigate changes in ectomycorrhizal communities on spruce roots in sites with different N deposition, and in sites subjected to harvesting of forest residues or application of wood ash. The ability of selected ectomycorrhizal fungi to mobilise nutrients from wood ash and to colonise root systems in the presence and absence of ash was also studied. In total 39 ectomycorrhizal species were detected in the experimental forests located in southern Sweden. At each site five to six species colonised around 60% of the root tips. The dominant species, common to the sites, were Tylospora fibrillosa, Thelephora terrestris and Cenococcum geophilum. Differences between two sites with differing levels of N deposition suggested that community structure may be influenced by N deposition, although site history, location and degree of isolation may also influence species composition. Repeated harvesting of forest residues reduced numbers of mycorrhizal roots in the humus layer to approximately 50% of that in control plots but no shift in the ectomycorrhizal community could be detected. At another site, application of granulated wood ash induced a shift in ectomycorrhizal community structure and three ectomycorrhizal fungi ('ash fungi') were found to colonise ash granules. Two 'ash fungi' showed a superior ability to solubilise stabilised wood ash in laboratory experiments compared to other ectomycorrhizal isolates from the same site. In laboratory microcosms containing intact mycorrhizal mycelia, colonisation of wood ash patches by one 'ash fungus' was good whereas colonisation by

  4. How the user can influence particulate emissions from residential wood and pellet stoves: Emission factors for different fuels and burning conditions

    Science.gov (United States)

    Fachinger, Friederike; Drewnick, Frank; Gieré, Reto; Borrmann, Stephan

    2017-06-01

    For a common household wood stove and a pellet stove we investigated the dependence of emission factors for various gaseous and particulate pollutants on burning phase, burning condition, and fuel. Ideal and non-ideal burning conditions (dried wood, under- and overload, small logs, logs with bark, excess air) were used. We tested 11 hardwood species (apple, ash, bangkirai, birch, beech, cherry, hickory, oak, olive, plum, sugar maple), 4 softwood species (Douglas fir, pine, spruce, spruce/fir), treated softwood, beech and oak wood briquettes, paper briquettes, brown coal, wood chips, and herbaceous species (miscanthus, Chinese silver grass) as fuel. Particle composition (black carbon, non-refractory, and some semi-refractory species) was measured continuously. Repeatability was shown to be better for the pellet stove than for the wood stove. It was shown that the user has a strong influence on wood stove emission behavior both by selection of the fuel and of the burning conditions: Combustion efficiency was found to be low at both very low and very high burn rates, and influenced particle properties such as particle number, mass, and organic content in a complex way. No marked differences were found for the emissions from different wood species. For non-woody fuels, much higher emission factors could be observed (up to five-fold increase). Strongest enhancement of emission factors was found for burning of small or dried logs (up to six-fold), and usage of excess air (two- to three-fold). Real world pellet stove emissions can be expected to be much closer to laboratory-derived emission factors than wood stove emissions, due to lower dependence on user operation.

  5. 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...

  6. Dielectric study on hierarchical water structures restricted in cement and wood materials

    International Nuclear Information System (INIS)

    Abe, Fumiya; Nishi, Akihiro; Saito, Hironobu; Asano, Megumi; Watanabe, Seiei; Kita, Rio; Shinyashiki, Naoki; Yagihara, Shin; Fukuzaki, Minoru; Sudo, Seiichi; Suzuki, Youki

    2017-01-01

    Dielectric relaxation processes for mortar observed by broadband dielectric spectroscopy were analyzed in the drying and hydration processes for an aging sample in the frequency region from 1 MHz up to 2 MHz. At least two processes for structured water in the kHz frequency region and another mHz relaxation process affected by ionic behaviors were observed. Comparison of the relaxation parameters obtained for the drying and hydration processes suggests an existence of hierarchical water structures in the exchange of water molecules, which are originally exchanged from free water observed at around 20 GHz. The water molecules reflected in the lower frequency process of the two kHz relaxation processes are more restricted and take more homogeneous structures than the higher kHz relaxation process. These structured water usually hidden in large ionic behaviors for wood samples was observed by electrodes covered by a thin Teflon film, and hierarchical water structures were also suggested for wood samples. Dielectric spectroscopy technique is an effective tool to analyze the new concept of hierarchical water structures in complex materials. (paper)

  7. The Evolving Market Structure of the U.S. Residential Solar PV Installation Industry, 2000-2016

    Energy Technology Data Exchange (ETDEWEB)

    OShaughnessy, Eric J. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2018-01-16

    This study uses data on over 900,000 solar PV installations to summarize the evolving market structure of the U.S. residential solar PV installation industry. Over 8,000 companies have installed residential PV systems in the United States. The vast majority of these installers are small local companies. At the same time, a subset of national-scale high-volume PV installation companies hold high market shares. This study examines the factors behind these trends in market concentration, including the role of customer financing options.

  8. Do homes that are more energy efficient consume less energy?: A structural equation model of the English residential sector

    International Nuclear Information System (INIS)

    Kelly, Scott

    2011-01-01

    Energy consumption from the residential sector is a complex socio-technical problem that can be explained using a combination of physical, demographic and behavioural characteristics of a dwelling and its occupants. A structural equation model (SEM) is introduced to calculate the magnitude and significance of explanatory variables on residential energy consumption. The benefit of this approach is that it explains the complex relationships that exist between manifest variables and their overall effect though direct, indirect and total effects. Using the English House Condition Survey (EHCS) consisting of 2531 unique cases, the main drivers behind residential energy consumption are found to be the number of household occupants, floor area, household income, dwelling efficiency (SAP), household heating patterns and living room temperature. In the multivariate case, SAP explains very little of the variance of residential energy consumption. However, this procedure fails to account for simultaneity bias between energy consumption and SAP. Using SEM its shown that dwelling energy efficiency (SAP), has reciprocal causality with dwelling energy consumption and the magnitude of these two effects are calculable. When non-recursivity between SAP and energy consumption is allowed for, SAP is shown to have a negative effect on energy consumption but conversely, homes with a propensity to consume more energy also have higher SAP rates. -- Highlights: → A Structural Equation Model (SEM) is developed to explain residential energy demand. → Key variables that drive residential energy consumption are empirically identified. → Direct, indirect and total effects are determined. → It is found that occupancy and household income are strongly mediated by floor area. → A non-recursive relationship is found to exist between energy consumption and SAP.

  9. Analysis of U.S. household wood energy consumption: 1967-2009

    Science.gov (United States)

    Nianfu. Song; Francisco X. Aguilar; Stephen R. Shifley; Michael E. Goerndt

    2012-01-01

    The residential sector consumes about 23% of the energy derived from wood (wood energy) in the U.S. An estimated error correction model with data from 1967 to 2009 suggests that residential wood energy consumption has declined by an average 3% per year in response to technological progress, urbanization, accessibility of non-wood energy, and other factors associated...

  10. The pellet wood gasification boiler - a modern and environment-friendly alternative for energy generation in the residential section. 3. rev. ed; Scheitholzvergaserkessel - eine moderne und umweltfreundliche Alternative fuer die Energieerzeugung im haeuslichen Bereich

    Energy Technology Data Exchange (ETDEWEB)

    Uth, J.

    2001-12-01

    The decision to install a pellet wood gasification boiler is a conscious vote using renewable fuels in the residential sector. This brochure has been elaborated to facilitate interested citizens the right selection of this boilers. So an effective evaluation of the listed boiler types is possible. Text and tables are based on a manufacturers questionnaire, taking place from 1995 to September 1999respectively in October 2000 due to a fast technological development were actualized. Furthermore new sellers appeared upgrading their product spectra in the heating sector by advanced wood gasification boilers.(GL) [German] Die Entscheidung zur Installation eines Scheitholzvergaserkessels ist ein bewusstes Votum zum Einsatz eines nachwachsenden Brennstoffes im haeuslichen Bereich. Um ineressierten Buergern die Auswahl geeigneter Kessel zu erleichtern, wurde die vorliegende Broschuere ausgearbeitet. Damit ist eine effektive Beurteilung der aufgelisteten Kesseltypen moeglich. Text und Tabellen basieren auf einer Herstellerumfrage aus dem Jahr 1995, die im September 1999 bzw. im Oktober 2000 auf grund der rasanten technischen Entwicklung dieses Sektors aktualisiert werden musste. Darueber hinaus sind gaenzlich neue Anbieter aufgetreten, die ihre Produktpalette im Heizungsbereich mit modernen Scheitholzvergaserkesseln aufwerten wollen (Pflege des ''Oekoimage'').(orig/GL)

  11. Structural Risk Assessment and Mitigation for Low- to Mid-Rise Residential Buildings in China

    Directory of Open Access Journals (Sweden)

    Kasim A. Korkmaz

    2017-07-01

    Full Text Available China has experienced major earthquakes recently. The 2014 Ludian earthquake struck Ludian County, Yunnan, (Mw = 6.1 on 3 August, 2014. On April 20th 2013, Ya’an earthquake (Mw = 6.9, on April 14th 2010, Qinghai earthquake (Mw = 7.1, on July 9th 2009, Yunnan earthquake (Mw = 6.0, and on May 12th 2008, Sichuan earthquake (Mw = 7.9 struck China. Among these disasters, the most devastating, the Sichuan earthquake, resulted in the collapse of 5 million buildings and damage to more than 21 million. Human loss was also high with over 60,000 people dead, 360,000 injured, and more than 14 million people displaced. South-west China lies in an area that is prone to earthquakes. In 1970, a magnitude 7.7 earthquake in Yunnan with 15,000 lost. This study presents a detailed risk assessment for a structural risk assessment and mitigation for low- to mid-rise residential buildings for China. The risk assessment, through seismic hazard assessment approaches, evaluates the impact of the disasters for integrated structural health monitoring. Among the results of the investigation, relations and links between safety and risk are defined.

  12. Residential energy use in Mexico: Structure, evolution, environmental impacts, and savings potential

    Energy Technology Data Exchange (ETDEWEB)

    Masera, O.; Friedmann, R.; deBuen, O.

    1993-05-01

    This article examines the characteristics of residential energy use in Mexico, its environmental impacts, and the savings potential of the major end-uses. The main options and barriers to increase the efficiency of energy use are discussed. The energy analysis is based on a disaggregation of residential energy use by end-uses. The dynamics of the evolution of the residential energy sector during the past 20 years are also addressed when the information is available. Major areas for research and for innovative decision-making are identified and prioritized.

  13. A supramolecular proposal of lignin structure and its relation with the wood properties

    Directory of Open Access Journals (Sweden)

    Heber S. Abreu

    2009-03-01

    Full Text Available In spite of the great importance of cellulose the lignin is considered the second most abundant substance of the wood. However, little attention has been given it, mainly to wood properties. The lignin as well as other structural compounds (cellulose and hemicelluloses, has obviously an important role on the wood properties, probably due its composition and existent bonds. In general lignins have β-O-4 (Alkyl Aril Ether as majoritary bond. This bond in a continued structure form big molecules with spiral conformation as virtual model. Based on this idea, lignins that have high/low β-O-4 content may have differentiated spiraled structures,suggesting different behaviors on the wood properties,which shows that the lignins (Guaicyl:Syringyl (GS of angiosperms, for example, which have higher β-O-4 content would present higher spiral conformation than gymnosperms lignins(HG. On the other hand HG lignins have chance of being more anchored on the matrix compound than GS lignins. In this context, the β-O-4 bonds of lignins possibly affect the wood properties, therefore, it is considered relevant for wood technology science discussion.Apesar da grande importância da celulose a lignina é considerada a segunda substância mais abundante da madeira. Entretanto, pouca atenção tem sido dada a ela, principalmente com relação às propriedades da madeira. A lignina assim como outras substâncias (celulose e hemicelulose, tem obviamente um papel importante sobre as propriedades da madeira, provavelmente devido a sua composição e a existências de ligações. Geralmente as ligninas possuem majoritariamente ligaçõesβ-O-4 (Éter Alquil-Arílico, esta ligação em uma estrutura contínua forma grandes moléculas com conformação em espiral, como visto em modelo virtual. Com base nesta idéia, ligninas que possuem alto/baixo teor de β-O-4, podem ter estruturas espiraladas diferenciadas, sugerindo comportamentos diferentes sobre as propriedades da

  14. Stand structure and dead wood characterization in cork forest of Calabria region (southern Italy

    Directory of Open Access Journals (Sweden)

    Barreca L

    2010-07-01

    Full Text Available The cork forests are one the most interesting forest ecosystems in the Mediterranean area. Their distribution and ecological characteristics have undergone a significant transformation after the significant changes following the development and establishment of agricultural crops. Currently, only a few stands, which survive in hard to reach places, prove the wide spread distribution of this species was also in the recent past. This study describes the stand structure of some cork forests in Calabria region (southern Italy. In order, to characterize the vertical structure Latham index has been applied, while for the description of the horizontal distribution NBSI group indices has been used. Detailed surveys on dead wood were also conducted determining the occurring volume and its decay stage according to the decay classes system proposed by Hunter. The aim of this study is to provide guidelines for sustainable management of cork forests, improving and promoting the structural complexity and functional efficiency of these forest stands.

  15. WOOD STOVE EMISSIONS: PARTICLE SIZE AND CHEMICAL COMPOSITION

    Science.gov (United States)

    The report summarizes wood stove particle size and chemical composition data gathered to date. [NOTE: In 1995, EPA estimated that residential wood combustion (RWC), including fireplaces, accounted for a significant fraction of national particulate matter with aerodynamic diameter...

  16. 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...

  17. Impact of performance interdependencies on structural vulnerability: A systems perspective of storm surge risk to coastal residential communities

    International Nuclear Information System (INIS)

    Hatzikyriakou, Adam; Lin, Ning

    2017-01-01

    Interaction between residential structures during natural hazards can lead to interdependencies in their performance. During storm surge, for example, structures can affect the performance of inland buildings by generating damaging waterborne debris or by beneficially dampening surge loads. Quantifying the impact of this interaction on structural vulnerability is critical for risk assessment and informed decision-making. In this study we present and implement two general modeling approaches for investigating such interdependencies. The first method is to condition the vulnerability of a structure on the performance of neighboring buildings using a Markov model. The second uses a marginal model to account for correlation between damage observations when estimating a structure's vulnerability to the hazard. Both approaches are implemented using a case study of an impacted coastal community during Hurricane Sandy (2012). Findings indicate that a structure's performance during storm surge is strongly dependent on the damage state of the structure immediately seaward. Furthermore, considering the correlated damage states of buildings increases statistical uncertainty when relating structural performance to hazard intensity. Motivated by these findings, we propose a more coordinated approach to coastal risk mitigation which considers the effects of interdependencies on insurance pricing, structural design, mitigation strategies and community resilience. - Highlights: • Interaction between residential structures leads to performance interdependencies. • Interdependencies during storm surge are due to debris and structural shielding. • Markov model treats interdependencies as an additional demand parameter. • Marginal model incorporates damage correlation into regression estimation. • System behavior should be considered in community risk and resilience.

  18. 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....

  19. 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)

  20. The effects of habitat degradation on metacommunity structure of wood-inhabiting fungi in European beech forests

    DEFF Research Database (Denmark)

    Halme, Panu; Ódor, Péter; Christensen, Morten

    2013-01-01

    Intensive forest management creates habitat degradation by reducing the variation of forest stands in general, and by removing old trees and dead wood in particular. Non-intervention forest reserves are commonly believed to be the most efficient tool to counteract the negative effects...... with different management histories. For this purpose, we used a large data set of wood-inhabiting fungi collected from dead beech trees in European beech-dominated forest reserves. The structure of fungal assemblages showed high beta diversity, while nestedness and similarity was low. During the decomposition...... extirpated specialized species from the local species pools in managed sites, and resulted in more homogeneous communities in managed sites. It is alarming that community structure is affected the most in the latest decay stages where the decay process turns the dead wood into litter, and which is thus...

  1. Flood loss modelling with FLF-IT: a new flood loss function for Italian residential structures

    Science.gov (United States)

    Hasanzadeh Nafari, Roozbeh; Amadio, Mattia; Ngo, Tuan; Mysiak, Jaroslav

    2017-07-01

    The damage triggered by different flood events costs the Italian economy millions of euros each year. This cost is likely to increase in the future due to climate variability and economic development. In order to avoid or reduce such significant financial losses, risk management requires tools which can provide a reliable estimate of potential flood impacts across the country. Flood loss functions are an internationally accepted method for estimating physical flood damage in urban areas. In this study, we derived a new flood loss function for Italian residential structures (FLF-IT), on the basis of empirical damage data collected from a recent flood event in the region of Emilia-Romagna. The function was developed based on a new Australian approach (FLFA), which represents the confidence limits that exist around the parameterized functional depth-damage relationship. After model calibration, the performance of the model was validated for the prediction of loss ratios and absolute damage values. It was also contrasted with an uncalibrated relative model with frequent usage in Europe. In this regard, a three-fold cross-validation procedure was carried out over the empirical sample to measure the range of uncertainty from the actual damage data. The predictive capability has also been studied for some sub-classes of water depth. The validation procedure shows that the newly derived function performs well (no bias and only 10 % mean absolute error), especially when the water depth is high. Results of these validation tests illustrate the importance of model calibration. The advantages of the FLF-IT model over other Italian models include calibration with empirical data, consideration of the epistemic uncertainty of data, and the ability to change parameters based on building practices across Italy.

  2. Flood loss modelling with FLF-IT: a new flood loss function for Italian residential structures

    Directory of Open Access Journals (Sweden)

    R. Hasanzadeh Nafari

    2017-07-01

    Full Text Available The damage triggered by different flood events costs the Italian economy millions of euros each year. This cost is likely to increase in the future due to climate variability and economic development. In order to avoid or reduce such significant financial losses, risk management requires tools which can provide a reliable estimate of potential flood impacts across the country. Flood loss functions are an internationally accepted method for estimating physical flood damage in urban areas. In this study, we derived a new flood loss function for Italian residential structures (FLF-IT, on the basis of empirical damage data collected from a recent flood event in the region of Emilia-Romagna. The function was developed based on a new Australian approach (FLFA, which represents the confidence limits that exist around the parameterized functional depth–damage relationship. After model calibration, the performance of the model was validated for the prediction of loss ratios and absolute damage values. It was also contrasted with an uncalibrated relative model with frequent usage in Europe. In this regard, a three-fold cross-validation procedure was carried out over the empirical sample to measure the range of uncertainty from the actual damage data. The predictive capability has also been studied for some sub-classes of water depth. The validation procedure shows that the newly derived function performs well (no bias and only 10 % mean absolute error, especially when the water depth is high. Results of these validation tests illustrate the importance of model calibration. The advantages of the FLF-IT model over other Italian models include calibration with empirical data, consideration of the epistemic uncertainty of data, and the ability to change parameters based on building practices across Italy.

  3. Quantitative Structure Activity Relationship of Cinnamaldehyde Compounds against Wood-Decaying Fungi

    Directory of Open Access Journals (Sweden)

    Dongmei Yang

    2016-11-01

    Full Text Available Cinnamaldehyde, of the genius Cinnamomum, is a major constituent of the bark of the cinnamon tree and possesses broad-spectrum antimicrobial activity. In this study, we used best multiple linear regression (BMLR to develop quantitative structure activity relationship (QSAR models for cinnamaldehyde derivatives against wood-decaying fungi Trametes versicolor and Gloeophyllun trabeum. Based on the two optimal QSAR models, we then designed and synthesized two novel cinnamaldehyde compounds. The QSAR models exhibited good correlation coefficients: R2Tv = 0.910 for Trametes versicolor and R2Gt = 0.926 for Gloeophyllun trabeum. Small errors between the experimental and calculated values of two designed compounds indicated that these two QSAR models have strong predictability and stability.

  4. Polygyny and strong genetic structuring within an isolated population of the wood ant Formica rufa

    Directory of Open Access Journals (Sweden)

    Wouter Dekoninck

    2014-12-01

    Full Text Available Social structuring of populations within some Formica species exhibits considerable variation going from monodomous and monogynous populations to polydomous, polygynous populations. The wood ant species Formica rufa appears to be mainly monodomous and monogynous throughout most of its distribution area in central and northern Europe. Only occasionally it was mentioned that F. rufa can have both polygynous and monogynous colonies in the same geographical region. We studied an isolated polydomous F. rufa population in a deciduous mixed forest in the north-west of Belgium. The level of polydomy within the colonies varied from monodomous to 11 nests per colony. Our genetic analysis of eight variable microsatellites suggest an oligo- to polygynous structure for at least the major part of the sampled nests. Relatedness amongst nest mate workers varies considerable within the population and colonies but confirms in general a polygynous structure. Additionally high genetic diversity (e.g. up to 8 out of 11 alleles per nest for the most variable locus and high within nest genetic variance (93% indicate that multiple queens contribute to the gene pool of workers of the same nest. Moreover significant genetic structuring among colonies indicates that gene flow between colonies is restricted and that exchange of workers between colonies is very limited. Finally we explain how possible factors as budding and the absence of Serviformica can explain the differences in genetic structure within this polygynous F. rufa population.

  5. Health effects assessment of exposure to particles from wood smoke

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Elsa; Dybdahl, M [Technical Univ. of Denmark, National Food Institute, Dept. of Toxicology and Risk Assessment, Soeborg (Denmark); Larsen, Poul Bo [Danish Environmental Protection Agency, Copenhagen (Denmark)

    2008-07-01

    The number of residential wood burning devices has increased in Denmark during the latest years and it has been estimated that there in 2005 were about 551,000 wood stoves and about 48,000 wood boilers in Denmark. This has resulted in an increased exposure of the general Danish population to pollutants associated with residential wood smoke. New Danish monitoring results on particulate matter (PM) in ambient air have shown elevated PM levels in areas with many wood stoves, particularly during wintertime when wood burning is common. Due to the size distribution of wood smoke particles essentially all will be contained in the PM{sub 2.5} fraction. It has been estimated that about 17,665 tonnes PM{sub 2.5} per year (2005) in Denmark come from residential wood combustion. Therefore, there is an increasing concern that adverse human health effects might be associated with the increased exposure to residential wood smoke. This project has been set up in order to review the scientific literature concerning adverse health effects of pollutants associated with residential wood smoke with the main focus on particulate matter and to quantify and evaluate, if possible, the impact on human health of the increased exposure to particles in residential wood smoke. (au)

  6. Orthogonal model and experimental data for analyzing wood-fiber-based tri-axial ribbed structural panels in bending

    Science.gov (United States)

    Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

    2017-01-01

    This paper presents an analysis of 3-dimensional engineered structural panels (3DESP) made from wood-fiber-based laminated paper composites. Since the existing models for calculating the mechanical behavior of core configurations within sandwich panels are very complex, a new simplified orthogonal model (SOM) using an equivalent element has been developed. This model...

  7. Particle-bound reactive oxygen species (PB-ROS) emissions and formation pathways in residential wood smoke under different combustion and aging conditions

    Science.gov (United States)

    Zhou, Jun; Zotter, Peter; Bruns, Emily A.; Stefenelli, Giulia; Bhattu, Deepika; Brown, Samuel; Bertrand, Amelie; Marchand, Nicolas; Lamkaddam, Houssni; Slowik, Jay G.; Prévôt, André S. H.; Baltensperger, Urs; Nussbaumer, Thomas; El-Haddad, Imad; Dommen, Josef

    2018-05-01

    Wood combustion emissions can induce oxidative stress in the human respiratory tract by reactive oxygen species (ROS) in the aerosol particles, which are emitted either directly or formed through oxidation in the atmosphere. To improve our understanding of the particle-bound ROS (PB-ROS) generation potential of wood combustion emissions, a suite of smog chamber (SC) and potential aerosol mass (PAM) chamber experiments were conducted under well-determined conditions for different combustion devices and technologies, different fuel types, operation methods, combustion regimes, combustion phases, and aging conditions. The PB-ROS content and the chemical properties of the aerosols were quantified by a novel ROS analyzer using the DCFH (2',7'-dichlorofluorescin) assay and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). For all eight combustion devices tested, primary PB-ROS concentrations substantially increased upon aging. The level of primary and aged PB-ROS emission factors (EFROS) were dominated by the combustion device (within different combustion technologies) and to a greater extent by the combustion regimes: the variability within one device was much higher than the variability of EFROS from different devices. Aged EFROS under bad combustion conditions were ˜ 2-80 times higher than under optimum combustion conditions. EFROS from automatically operated combustion devices were on average 1 order of magnitude lower than those from manually operated devices, which indicates that automatic combustion devices operated at optimum conditions to achieve near-complete combustion should be employed to minimize PB-ROS emissions. The use of an electrostatic precipitator decreased the primary and aged ROS emissions by a factor of ˜ 1.5 which is however still within the burn-to-burn variability. The parameters controlling the PB-ROS formation in secondary organic aerosol were investigated by employing a regression model, including the fractions of

  8. Signatures of self-assembly in size distributions of wood members in dam structures of Castor canadensis

    Directory of Open Access Journals (Sweden)

    David M. Blersch

    2014-12-01

    Full Text Available Beavers (Castor canadensis construct dams on rivers throughout most of their historical range in North America, and their impact on water patterns in the landscape is considerable. Dam formation by beavers involves two processes: (1 intentional construction through the selection and placement of wood and sediment, which facilitates (2 the passive capture and accretion of suspended wood and sediment. The second process is a self-assembly mechanism that the beavers leverage by utilizing energy subsidies of watershed transport processes. The relative proportion of beaver activity to self-assembly processes in dam construction, however, is unknown. Here we show that lotic self-assembly processes account for a substantial portion of the work expended in beaver dam construction. We found through comprehensive measurement of the stick dimensions that the distributions for diameter, length, and volume are log-normal. By noting evidence of teeth markings, we determined that size distributions skewed significantly larger for wood handled by beavers compared to those that were not. Subsequent mass calculations suggest that beavers perform 50%–70% of the work of wood member placement for dam assembly, with riparian self-assembly processes contributing the remainder. Additionally, our results establish a benchmark for assessing the proportion of self-assembly work in similar riparian structures. Keywords: Beaver dam, Construction, Castor canadensis, Self-assembly, Distribution, Wood

  9. Combined assessment of the environmental, economic and social impacts of structural solutions for residential construction

    Directory of Open Access Journals (Sweden)

    Fraile-García, E.

    2015-09-01

    Full Text Available Sustainable development in construction is based on three fundamental pillars: economic, environmental and social. This type of approach aims to identify the best possible solutions for sustainably developing structures by conducting a joint evaluation of the impact on those three pillars. The proposed methodology incorporates metadata on the Spanish construction sector. First, a discrete database is generated with 360 alternatives covering a range of common solutions in residential building. A Pareto algorithm is utilized to select the optimal choices and the wide range of solutions is reduced to the 5 % of the initial group. The project manager is therefore provided with an objective assessment of suitable structural alternatives including the overall joint economic, social, and environmental impact. The results obtained demonstrate the importance and utility of the proposed methodology for sustainable construction.El desarrollo sostenible aplicado a la construcción se basa en tres pilares fundamentales: económico, medioambiental y social. El objetivo principal es identificar las mejores soluciones en términos de desarrollo sostenible de alternativas estructurales a partir de la evaluación conjunta de los impactos en dichos pilares. La metodología propuesta incorpora metadatos con información del sector de la construcción en España. Primero se genera una base de datos discreta de 360 alternativas estructurales que cubren el rango de soluciones habituales en edificación residencial. La selección de alternativas óptimas se realiza mediante el algoritmo de Pareto. El abanico de soluciones se reduce al 5 % de las iniciales. Se aporta una valoración objetiva que orienta al proyectista en la selección de alternativas estructurales idóneas, visualizando de forma conjunta el impacto económico, social y ambiental. Los resultados obtenidos muestran la importancia y utilidad de la metodología propuesta en el campo de la construcci

  10. Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures.

    Science.gov (United States)

    Dickson, E D; Hamby, D M

    2014-03-01

    The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building's radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology.

  11. Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures

    International Nuclear Information System (INIS)

    Dickson, E D; Hamby, D M

    2014-01-01

    The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building’s radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology. (paper)

  12. 24 CFR 40.2 - Definition of “residential structure”.

    Science.gov (United States)

    2010-04-01

    ... OWNED RESIDENTIAL STRUCTURES § 40.2 Definition of “residential structure”. (a) As used in this part, the term residential structure means a residential structure (other than a privately owned residential structure and a residential structure on a military reservation): (1) Constructed or altered by or on behalf...

  13. Models for predicting turnover of residential aged care nurses: a structural equation modelling analysis of secondary data.

    Science.gov (United States)

    Gao, Fengsong; Newcombe, Peter; Tilse, Cheryl; Wilson, Jill; Tuckett, Anthony

    2014-09-01

    Nurse turnover in the residential aged care industry is a pressing issue. Researchers have shown ongoing interest in exploring how the factors that are amendable to change in aged care policy, regulation and funding and in organizational procedures (e.g. job demands, coping resources and psychological health of nurses) impact on turnover. However, the findings are mixed. This study tested two theoretical models of turnover to examine the structural relationships among job demands, coping resources, psychological health and turnover of residential aged care nurses. Although many previous studies operationalized turnover as intention to leave, the present study investigated actual turnover by following up with the same individuals over time, and thus provided more accurate predictive models of turnover behaviour. The sample, 239 Australian residential aged care nurses, came from the Nurses and Midwives e-cohort Study. Job demands, coping resources, and psychological health were measured using standardized instruments. Structural equation modelling was used to test the measurement and structural models. Controlling for a number of workforce and individual characteristics, coping resources (measured by job control, supervisor support, and co-worker support) were negatively and directly associated with turnover. Additionally, the findings supported the Job Demand-Control-Support model in that higher coping resources and lower job demands (indicated by psychological demands, physical demands, and effort) were related to better psychological health (measured by vitality, social functioning, role emotional, and mental health), and higher job demands were related to lower coping resources. Findings suggest that aged care policy makers and service providers might consider increasing coping resources available to nurses and minimizing job demands of care work to reduce turnover and improve nurses' psychological health. Moreover, findings from this Australian study may provide

  14. 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.

  15. Feedbacks between earlywood anatomy and non-structural carbohydrates affect spring phenology and wood production in ring-porous oaks

    Science.gov (United States)

    Pérez-de-Lis, Gonzalo; García-González, Ignacio; Rozas, Vicente; Olano, José Miguel

    2016-10-01

    Non-structural carbohydrates (NSC) play a central role in the construction and maintenance of a tree's vascular system, but feedbacks between the NSC status of trees and wood formation are not fully understood. We aimed to evaluate multiple dependencies among wood anatomy, winter NSC, and phenology for coexisting temperate (Quercus robur) and sub-Mediterranean (Q. pyrenaica) oaks along a water-availability gradient in the NW Iberian Peninsula. Sapwood NSC concentrations were quantified at three sites in December 2012 (N = 240). Leaf phenology and wood anatomy were surveyed in 2013. Structural equation modelling was used to analyse the interplay among hydraulic diameter (Dh), winter NSC, budburst date, and earlywood vessel production (EVP), while the effect of Dh and EVP on latewood width was assessed by using a mixed-effects model. NSC and wood production increased under drier conditions for both species. Q. robur showed a narrower Dh and lower soluble sugar (SS) concentration (3.88-5.08 % dry matter) than Q. pyrenaica (4.06-5.57 % dry matter), but Q. robur exhibited larger EVP and wider latewood (1403 µm) than Q. pyrenaica (667 µm). Stem diameter and Dh had a positive effect on SS concentrations, which were related to an earlier leaf flushing in both species. Sapwood sugar content appeared to limit EVP exclusively in Q. pyrenaica. In turn, Dh and EVP were found to be key predictors of latewood growth. Our results confirm that sapwood SS concentrations are involved in modulating growth resumption and xylem production in spring. Q. pyrenaica exhibited a tighter control of carbohydrate allocation to wood formation than Q. robur, which would play a role in protecting against environmental stress in the sub-Mediterranean area.

  16. Chinese wood frame buildings and the changing dimensions of their structural components in different time periods

    Directory of Open Access Journals (Sweden)

    Nujaba Binte Kabir

    2012-06-01

    Full Text Available The Features of the Chinese wood frame buildings are same in character from dynasty to dynasty. The study concentrates on 9 Chinese wood frame buildings from Tang to Yuan dynasty and tries to relate these buildings with the text described in a building manual book published in Song dynasty Yingzao fashi. The features of some buildings match with the text described in the book some do not. But on the other hand Liang Sicheng, scholar of Chinese architecture in his book claimed that Chinese wood frame architecture has a unique system of characteristics (Liang, 1984. The system of wood frame Chinese architecture did not change but the proportion of the features has changed in different dynasty. The aim of the paper is to compare the features of the buildings those have been studied according to Yingzao fashi with Liang's observation on the change of building style in different periods.

  17. Structural Concept and Analysis of a 17-Story Multifunctional Residential Complex with and without Seismic Isolation System

    International Nuclear Information System (INIS)

    Melkumyan, Mikayel; Gevorgyan, Emma

    2008-01-01

    In recent years seismic isolation technologies in Armenia were extensively applied in construction of multistory buildings. These are 10-17-story residential complexes with parking floors and with floors envisaged for offices, shopping centers, fitness clubs, etc. Also there is a 20-story business centre designed in 2006, which is currently under construction. All mentioned complexes are briefly described in the paper, which is, however, mainly dedicated to the 17-story residential complex designed in 2007. The structural concept, including the new approach on installation of seismic isolation rubber bearings in this building, is described and detailed results of the earthquake response analysis for two cases, i.e. when the building is base isolated and when it has a fixed base, are given. Several time histories were used in the analysis and for both cases the building was analyzed also according to the requirements of the Armenian Seismic Code. Comparison of the obtained results indicates the high effectiveness of the proposed structural concept of isolation system and the need for further improvement of Seismic Code provisions regarding the values of the reduction factors

  18. The impact of co-combustion of polyethylene plastics and wood in a small residential boiler on emissions of gaseous pollutants, particulate matter, PAHs and 1,3,5- triphenylbenzene.

    Science.gov (United States)

    Tomsej, Tomas; Horak, Jiri; Tomsejova, Sarka; Krpec, Kamil; Klanova, Jana; Dej, Milan; Hopan, Frantisek

    2018-04-01

    The aim of this study was to simulate a banned but widely spread practice of co-combustion of plastic with wood in a small residential boiler and to quantify its impact on emissions of gaseous pollutants, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and 1,3,5-triphenylbenzene (135TPB), a new tracer of polyethylene plastic combustion. Supermarket polyethylene shopping bags (PE) and polyethylene terephthalate bottles (PET) were burnt as supplementary fuels with beech logs (BL) in an old-type 20 kW over-fire boiler both at a nominal and reduced heat output. An impact of co-combustion was more pronounced at the nominal heat output: an increase in emissions of PM, total organic carbon (TOC), toxic equivalent (TEQ) of 7 carcinogenic PAHs (c-PAHs) and a higher ratio of c-PAHs TEQ in particulate phase was observed during co-combustion of both plastics. 135TPB was found in emissions from both plastics both at a nominal and reduced output. In contrast to findings reported in the literature, 135TPB was a dominant compound detected by mass spectrometry on m/z 306 exclusively in emissions from co-combustion of PE. Surprisingly, six other even more abundant compounds of unknown identity were found on this m/z in emissions from co-combustion of PET. One of these unknown compounds was identified as p-quaterphenyl (pQ). Principal component analysis revealed strong correlation among 135TPB, pQ and five unknown compounds. pQ seems to be suitable tracers of polyethylene terephthalate plastic co-combustion, while 135TPB proved its suitability to be an all-purpose tracer of polyethylene plastics combustion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Structures and electrochemical properties of pyrolytic carbon films infiltrated from gas phase into electro-conductive substrates derived from wood

    International Nuclear Information System (INIS)

    Ohzawa, Yoshimi; Mitani, Masami; Li, Jianling; Nakajima, Tsuyoshi

    2004-01-01

    Using the pressure-pulsed chemical vapor infiltration technique, pyrolytic carbon (pyrocarbon) films were deposited into two sorts of conductive porous substrates, that is, the carbonized wood (A) and the TiN-coated wood (B). Structures and electrochemical properties were investigated as the negative electrodes of lithium-ion secondary battery. The electrodes had the three-dimensionally continuous current paths in the pyrocarbon-based anodes without the organic binders and the additional conductive fillers. The pyrocarbon films adhered tightly to the carbonized wood or TiN as current collector. These macro-structures of electrodes were effective in improving the high rate property. The sort of substrates affected the nano-structure of pyrocarbon. The pyrocarbon in sample (A) had the relatively high crystallinity, whereas the pyrocarbon in sample (B) was disordered. The capacity of pyrocarbon in sample (B) was higher than that of sample (A), reflecting the disordered microstructure of pyrocarbon film (B). However, sample (A) showed higher Coulombic efficiency at first cycle (i.e. 87%) than that of sample (B), which would result from the high crystallinity, laminar microstructure and low surface area of pyrocarbon in sample (A)

  20. 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…

  1. 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)

  2. 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.

  3. 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.

  4. Enzymatic saccharification and structural properties of industrial wood sawdust: Recycled ionic liquids pretreatments

    International Nuclear Information System (INIS)

    Auxenfans, Thomas; Buchoux, Sébastien; Larcher, Dominique; Husson, Gérard; Husson, Eric; Sarazin, Catherine

    2014-01-01

    Highlights: • 1-Ethyl-3-metylimidazolium acetate is an effective catalyst for pretreatment of hardwood and softwood sawdust. • Regeneration of cellulosic fraction from ionic liquid is discussed. • 1-Ethyl-3-methylimidazolium acetate can be reused at least 7 times without loss of its efficiency. • Removal of extractives and lignin with slight cellulose and xylan losses were observed. • Better cellulase accessibility to cellulose thanks to the expansion of the powder and the creation of a large porous volume. - Abstract: Wood residues constitute a promising challenge for biochemical processing into bioethanol and chemicals with competitive costs. Here, we report the impacts of pretreatments in a hydrophilic ionic liquid ([C2mim][OAc]), onto the physicochemical properties and enzymatic saccharification of softwood (spruce) and hardwood (oak) sawdust. Enzymatic saccharification of IL- pretreated sawdust is significantly increased (up to 7 times) when compared to untreated ones. Methanol, ethanol or water can be used as polar anti-solvent for the recovery of a cellulose rich fraction after dissolution in IL (i.e regeneration step) without any effect on enzymatic saccharification. Chemical, textural and structural modifications possibly induced by the IL pretreatments have been investigated through various means (Infra-red spectroscopy, NMR, X-ray diffraction) in order to correlate the observed modifications in enzymatic saccharification. This mild pretreatment seemed to mainly act in a breakdown of lignocellulosic organization leading to better cellulase accessibility to cellulose thanks to the expansion of the powder and the creation of a large porous volume (5 times more apparent porous volume). Partial removal of lignin and extractives may also contribute to the best enzymatic performances. The recyclability and reuse up to 7 times of [C2mim][OAc] is shown without the need of strictly anhydrous conditions and any alteration of the pretreatment

  5. Species associations overwhelm abiotic conditions to dictate the structure and function of wood-decay fungal communities.

    Science.gov (United States)

    Maynard, Daniel S; Covey, Kristofer R; Crowther, Thomas W; Sokol, Noah W; Morrison, Eric W; Frey, Serita D; van Diepen, Linda T A; Bradford, Mark A

    2018-04-01

    Environmental conditions exert strong controls on the activity of saprotrophic microbes, yet abiotic factors often fail to adequately predict wood decomposition rates across broad spatial scales. Given that species interactions can have significant positive and negative effects on wood-decay fungal activity, one possibility is that biotic processes serve as the primary controls on community function, with abiotic controls emerging only after species associations are accounted for. Here we explore this hypothesis in a factorial field warming- and nitrogen-addition experiment by examining relationships among wood decomposition rates, fungal activity, and fungal community structure. We show that functional outcomes and community structure are largely unrelated to abiotic conditions, with microsite and plot-level abiotic variables explaining at most 19% of the total variability in decomposition and fungal activity, and 2% of the variability in richness and evenness. In contrast, taxonomic richness, evenness, and species associations (i.e., co-occurrence patterns) exhibited strong relationships with community function, accounting for 52% of the variation in decomposition rates and 73% in fungal activity. A greater proportion of positive vs. negative species associations in a community was linked to strong declines in decomposition rates and richness. Evenness emerged as a key mediator between richness and function, with highly even communities exhibiting a positive richness-function relationship and uneven communities exhibiting a negative or null response. These results suggest that community-assembly processes and species interactions are important controls on the function of wood-decay fungal communities, ultimately overwhelming substantial differences in abiotic conditions. © 2018 by the Ecological Society of America.

  6. 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.

  7. Residential Care

    Science.gov (United States)

    ... Kids For Teens For Parents & Teachers Resolving Family Conflicts The Holidays and Alzheimer's Glossary Virtual Library Online ... longer an option Costs Choosing a care setting Types of residential care A good long-term care ...

  8. Hydraulic and mechanical properties of young Norway spruce clones related to growth and wood structure

    Science.gov (United States)

    ROSNER, SABINE; KLEIN, ANDREA; MÜLLER, ULRICH; KARLSSON, BO

    2011-01-01

    Summary Stem segments of eight five-year-old Norway spruce (Picea abies (L.) Karst.) clones differing in growth characteristics were tested for maximum specific hydraulic conductivity (ks100), vulnerability to cavitation and behavior under mechanical stress. The vulnerability of the clones to cavitation was assessed by measuring the applied air pressure required to cause 12 and 50% loss of conductivity (Ψ12, Ψ50) and the percent loss of conductivity at 4 MPa applied air pressure (PLC4MPa). The bending strength and stiffness and the axial compression strength and stiffness of the same stem segments were measured to characterize wood mechanical properties. Growth ring width, wood density, latewood percentage, lumen diameter, cell wall thickness, tracheid length and pit dimensions of earlywood cells, spiral grain and microfibril angles were examined to identify structure–function relationships. High ks100 was strongly and positively related to spiral grain angle, which corresponded positively to tracheid length and pit dimensions. Spiral grain may reduce flow resistance of the bordered pits of the first earlywood tracheids, which are characterized by rounded tips and an equal distribution of pits along the entire length. Wood density was unrelated to hydraulic vulnerability parameters. Traits associated with higher hydraulic vulnerability were long tracheids, high latewood percentage and thick earlywood cell walls. The positive relationship between earlywood cell wall thickness and vulnerability to cavitation suggest that air seeding through the margo of bordered pits may occur in earlywood. There was a positive phenotypic and genotypic relationship between ks100 and PLC4MPa, and both parameters were positively related to tree growth rate. Variability in mechanical properties depended mostly on wood density, but also on the amount of compression wood. Accordingly, hydraulic conductivity and mechanical strength or stiffness showed no tradeoff. PMID:17472942

  9. 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...

  10. Re-thinking residential mobility

    Science.gov (United States)

    van Ham, Maarten; Findlay, Allan M.

    2015-01-01

    While researchers are increasingly re-conceptualizing international migration, far less attention has been devoted to re-thinking short-distance residential mobility and immobility. In this paper we harness the life course approach to propose a new conceptual framework for residential mobility research. We contend that residential mobility and immobility should be re-conceptualized as relational practices that link lives through time and space while connecting people to structural conditions. Re-thinking and re-assessing residential mobility by exploiting new developments in longitudinal analysis will allow geographers to understand, critique and address pressing societal challenges. PMID:27330243

  11. 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.

  12. 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).

  13. Homogenization of vegetation structure across residential neighborhoods: effects of climate, urban morphology, and socio-economics

    Science.gov (United States)

    Climate is a key driver regulating vegetation structure across rural ecosystems. In urban ecosystems, multiple interactions between humans and the environment can have homogenizing influences, confounding the relationship between vegetation structure and climate. In fact, vegetat...

  14. Wood decay by brown-rot fungi : changes in pore structure and cell wall volume

    Science.gov (United States)

    Douglas S. Flournoy; T. Kent Kirk; T.L. Highley

    1991-01-01

    Sweetgum (Liquidambar styraciflua L.) wood blocks were decayed by Postia (= Poria) placenta in soilblock cultures. Decay was terminated at various weight losses, and the pore volumes available to four low molecular weight molecules, (water, 4 Å,; glucose, 8 Å,; maltose, 10 Å; and raffinose, 128,) and three dextrans (Mr 6,000, 38 Å; 11,200, 51 Å; nd 17,500, 61 Å) were...

  15. Wood Anatomical Structure of Morus alba L. and Morus nigra L., Native to Iran

    Directory of Open Access Journals (Sweden)

    Elham KARAMI

    2010-12-01

    Full Text Available Iran is a wast country with many different tree species. Among those there are two species of Morus genus including alba and nigra. Since long time ago, white mulberry�s wood (Morus alba has been used for making musical instruments especially bowl shaped instruments in Iran.. In contrast, black mulberry�s wood (Morus nigra has never been used for these types of applications. In order to investigate the possible replacement choices, this study has been carried out to investigate the anatomical differences and similarities between these two species. Wood samples of the two species have been collected from same site and microsections for light microscopic studies and maceration samples have been prepared. The anatomical characteristics were studied according to the IAWA List of Hardwoods. The most important similarities between them are: vessel solitary in short radial multiples or irregular clusters, fiber nonseptate, rays uniseriate and multiseriate type, paratracheal parenchyma, varying from vasicentric to aliform confluent, apotracheal as marginal bands, Rhombic crystals present in rays and sometimes in parenchyma. The main differences are: semi-ring porous distribution of vessels in M. alba, fewer number of vessels and presence of aliform parenchyma in M. nigra. Taking these results into consideration, the most important features of both species are similar and it could be recommended to use the nigra species as well as the alba for making musical instruments.

  16. Effect of Different Heat Treatment Temperatures on the Chemical Composition and Structure of Chinese Fir Wood

    Directory of Open Access Journals (Sweden)

    Shichao Cheng

    2016-03-01

    Full Text Available The properties of wood can be improved after heat-treatment. There have been many studies dealing with mechanical properties and chemical modifications of heat-treated wood. The purpose of this paper is to provide a new analysis method, to give better insights on the hemicelluloses, cellulose, and lignin contents of heat-treated wood by using Fourier transform infrared (FT-IR and two-dimensional infrared (2D-IR spectroscopies. The FT-IR spectra results showed progressive degradation in the carbonyl groups of the glucuronic acid units and degradation of the pyranose of hemicelluloses. These changes were measured as the percentage decrease of crystalline cellulose and the loss of C=O and C=C groups linking together the aromatic skeleton of lignin. The 2D-IR spectra showed the appearance of 5 × 5 peak clusters in the 1000 to 1200 cm-1 region, which could account for the hemicellulose degradation. In addition, changes in the degree of sensitivity at 1627 and 1509 cm-1 coincided with cross-linking reactions among the aromatic units in the lignin molecules.

  17. Statistical process control for residential treated wood

    Science.gov (United States)

    Patricia K. Lebow; Timothy M. Young; Stan Lebow

    2017-01-01

    This paper is the first stage of a study that attempts to improve the process of manufacturing treated lumber through the use of statistical process control (SPC). Analysis of industrial and auditing agency data sets revealed there are differences between the industry and agency probability density functions (pdf) for normalized retention data. Resampling of batches of...

  18. Residential Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde; Matsufuji, Y.

    2011-01-01

    are discussed in this chapter. Characterizing residential waste is faced with the problem that many residences already divert some waste away from the official collection systems, for example performing home composting of vegetable waste and garden waste, having their bundled newspaper picked up by the scouts...... twice a year or bringing their used furniture to the flea markets organized by charity clubs. Thus, much of the data available on residential waste represents collected waste and not necessarily all generated waste. The latter can only be characterized by careful studies directly at the source......, but such studies are very expensive if fair representation of both spatial and temporal variations should be obtained. In addition, onsite studies may affect the waste generation in the residence because of the increased focus on the issue. Residential waste is defined in different ways in different countries...

  19. The role of defensible space for residential structure protection during wildfires

    Science.gov (United States)

    Syphard, Alexandra D.; Brennan, Teresa J.; Keeley, Jon E.

    2014-01-01

    With the potential for worsening fire conditions, discussion is escalating over how to best reduce effects on urban communities. A widely supported strategy is the creation of defensible space immediately surrounding homes and other structures. Although state and local governments publish specific guidelines and requirements, there is little empirical evidence to suggest how much vegetation modification is needed to provide significant benefits. We analysed the role of defensible space by mapping and measuring a suite of variables on modern pre-fire aerial photography for 1000 destroyed and 1000 surviving structures for all fires where homes burned from 2001 to 2010 in San Diego County, CA, USA. Structures were more likely to survive a fire with defensible space immediately adjacent to them. The most effective treatment distance varied between 5 and 20 m (16–58 ft) from the structure, but distances larger than 30 m (100 ft) did not provide additional protection, even for structures located on steep slopes. The most effective actions were reducing woody cover up to 40% immediately adjacent to structures and ensuring that vegetation does not overhang or touch the structure. Multiple-regression models showed landscape-scale factors, including low housing density and distances to major roads, were more important in explaining structure destruction. The best long-term solution will involve a suite of prevention measures that include defensible space as well as building design approach, community education and proactive land use planning that limits exposure to fire.

  20. Leadership and Registered Nurses (RNs) working after-hours in Residential Aged Care Facilities (RACFs): A structured literature review.

    Science.gov (United States)

    Nhongo, Dorika; Hendricks, Joyce; Bradshaw, Julie; Bail, Kasia

    2018-06-12

    Registered nurses (RNs) working in Residential Aged Care Facilities are required to undertake complex management tasks including leading nursing care teams, supervising non-nursing staff, and allocating workloads according to residents' care needs, staff skills and experience. Registered nurses plan, assess, manage medication, evaluate each resident's care, liaise with doctors and allied health professionals and are responsible for evidence-based practice in accordance with the Nursing Standards for Practice (2016). Researchers have commented that effective nurse leadership can improve quality of care, improved resident outcomes and reduce adverse events. The aim of this literature review is to synthesise and analyse the literature pertinent to the RN's competence and confidence to undertake the leadership role when working in residential aged care facilities after-hours and to determine any association of leadership with quality resident outcomes. A review of original research papers based on the structured methodology described by Kable, Pich and Maslin-Prothero (2012). The review was conducted according to the 12-step structured framework by Kable et al. (2012). The search included peer-reviewed papers published between 2002 and 2017 on RN leadership after-hours, factors contributing to or with relationships to nursing leadership. Nineteen papers were found that researched the impact of leadership in aged care settings. The literature review concluded that nursing leadership has been linked to the quality of care and clinical outcomes in the aged care setting. However, RNs in the aged care setting have limited opportunities to develop key leadership competencies and confidence in order to meet the many challenges found in this environment due to lack of access to aged-care-specific leadership education. Minimal publications address the importance of the leadership of after-hours RNs. Results from this literature review will inform future research in this area

  1. Residential fuelwood consumption in the southeastern U.S

    International Nuclear Information System (INIS)

    Christiansen, E.H.; Larsen, M.D.; Rejda, Karen; Bliss, J.C.; Nepal, S.K.

    1993-01-01

    A telephone survey of households in 13 states in the southeastern U.S. determined residential fuelwood acquisition and use for heating during the 1991 heating season. Although wood burning accounted for only 10% of the total household heat requirement of the region, it accounted for 51% of the total heat requirements of wood-burning households. One-quarter (25%) of the households burned wood, consuming almost 9 million standard cords. Three-quarters (77%) of wood-burning households reported that wood burning contributed to household heating requirements. Wood as a source of home heating was particularly important to low income households, both rural and urban. Wood is the sole source of home heating for 17% of the wood-burning households in the regions. (Author)

  2. Isoprenoid-substituted flavonoids from wood of Artocarpus heterophyllus on B16 melanoma cells: cytotoxicity and structural criteria.

    Science.gov (United States)

    Arung, Enos Tangke; Yoshikawa, Keisuke; Shimizu, Kuniyoshi; Kondo, Ryuichiro

    2010-03-01

    As a result of cytotoxicity-guided fractionation, nine flavonoids, artocarpin (1), cudraflavone C (2), 6-prenylapigenin (3), kuwanon C (4), norartocarpin (5), albanin A (6), cudraflavone B (7), brosimone I (8) and artocarpanone (9) were identified from the methanol extract of the wood of Artocarpus heterophyllus, known commonly as Nangka in Indonesia. A structure-activity investigation of the effect of these isolated compounds (1-9) and structurally related compounds on B16 melanoma cells indicated that isoprenoid moiety substitutions in flavonoids enhance their cytotoxicity, and that the position of attachment and the number of isoprenoid-substituent moieties per molecule influence flavonoid cytotoxicity. 2009 Elsevier B.V. All rights reserved.

  3. Mechanical and chemical properties of CCA-treated lumber removed from spent residential decks

    Science.gov (United States)

    Robert L. Smith; David Bailey; Philip A. Araman

    2007-01-01

    The amount of chromated copper arsenate (CCA)- treated wood being removed from spent residential decks is increasing at a tremendous rate. While most spent CCA-treated wood is being disposed in landfills, further useful and environmentally beneficial alternatives have to be met. If the volume of CCA-treated wood reaching landfills continues to rise, stricter disposal...

  4. Changes in residential, occupational and gender structure of the greater Bangkok in the globalization process

    Directory of Open Access Journals (Sweden)

    Satoshi Nakagawa

    2004-12-01

    Full Text Available This study investigated recent changes in migration and population structure of the Greater Bangkok considering the impact of economic globalization. The spatial policy of the Thai government has lead newer investments for manufacturing to locate away from Bangkok Metropolis and thereby the industrial structure of Bangkok Metropolis has gradually turned into service-dominated, while the region surrounding Bangkok Metropolis has attracted factories mainly owned by foreign capital. Light industry and electronics industry are con-centrated in the adjacent provinces to Bangkok Metropolis and the heavy and petrochemical industry tends to be located in the outer zone of the surrounding region. The service sector and light industry as well as electronics industry prefer female workers and Bangkok met-ropolis and the adjoining provinces have become female-dominated population structure while male workers tend to gather in the outer zone attracted by heavy and petrochemical industry. It is possible to mention accordingly that the unbalanced spatial distribution of sex structure of population which might cause changes in the norm to the family formation in future is one of the consequences of economic globalization of Thailand, which the inves-tment promotion policy of the government did not assume.

  5. 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

  6. Bond Performance and Structural Characterization of Polysaccharide Wood Adhesive Made from Konjac Glucomannan/Chitosan/Polyvinyl Alcohol

    Directory of Open Access Journals (Sweden)

    Rong Gu

    2016-08-01

    Full Text Available The bond performance and bonding mechanism were evaluated for a Konjac glucomannan (KGM, Chitosan (CS, and polyvinyl alcohol (PVOH blended wood adhesive. An optimized experimental strategy was used to investigate the effects of the formula parameters of adhesives on the bonding strength of plywood using a Box-Behnken design and response surface methodology (RSM. The microstructure of the blended adhesives was analyzed by Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM. An optimum bonding strength (3.42 ± 0.31 MPa was achieved with concentrations of KGM, CS, and 10% PVOH of 2.3%, 2.3%, and 5.0%, respectively. There was strong hydrogen bonding between the KGM, CS, and 10% PVOH adhesives and the interface. SEM observations indicated that the blended adhesive exhibited a net-like structure that increased the overall bonding strength. These results provided the scientific basis for the continual development of environmentally friendly wood adhesives and the improvement of processing conditions.

  7. 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 (...

  8. Changes in residential, occupational and gender structure of the greater Bangkok in the globalization process

    Directory of Open Access Journals (Sweden)

    Satoshi Nakagawa

    2004-01-01

    Full Text Available This study investigated recent changes in migration and population structure of the GreaterBangkok considering the impact of economic globalization. The spatial policy of the Thaigovernment has lead newer investments for manufacturing to locate away from BangkokMetropolis and thereby the industrial structure of Bangkok Metropolis has gradually turnedinto service-dominated, while the region surrounding Bangkok Metropolis has attractedfactories mainly owned by foreign capital. Light industry and electronics industry are concentratedin the adjacent provinces to Bangkok Metropolis and the heavy and petrochemicalindustry tends to be located in the outer zone of the surrounding region. The service sectorand light industry as well as electronics industry prefer female workers and Bangkok metropolisand the adjoining provinces have become female-dominated population structurewhile male workers tend to gather in the outer zone attracted by heavy and petrochemicalindustry. It is possible to mention accordingly that the unbalanced spatial distribution of sexstructure of population which might cause changes in the norm to the family formation infuture is one of the consequences of economic globalization of Thailand, which the investmentpromotion policy of the government did not assume.

  9. 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).

  10. 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.

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

    International Nuclear Information System (INIS)

    Nussbaumer, T.

    2002-01-01

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

  12. Structure of a fragment of Atlantic Rainforest in regeneration with occurrence of Caesalpinia echinata Lam. (brazil-wood

    Directory of Open Access Journals (Sweden)

    Liliane Baldan Zani

    2012-11-01

    Full Text Available This study aimed to evaluate the phytosociological structure of a remaining fragment of Atlantic Rainforest undergoing regeneration in the town of Aracruz-ES in a forest board with natural occurrence of Caesalpinia echinata Lam. We installed 10 sample units (plots of 10 x 50m, sampling all individuals with DBH≥5cm and <10cm. Altogether, we sampled 500 individuals distributed into 181 species. The richest families were Leguminosae (35, Sapotaceae (18, and Myrtaceae (14. The most important species were Caesalpinia echinata Lam., Eugenia tinguyensis Cambess., and Pterocarpus rohrii Vahl. The Shannon index (H’ was 4.89 and the equability (J’ was 0.94. This area is one of the last remaining fragments with brazil-wood from the state of Espirito Santo and the population of this species is well preserved at the site, it occurs very frequently, emphasizing the importance of preserving small forest fragments to conserve biodiversity.

  13. 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...

  14. Bacterial community structures in air conditioners installed in Japanese residential buildings.

    Science.gov (United States)

    Hatayama, Kouta; Oikawa, Yurika; Ito, Hiroyuki

    2018-01-01

    The bacterial community structures in four Japanese split-type air conditioners were analyzed using a next-generation sequencer. A variety of bacteria were detected in the air filter of an air conditioner installed on the first floor. In the evaporator of this air conditioner, bacteria belonging to the genus Methylobacterium, or the family of Sphingomonadaceae, were predominantly detected. On the other hand, the majority of bacteria detected in the air filters and evaporators of air conditioners installed on the fifth and twelfth floors belonged to the family Enterobacteriaceae. The source of bacteria belonging to the family Enterobacteriaceae may have been aerosols generated by toilet flushing in the buildings. Our results suggested the possibility that the bacterial contamination in the air conditioners was affected by the floor level on which they were installed. The air conditioner installed on the lower floor, near the ground, may have been contaminated by a variety of outdoor bacteria, whereas the air conditioners installed on floors more distant from the ground may have been less contaminated by outdoor bacteria. However, these suppositions may apply only to the specific split-type air conditioners that we analyzed, because our sample size was small.

  15. 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...

  16. Wood structural differences between northern and southern beech provenances growing at a moderate site.

    Science.gov (United States)

    Eilmann, B; Sterck, F; Wegner, L; de Vries, S M G; von Arx, G; Mohren, G M J; den Ouden, J; Sass-Klaassen, U

    2014-08-01

    Planting provenances originating from southern to northern locations has been discussed as a strategy to speed up species migration and mitigate negative effects of climate change on forest stability and productivity. Especially for drought-susceptible species such as European beech (Fagus sylvatica L.), the introduction of drought-tolerant provenances from the south could be an option. Yet, beech has been found to respond plastically to environmental conditions, suggesting that the climate on the plantation site might be more important for tree growth than the genetic predisposition of potentially drought-adapted provenances. In this study, we compared the radial growth, wood-anatomical traits and leaf phenology of four beech provenances originating from southern (Bulgaria, France) and northern locations (Sweden, the Netherlands) and planted in a provenance trial in the Netherlands. The distribution of precipitation largely differs between the sites of origin. The northern provenances experience a maximum and the southern provenances experience a minimum of rainfall in summer. We compared tree productivity and the anatomy of the water-conducting system for the period from 2000 to 2010, including the drought year 2003. In addition, tree mortality and the timing of leaf unfolding in spring were analysed for the years 2001, 2007 and 2012. Comparison of these traits in the four beech provenances indicates the influence of genetic predisposition and local environmental factors on the performance of these provenances under moderate site conditions. Variation in radial growth was controlled by environment, although the growth level slightly differed due to genetic background. The Bulgarian provenance had an efficient water-conducting system which was moreover unaffected by the drought in 2003, pointing to a high ability of this provenance to cope well with dry conditions. In addition, the Bulgarian provenance showed up as most productive in terms of height and radial

  17. Testing and evaluation of a slot and tab construction technique for light-weight wood-fiber-based structural panels under bending

    Science.gov (United States)

    Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

    2015-01-01

    This paper presented construction and strain distributions for light-weight wood-fiber-based structural panels with tri-grid core made from phenolic impregnated laminated paper composites under bending. A new fastening configuration of slots in the faces and tabs on the core was applied to the face/core interfaces of the sandwich panel in addition to epoxy resin. Both...

  18. Synthesis, characterization, and wear and friction properties of variably structured SiC/Si elements made from wood by molten Si impregnation

    DEFF Research Database (Denmark)

    Dhiman, Rajnish; Rana, Kuldeep; Bengu, Erman

    2012-01-01

    We have synthesized pre-shaped SiC/Si ceramic material elements from charcoal (obtained from wood) by impregnation with molten silicon, which takes place in a two-stage process. In the first process, a porous structure of connected micro-crystals of β-SiC is formed, while, in the second process...

  19. 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)

  20. Structure of forest ecosystems and leaf area index of wood plants -results of monitoring over the years 1991-1994

    International Nuclear Information System (INIS)

    Oszlanyi, J.

    1995-01-01

    Monitored characteristics and their dynamics over the last four vegetation seasons reveal the following conclusions: 1) Changes of monitored parameters (e.g. the structure of tree and shrub layer, the leaf area index) are slow, drab and insignificant at the permanent monitoring representing a major part of forest ecosystems of the area affected by the Hydroelectric power structures Gabcikovo. Despite the absence of floods, the ground water level is at a sufficient height to contact rhisosphere of wood plants and the recorded changes are in accord with growth regularities. 2) An increase of the ground water level in the upper part of the monitored territory and a partial renaturation of hydropedological conditions led to an improvement of production-ecological parameters of the area. Changes of its structure are of positive tendency, the leaf area index is stabilised at high values and somewhere even increased (in 1994 being by 70-80% higher than in 1991). 3) Localities with a permanent decrease of the ground water level (band along the old river-bed of the Danube, a dry triangle among the old river-bed of the Danube, the inlet canal and the river arm supplied by the intake structure at Dobrohost and other places) were afflicted by negative changes, locally indicating destruction of tree and shrub layers, with the leaf area index significantly reduced by 20-30%. (author). 1 tab., 5 refs [sk

  1. Low Frequency Vibration approach to asess the Performance of wood structural Systems

    Science.gov (United States)

    Xiping Wang; Robert J. Ross; Michael O. Hunt

    2004-01-01

    The primary means of inspecting buildings and other structures is to evaluate each structure member individually. This is a time consuming process that is expensive, particularly if sheathing or other covering materials must be removed to access the structural members. This paper presents an effort to use a low frequency vibration method for assessing the structural...

  2. Predicting the density of structural timber members in service. The combine use of wood cores and drill resistance data

    Directory of Open Access Journals (Sweden)

    Morales-Condea, M. J.

    2014-09-01

    Full Text Available Drilling devices is used to get information about the cross-section properties and internal defects of structural members. Drill resistance is correlated with density which is often used to predict the mechanical properties of timber elements. However in situ a regression curve cannot be obtained and pre-existent curves provides unreliable predictions. The present paper proposes a procedure for in situ “calibration” of drill resistance data. The “calibration” is based on density values from wood cores taken in the close vicinity of drill holes. Two approaches were tested. One approach based on a regression curve built using wood cores density and drill resistance values obtained from a limited number of members. The other approach uses the information of one wood core to “calibrate” the drill resistance profile taken at the same member. Following this procedure a density prediction is obtained showing a low mean percentage error and a medium coefficient of determination.Los dispositivos de perforación se utilizan a menudo para obtener información sobre las propiedades de la sección transversal y defectos internos de los elementos estructurales de madera. La resistencia a la perforación se correlaciona con la densidad que, a menudo, se utiliza para obtener la predicción de las propiedades mecánicas de los elementos de madera. Sin embargo, una curva de regresión no puede ser obtenida in situ y las curvas de preexistentes proporcionan predicciones poco fiables. En el presente trabajo se propone un procedimiento de “calibración” in situ de los datos de resistencia de perforación obtenidos en cada caso. La “calibración” se basa en los valores de densidad de pequeñas probetas de madera tomadas en las inmediaciones de los taladros. Para ello se plantean 2 métodos: Un primer enfoque basado en obtener una curva de regresión a partir de los valores de densidad de pequeñas probetas de madera y los valores de resistencia a

  3. The meaning of activities in the dwelling and residential environment : A structural approach in people-environment relations.

    NARCIS (Netherlands)

    Meesters, J.

    2009-01-01

    The dwelling is a central setting in people’s everyday life. People use their dwelling and residential environment for a large variety of activities and purposes. This study systematically relates activities, settings and meanings to improve the insight into people-environment relations. This is

  4. Health effects assessment of exposure to particles from wood smoke

    DEFF Research Database (Denmark)

    Nielsen, Elsa

    2007-01-01

    distribution of wood smoke particles, essentially all will be contained in the PM2.5 fraction. In Denmark, recent results indicate that about 10,000 tonnes PM2.5 per year, about half of the total particle emission in Denmark, come from residential wood combustion. Based on a few measurement campaigns conducted...... in Denmark in selected residential areas with different kinds of heating, the annual average PM2.5 exposure from wood smoke can be estimated at 0.4–2 mg/m3 as a preliminary estimate for the whole Danish population. Epidemiological studies evaluating adverse health effects from ambient air pollution...

  5. Evaluation of physical structural features on influencing enzymatic hydrolysis efficiency of micronized wood

    Science.gov (United States)

    Jinxue Jiang; Jinwu Wang; Xiao Zhang; Michael Wolcott

    2016-01-01

    Enzymatic hydrolysis of lignocellulosic biomass is highly dependent on the changes in structural features after pretreatment. Mechanical milling pretreatment is an effective approach to alter the physical structure of biomass and thus improve enzymatic hydrolysis. This study examined the influence of structural characteristics on the enzymatic hydrolysis of micronized...

  6. Residential greenhouse

    Energy Technology Data Exchange (ETDEWEB)

    1985-02-01

    The following report examines the technical and economic viability of residential greenhouse additions in Whitehorse, Yukon. The greenhouse was constructed using the south facing wall of an existing residence as a common wall. Total construction costs were $18,000, including labour. Annual fuel demand for the residence has been reduced by about 10 per cent for an annual saving of $425. In addition, produce to the value of $1,000 is grown annually in the greenhouse for domestic consumption and commercial resale. Typically the greenhouse operates for nine months each year. There is a net thermal loss during the months of November, December and January as a result of the large area of glazing. As well as supplementing the heating supply solar greenhouses can provide additional cash crops which can be used to offset the cost of construction. Humidity problems are minimal and can be dealt with by exhausting high humidity air. One system which has been considered for the greenhouse is to use a standard residential heat pump to remove excess moisture and to pump heat into the house. This would have a secondary benefit of excluding the need to circulate greenhouse air through the house. Thus any allergenic reactions to the greenhouse air would be prevented. 8 refs., 3 figs, 2 tabs.

  7. Multicriteria Decision Analysis of Material Selection of High Energy Performance Residential Building

    Science.gov (United States)

    Čuláková, Monika; Vilčeková, Silvia; Katunská, Jana; Krídlová Burdová, Eva

    2013-11-01

    In world with limited amount of energy sources and with serious environmental pollution, interest in comparing the environmental embodied impacts of buildings using different structure systems and alternative building materials will be increased. This paper shows the significance of life cycle energy and carbon perspective and the material selection in reducing energy consumption and emissions production in the built environment. The study evaluates embodied environmental impacts of nearly zero energy residential structures. The environmental assessment uses framework of LCA within boundary: cradle to gate. Designed alternative scenarios of material compositions are also assessed in terms of energy effectiveness through selected thermal-physical parameters. This study uses multi-criteria decision analysis for making clearer selection between alternative scenarios. The results of MCDA show that alternative E from materials on nature plant base (wood, straw bales, massive wood panel) present possible way to sustainable perspective of nearly zero energy houses in Slovak republic

  8. 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.

  9. The end of the line: The relationship between New York City's subway system and residential class structure

    Science.gov (United States)

    Rhindress, Mindy

    Public money is necessary to build and maintain this country's vast network of mass transit systems and highways. Thus you would expect class equity in choices of infrastructure location, types of projects and pricing. However, the influence of commercial interests appears to create a contradictory effect, and may negatively influence the settlement patterns where transit serves. New York City and its subway system offered the perfect case study by which to examine the before and after effects of mass transit introduction given the enormous size of the transit system and the grand development of New York City that appeared to occur simultaneous to subway inauguration. The main objective of this study was to determine the relationship between the growth of the New York City subway system and the establishment of class structure in residential patterns. Regional census data covering the first 16-year period of the subway's development was examined along with geographic statistics on subway line expansion and station openings. GIS (Geographic Information Systems) maps were used to illustrate the development of living spaces as a function of subway introduction into communities, and several Indices were computed to demonstrate the population growth and class disparity. The results revealed that the early years of transit development were entrepreneurial efforts coordinated by business interests. This led to transit first providing significant benefits mostly to the middle and upper classes, giving them a reasonable means by which to escape horrible tenement living conditions while turning a profit at the same time. Thus new settlements were stratified by class almost immediately after introduction. The cycle continued until years later when the automobile was introduced and the once expensive and luxurious, but now more reasonably priced and just functional, public transit system finally befit the population much lower on the socioeconomic scale. Class divisions still

  10. 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...

  11. Decay extent evaluation of wood degraded by a fungal community using NIRS: application for ecological engineering structures used for natural hazard mitigation

    Science.gov (United States)

    Baptiste Barré, Jean; Bourrier, Franck; Bertrand, David; Rey, Freddy

    2015-04-01

    Ecological engineering corresponds to the design of efficient solutions for protection against natural hazards such as shallow landslides and soil erosion. In particular, bioengineering structures can be composed of a living part, made of plants, cuttings or seeds, and an inert part, a timber logs structure. As wood is not treated by preservatives, fungal degradation can occur from the start of the construction. It results in wood strength loss, which practitioners try to evaluate with non-destructive tools (NDT). Classical NDT are mainly based on density measurements. However, the fungal activity reduces the mechanical properties (modulus of elasticity - MOE) well before well before a density change could be measured. In this context, it would be useful to provide a tool for assessing the residual mechanical strength at different decay stages due to a fungal community. Near-infrared spectroscopy (NIRS) can be used for that purpose, as it can allow evaluating wood mechanical properties as well as wood chemical changes due to brown and white rots. We monitored 160 silver fir samples (30x30x6000mm) from green state to different levels of decay. The degradation process took place in a greenhouse and samples were inoculated with silver fir decayed debris in order to accelerate the process. For each sample, we calculated the normalized bending modulus of elasticity loss (Dw moe) and defined it as decay extent. Near infrared spectra collected from both green and decayed ground samples were corrected by the subtraction of baseline offset. Spectra of green samples were averaged into one mean spectrum and decayed spectra were subtracted from the mean spectrum to calculate the absorption loss. Partial least square regression (PLSR) has been performed between the normalized MOE loss Dw moe (0 wood decay extent in the context of ecological engineering structures used for natural hazard mitigation.

  12. 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...

  13. Exploring the market for third-party-owned residential photovoltaic systems: insights from lease and power-purchase agreement contract structures and costs in California

    International Nuclear Information System (INIS)

    Davidson, Carolyn; Steinberg, Daniel; Margolis, Robert

    2015-01-01

    Over the past several years, third-party-ownership (TPO) structures for residential photovoltaic (PV) systems have become the predominant ownership model in the US residential market. Under a TPO contract, the PV system host typically makes payments to the third-party owner of the system. Anecdotal evidence suggests that the total TPO contract payments made by the customer can differ significantly from payments in which the system host directly purchases the system. Furthermore, payments can vary depending on TPO contract structure. To date, a paucity of data on TPO contracts has precluded studies evaluating trends in TPO contract cost. This study relies on a sample of 1113 contracts for residential PV systems installed in 2010–2012 under the California Solar Initiative to evaluate how the timing of payments under a TPO contract impacts the ultimate cost of the system to the customer. Furthermore, we evaluate how the total cost of TPO systems to customers has changed through time, and the degree to which contract costs have tracked trends in the installed costs of a PV system. We find that the structure of the contract and the timing of the payments have financial implications for the customer: (1) power-purchase contracts, on average, cost more than leases, (2) no-money-down contracts are more costly than prepaid contracts, assuming a customer’s discount rate is lower than 17% and (3) contracts that include escalator clauses cost more, for both power-purchase agreements and leases, at most plausible discount rates. In addition, all contract costs exhibit a wide range, and do not parallel trends in installed costs over time. (letter)

  14. The “housing bubble” and financial factors: Insights from a structural model of the French and Spanish residential markets.

    OpenAIRE

    Antipa, P.; Lecat, R.

    2009-01-01

    Over the last decade, France and Spain have experienced property price and residential investment increases which were among the strongest and the lengthiest in the euro area. Although the quality of the underlying data limits the precision of the estimates, the present paper aims at analysing the fundamental factors behind these evolutions. The analysis presented here assesses whether the observed price dynamics may be attributed to a pure expectation bubble phenomenon or to the large change...

  15. 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.

  16. Bridging gaps: On the performance of airborne LiDAR to model wood mouse-habitat structure relationships in pine forests.

    Science.gov (United States)

    Jaime-González, Carlos; Acebes, Pablo; Mateos, Ana; Mezquida, Eduardo T

    2017-01-01

    LiDAR technology has firmly contributed to strengthen the knowledge of habitat structure-wildlife relationships, though there is an evident bias towards flying vertebrates. To bridge this gap, we investigated and compared the performance of LiDAR and field data to model habitat preferences of wood mouse (Apodemus sylvaticus) in a Mediterranean high mountain pine forest (Pinus sylvestris). We recorded nine field and 13 LiDAR variables that were summarized by means of Principal Component Analyses (PCA). We then analyzed wood mouse's habitat preferences using three different models based on: (i) field PCs predictors, (ii) LiDAR PCs predictors; and (iii) both set of predictors in a combined model, including a variance partitioning analysis. Elevation was also included as a predictor in the three models. Our results indicate that LiDAR derived variables were better predictors than field-based variables. The model combining both data sets slightly improved the predictive power of the model. Field derived variables indicated that wood mouse was positively influenced by the gradient of increasing shrub cover and negatively affected by elevation. Regarding LiDAR data, two LiDAR PCs, i.e. gradients in canopy openness and complexity in forest vertical structure positively influenced wood mouse, although elevation interacted negatively with the complexity in vertical structure, indicating wood mouse's preferences for plots with lower elevations but with complex forest vertical structure. The combined model was similar to the LiDAR-based model and included the gradient of shrub cover measured in the field. Variance partitioning showed that LiDAR-based variables, together with elevation, were the most important predictors and that part of the variation explained by shrub cover was shared. LiDAR derived variables were good surrogates of environmental characteristics explaining habitat preferences by the wood mouse. Our LiDAR metrics represented structural features of the forest

  17. 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...

  18. P.E.I. wood fuel survey, 1990-91

    International Nuclear Information System (INIS)

    1991-04-01

    In 1991 a wood fuel survey of 450 randomly selected households, representing 1% of the total number of households in Prince Edward Island, was conducted. The survey indicated that 49.8% of the households burned wood, up from 42.1% of households in the 1988-1989 survey. The wood burning households consumed an average of 4.92 cords of wood, consistent with the 4.90 cords in the 1989 survey. The total residential wood consumption was estimated at ca 100,377 cords, an increase from the 89,000 cords used in 1988-89. Wood cutters represented 23.4% of respondents, with buyers representing 25.4% of respondents. The wood burning appliances used by the respondents were: airtight wood stove 39.9%, wood furnace 22.5%, kitchen wood stove 15.7%, combined wood/oil furnace 8.9%, Franklin/non-airtight 4.4%, Kemac unit 4.4%, fireplace insert 3.1%, and open fireplace 1%. The most frequent response among rural wood users cited price as an advantage of wood fuel, while the most frequent response of urban users cited the quality of the heat. 9 figs., 47 tabs

  19. Determining stocks and flows of structural wood products in single family homes in the United States between 1950 and 2010

    DEFF Research Database (Denmark)

    Sianchuk, Robert A.; McFarlane, Paul N.; Ackom, Emmanuel

    2012-01-01

    The stocks and flows of six major structural wood products (SWPs)-lumber, plywood, oriented strand board [OSB], glue laminated timber, I-joists, and laminated veneer lumber (LVL)-in US single family homes were modeled from 1950 to 2010. The consumption of these products in US single family homes...... and their emissions as construction and demolition wastes were estimated. The net consumption of SWPs decreased from 119 kg/m2 constructed in 1986 to 82 kg/m2 in 2010. Softwood lumber was consistently the predominant SWP, but its usage intensity decreased from 95 kg/m2 in 1986 to 52 kg/ m2 in 2010. Since the 1980s......, modern SWPs, such as I-joists, LVL, and OSB, have replaced lumber and plywood products. The needs of the US single family housing industry have been met by a smaller mass of SWPs per unit area constructed. The mass of SWP present in construction wastes was influenced strongly by building cycles...

  20. In individual or collective dwellings, wood-fuel: an enthusiastic market

    International Nuclear Information System (INIS)

    Anon.

    2007-01-01

    The wood-fuel market benefits from the present day development of renewable energy sources, both in the individual residential sector where wood-fuel is becoming a main space-heating solution and not only an auxiliary one, and in the collective residential, tertiary and industrial sectors where more than 1850 wood-burning facilities have been implemented in 6 years under the impulse of the wood-fuel development plan. Sales have raised by 40% in the residential sector in 2006 and a 50% increase of renewable energy sources is expected in the heat generation sector from now to 2010. This article presents the main trends of the French wood-fuel market and the existing offer of wood-fuel boilers. (J.S.)

  1. Fungal community structure of fallen pine and oak wood at different stages of decomposition in the Qinling Mountains, China.

    Science.gov (United States)

    Yuan, Jie; Zheng, Xiaofeng; Cheng, Fei; Zhu, Xian; Hou, Lin; Li, Jingxia; Zhang, Shuoxin

    2017-10-24

    Historically, intense forest hazards have resulted in an increase in the quantity of fallen wood in the Qinling Mountains. Fallen wood has a decisive influence on the nutrient cycling, carbon budget and ecosystem biodiversity of forests, and fungi are essential for the decomposition of fallen wood. Moreover, decaying dead wood alters fungal communities. The development of high-throughput sequencing methods has facilitated the ongoing investigation of relevant molecular forest ecosystems with a focus on fungal communities. In this study, fallen wood and its associated fungal communities were compared at different stages of decomposition to evaluate relative species abundance and species diversity. The physical and chemical factors that alter fungal communities were also compared by performing correspondence analysis according to host tree species across all stages of decomposition. Tree species were the major source of differences in fungal community diversity at all decomposition stages, and fungal communities achieved the highest levels of diversity at the intermediate and late decomposition stages. Interactions between various physical and chemical factors and fungal communities shared the same regulatory mechanisms, and there was no tree species-specific influence. Improving our knowledge of wood-inhabiting fungal communities is crucial for forest ecosystem conservation.

  2. Guidelines for residential commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Wray, Craig P.; Walker, Iain S.; Sherman, Max H.

    2003-01-31

    Currently, houses do not perform optimally or even as many codes and forecasts predict, largely because they are field assembled and there is no consistent process to identify problems or to correct them. Residential commissioning is a solution to this problem. This guide is the culmination of a 30-month project that began in September 1999. The ultimate objective of the project is to increase the number of houses that undergo commissioning, which will improve the quality, comfort, and safety of homes for California citizens. The project goal is to lay the groundwork for a residential commissioning industry in California focused on end-use energy and non-energy issues. As such, we intend this guide to be a beginning and not an end. Our intent is that the guide will lead to the programmatic integration of commissioning with other building industry processes, which in turn will provide more value to a single site visit for people such as home energy auditors and raters, home inspectors, and building performance contractors. Project work to support the development of this guide includes: a literature review and annotated bibliography, which facilitates access to 469 documents related to residential commissioning published over the past 20 years (Wray et al. 2000), an analysis of the potential benefits one can realistically expect from commissioning new and existing California houses (Matson et al. 2002), and an assessment of 107 diagnostic tools for evaluating residential commissioning metrics (Wray et al. 2002). In this guide, we describe the issues that non-experts should consider in developing a commissioning program to achieve the benefits we have identified. We do this by providing specific recommendations about: how to structure the commissioning process, which diagnostics to use, and how to use them to commission new and existing houses. Using examples, we also demonstrate the potential benefits of applying the recommended whole-house commissioning approach to

  3. Probing chemistry within the membrane structure of wood with soft X-ray spectral microscopy

    International Nuclear Information System (INIS)

    Cody, George D.

    2000-01-01

    Scanning Transmission Soft X-ray spectral microscopy on Carbon's 1s absorption edge reveals the distribution of structural biopolymers within cell membrane regions of modern cedar and oak. Cellulose is extremely susceptible to beam damage. Spectroscopic studies of beam damage reveals that the chemical changes resulting from secondary electron impact may be highly selective and is consistent with hydroxyl eliminations and structural rearrangement of pyranose rings in alpha-cellulose to hydroxyl substituted γ pyrones. A study of acetylated cellulose demonstrates significantly different chemistry; principally massive decarboxylation. Defocusing the beam to a 2 μm spot size allows for the acquisition of 'pristine' cellulose spectra. Spectral deconvolution is used to assess the distribution of lignin and cellulose in the different regions of the cell membrane. Using the intensity of the hydroxylated aromatic carbons 1s-π * transition, the ratio of coniferyl and syringyl based lignin within the middle lamellae and secondary cell wall of oak, an angiosperm can be determined

  4. The performance of energy efficient residential building envelope systems

    Energy Technology Data Exchange (ETDEWEB)

    Proskiw, G.

    1996-08-01

    The adequacy and durability of residential building envelope systems under actual field conditions were evaluated. A building envelope offers protection from cold, heat, moisture, wind and noise. However, they are exposed to thermal, structural, and moisture stresses and their performance can degrade over time. Envelope performance was evaluated at 20 energy efficient and four conventional, detached modern homes in Winnipeg, Canada. The three complementary measurement tools were wood moisture content (WMC) of framing members, thermographic examinations, and airtightness tests. As expected, energy efficient building envelope systems performed better than the conventional systems. No evidence of envelope degradation was found in any of the energy efficient houses. The building envelopes using polyethylene air barriers performed slightly better than those which used the airtight drywall approach, although both were considered satisfactory. WMC levels were a bit lower in the polyethylene-clad house. 1 ref., 1 tab.

  5. Okanagan indoor wood burning appliance inventory survey

    International Nuclear Information System (INIS)

    2001-01-01

    A survey was conducted to determine the usage and nature of wood burning appliances used by residents in British Columbia's Okanagan region. The objective was to better understand this source of air quality concern and to facilitate strategic planning, guidelines and legislation. The survey also provides a baseline to track the effectiveness of any reduction strategies. It identifies the different types of wood burning appliances used in the community and presents residential options about potential bylaws to protect air quality. The receptivity of households to switch to more efficient wood burning appliances was also examined. The survey completes a portion of an overall emissions inventory for the Okanagan Valley. Environment Canada uses the particulate loading results to model the air quality in the airshed. Results showed that approximately 21 per cent of the households in the Okanagan use indoor wood burning appliances, and burn an average of 2.3 cords of wood each year. Only 11 per cent of the appliances are considered to have advanced burning technology. It is projected that the use of wood burning appliances in the Okanagan will increase by 5 to 7 per cent in the next 2 years. Most residents have good burning habits, but some improvements can still be made. Many residents are considering exchanging old wood burning appliances for clean burning technology appliances for environmental and health reasons. Most households would support a bylaw to control nuisance amounts of smoke from wood burning appliances. 20 tabs., 5 figs

  6. Framing Failures in Wood-Frame Hip Roofs under Extreme Wind Loads

    Directory of Open Access Journals (Sweden)

    Sarah A. Stevenson

    2018-02-01

    Full Text Available Wood-frame residential roof failures are among the most common and expensive types of wind damage. Hip roofs are commonly understood to be more resilient during extreme wind in relation to gable roofs. However, inspection of damage survey data from recent tornadoes has revealed a previously unstudied failure mode in which hip roofs suffer partial failure of the framing structure. In the current study, evidence of partial framing failures and statistics of their occurrence are explored and discussed, while the common roof design and construction practice are reviewed. Two-dimensional finite element models are developed to estimate the element-level load effects on hip roof trusses and stick-frame components. The likelihood of failure in each member is defined based on relative demand-to-capacity ratios. Trussed and stick-frame structures are compared to assess the relative performance of the two types of construction. The present analyses verify the common understanding that toenailed roof-to-wall connections are likely to be the most vulnerable elements in the structure of a wood-frame hip roof. However, the results also indicate that certain framing members and connections display significant vulnerability under the same wind uplift, and the possibility of framing failure is not to be discounted. Furthermore, in the case where the roof-to-wall connection uses hurricane straps, certain framing members and joints become the likely points of failure initiation. The analysis results and damage survey observations are used to expand the understanding of wood-frame residential roof failures, as they relate to the Enhanced Fujita Scale and provide assessment of potential gaps in residential design codes.

  7. The incorporation of wood waste ash as a partial cement replacement material for making structural grade concrete: An overview

    Directory of Open Access Journals (Sweden)

    Swaptik Chowdhury

    2015-06-01

    Full Text Available With increasing industrialization, the industrial byproducts (wastes are being accumulated to a large extent, leading to environmental and economic concerns related to their disposal (land filling. Wood ash is the residue produced from the incineration of wood and its products (chips, saw dust, bark for power generation or other uses. Cement is an energy extensive industrial commodity and leads to the emission of a vast amount of greenhouse gases, forcing researchers to look for an alternative, such as a sustainable building practice. This paper presents an overview of the work and studies done on the incorporation of wood ash as partial replacement of cement in concrete from the year 1991 to 2012. The aspects of wood ash such as its physical, chemical, mineralogical and elemental characteristics as well as the influence of wood ash on properties such as workability, water absorption, compressive strength, flexural rigidity test, split tensile test, bulk density, chloride permeability, freeze thaw and acid resistance of concrete have been discussed in detail.

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

    Science.gov (United States)

    David B. McKeever; Joe Elling

    2014-01-01

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

  9. Emissions from residential combustion of different solid fuels. Roekgasemissioner vid anvaendning av olika fasta braenslen i smaaskaliga system

    Energy Technology Data Exchange (ETDEWEB)

    Rudling, L

    1983-01-01

    The emission from different types of solid fuels during combustion in residential furnaces and stoves has been investigated. The following fules were investigated: wood pellets, peat-bark pellets, wood chips, wood logs,wood-briquets, peat briquets, lignite briquets, fuel oil. Three different 20-25 kW boilers were used and one stove and one fire place. The flue gases were analysed for carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, particulates, tar and fluoranthen.

  10. On methods of sustainable architectural design of bio-positive buildings in the low-rise residential development structure

    Directory of Open Access Journals (Sweden)

    Zhogoleva Anna

    2017-01-01

    Full Text Available The purpose of the author’s research is to determine the actual content of sustainable architectural design for suburban residential development. In accordance with the methodology of area sustainable development the traditional architectural design according to the rules and regulations is completed with additional approaches and methods. As a result, methods of bio-positive design of buildings have been studied and defined, including: the principle of planning transformations, the use of environmentally friendly, local building materials and design concepts, energy-efficient architectural design, the use of alternative energy in building operation, the design of the energy intake and accumulationsystems, the architectural and landscape design that ensures stable functioning of autonomous, sustainable biosystems on the site, non-waste functioning of architectural objects, introduction of waste disposal systems in the project.

  11. Competitive outcomes between wood-decaying fungi are altered in burnt wood.

    Science.gov (United States)

    Edman, Mattias; Eriksson, Anna-Maria

    2016-06-01

    Fire is an important disturbance agent in boreal forests where it creates a wide variety of charred and other types of heat-modified dead wood substrates, yet how these substrates affect fungal community structure and development within wood is poorly understood. We allowed six species of wood-decaying basidiomycetes to compete in pairs in wood-discs that were experimentally burnt before fungal inoculation. The outcomes of interactions in burnt wood differed from those in unburnt control wood for two species:Antrodia sinuosanever lost on burnt wood and won over its competitor in 67% of the trials compared to 40% losses and 20% wins on unburnt wood. In contrast, Ischnoderma benzoinumwon all interactions on unburnt wood compared to 33% on burnt wood. However, the responses differed depending on the identity of the competing species, suggesting an interaction between competitor and substrate type. The observed shift in competitive balance between fungal species probably results from chemical changes in burnt wood, but the underlying mechanism needs further investigation. Nevertheless, the results indicate that forest fires indirectly structure fungal communities by modifying dead wood, and highlight the importance of fire-affected dead wood substrates in boreal forests. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Fatigue testing of wood-concrete composite beams.

    Science.gov (United States)

    2013-05-01

    Currently, wood-concrete composite structural members are usually applied in building structures. There are a relatively small number (in the low 100s) of known bridge applications involving wood-concrete composites. A problem with using these novel ...

  13. Analysis of existing structure and emissions of wood combustion plants for the production of heat and electricity in Bavaria; Analyse der Bestandesstruktur und der Emissionen von Holzfeuerungsanlagen zur Erzeugung von Waerme und Strom in Bayern.

    Energy Technology Data Exchange (ETDEWEB)

    Joa, Bettina

    2014-07-01

    This work deals with the detailed analysis of the existing structure of all Bavarian wood burning plants for the generation of heat and electricity as well as the determination of the resulting emission emissions in 2013. The number of wood burning plants in the single-chamber fireplaces, wood central heating and wood-fired heating plants which are in operation in the year 2013 were determined, and how many plants are existing in the various areas like pellet stoves, traditional ovens, wood-burning fireplace, pellet central heating systems, wood chips central heating systems, fire-wood central heating systems, wood combined heat and power plant (electricity and heat) and wood power plants (heat). In addition, the regional distribution of the wood burning plants in the Bavarian governmental districts is investigated as well as the type and amount of energy produced by them (heat, electricity). [German] Diese Arbeit behandelt die detaillierte Analyse der Bestandesstruktur saemtlicher bayerischer Holzfeuerungsanlagen zur Erzeugung von Waerme und Strom sowie die Ermittlung des dabei entstehenden Emissionsausstosses im Jahr 2013. Dabei wurde ermittelt wie viele Holzfeuerungsanlagen in den Segmenten Einzelraumfeuerstaetten, Holz-Zentralheizungen und Holzheiz(kraft)werke im Jahr 2013 in Bayern in Betrieb sind und wie viele Anlagen es in den einzelnen Bereichen Pelletoefen, traditionelle Oefen, Kaminoefen, Heizkamine, offene Kamine, Kacheloefen, Pellet-Zentralheizungen, Hackschnitzel-Zentralheizungen, Scheitholz-Zentralheizungen, Holzheizkraftwerke (Waerme und Strom), Holzheizwerke (Waerme) sowie Holzkraftwerke (Strom) gibt. Des Weiteren wird die regionale Verteilung der Holzfeuerungsanlagen in den bayerischen Regierungsbezirken erforscht sowie die durch sie produzierte Art und Menge an Energie (Waerme, Strom).

  14. A chemometric investigation of aromatic emission profiles from a marine engine in comparison with residential wood combustion and road traffic: Implications for source apportionment inside and outside sulphur emission control areas

    Science.gov (United States)

    Czech, Hendryk; Stengel, Benjamin; Adam, Thomas; Sklorz, Martin; Streibel, Thorsten; Zimmermann, Ralf

    2017-10-01

    Ship emissions are known to cause severe impacts on human health, but are less restricted than land-based emissions. A regulation to improve air quality in coastal regions and frequented waterways is the limitation of fuel sulphur content to 0.1% in sulphur emission control areas (SECAs), which has caused a switch from heavy fuel oil (HFO) towards diesel-like marine gas oil (MGO) or marine diesel oil (MDO). The fraction of aromatic organic vapours in the exhaust from a marine engine, operating on HFO and MGO, was investigated by resonance-enhanced multi-photon ionisation time-of-flight mass spectrometry (REMPI-TOFMS). MGO with fuel sulphur content (FSC) below 0.1% and HFO with an average FSC of 2.7% denote representative marine fuels inside and outside SECAs, respectively. The obtained emission spectra were combined with data of previous REMPI-TOFMS studies of combustion engines and wood combustion in statistical analyses to derive marker substances for ship emissions inside and outside SECAs. A diagnostic ratio of C2-naphthalenes to methyl-naphthalenes was found to hold for a good discriminator between ship emissions on the one hand and road traffic and wood combustion on the other hand. Furthermore, random REMPI spectra from all emission sources were mixed with different proportions in a simulation to create a model based on partial least square (PLS) regression for the prediction of ship contribution to aromatic organic vapours. We point out that in particular PAHs with higher degree of alkylation are significant markers for primary ship emissions which may support source apportionment studies inside and outside SECAs to assess the benefits of fuel sulphur content regulation on air quality.

  15. Reduce tax on residential mobility

    NARCIS (Netherlands)

    van Ewijk, C.; van Leuvensteijn, M.

    2010-01-01

    How can Europe increase structural growth? This column argues that labour market flexibility is key. As a major barrier to labour movement is rigidity in the housing market, abolishing transfer taxes on residential property could result in gains of up to 0.4% of GDP.

  16. Application of molecular genetic methods for identification of wood-decaying fungi in wood constructions

    OpenAIRE

    Elena Bobeková; Michal Tomšovský; Petr Horáček

    2008-01-01

    The aim of the paper is to evaluate the utilization of molecular biology methods for detection of wood decaying fungi directly from decomposed wood using a commercial DNA extraction kit developed for soil substrates (PowerSoil™ DNA isolation kit). The experiment based on dry rot fungus (Serpula lacrymans) detection from inoculated wooden pieces under laboratory conditions was followed by field detection of wood-decaying fungi from wood structures on building constructions. Fungal DNA was ide...

  17. 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.

  18. Integrated Strip Foundation Systems for Small Residential Buildings

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2010-01-01

    A prefabricated lightweight element was designed for a strip foundation that was used on site as the bases of two small residential buildings, in this case single-family houses; one was built with a double-brick exterior wall separated by mineral fiber insulation and the other was built with a wood...

  19. 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

  20. Adaptation of methodology to select structural alternatives of one-way slab in residential building to the guidelines of the European Committee for Standardization (CEN/TC 350)

    Energy Technology Data Exchange (ETDEWEB)

    Fraile-Garcia, Esteban, E-mail: esteban.fraile@unirioja.es [University of La Rioja, Department of Mechanical Engineering (Spain); Ferreiro-Cabello, Javier, E-mail: javier.ferreiro@unirioja.es [University of La Rioja, Department of Mechanical Engineering (Spain); Qualiberica S.L. (Spain); Martinez-Camara, Eduardo, E-mail: eduardo.martinezc@unirioja.es [University of La Rioja, Department of Mechanical Engineering (Spain); Jimenez-Macias, Emilio, E-mail: emilio.jimenez@unirioja.es [University of La Rioja, Department of Electrical Engineering (Spain)

    2015-11-15

    The European Committee for Standardization (CEN) through its Technical Committee CEN/TC-350 is developing a series of standards for assessing the building sustainability, at both product and building levels. The practical application of the selection (decision making) of structural alternatives made by one-way slabs leads to an intermediate level between the product and the building. Thus the present study addresses this problem of decision making, following the CEN guidelines and incorporating relevant aspects of architectural design into residential construction. A life cycle assessment (LCA) is developed in order to obtain valid information for the decision making process (the LCA was developed applying CML methodology although Ecoindicator99 was used in order to facilitate the comparison of the values); this information (the carbon footprint values) is contrasted with other databases and with the information from the Environmental Product Declaration (EPD) of one of the lightening materials (expanded polystyrene), in order to validate the results. Solutions of different column disposition and geometries are evaluated in the three pillars of sustainable construction on residential construction: social, economic and environmental. The quantitative analysis of the variables used in this study enables and facilitates an objective comparison in the design stage by a responsible technician; the application of the proposed methodology reduces the possible solutions to be evaluated by the expert to 12.22% of the options in the case of low values of the column index and to 26.67% for the highest values. - Highlights: • Methodology for selection of structural alternatives in buildings with one-way slabs • Adapted to CEN guidelines (CEN/TC-350) for assessing the building sustainability • LCA is developed in order to obtain valid information for the decision making process. • Results validated comparing carbon footprint, databases and Env. Product Declarations

  1. Common wood decay fungi found in the Caribbean Basin

    Science.gov (United States)

    D. Jean. Lodge

    2016-01-01

    There are hundreds of wood-decay fungi in the Caribbean Basin, but relatively few of these are likely to grow on manmade structures built of wood or wood-composites. The wood-decay fungi of greatest concern are those that cause brown-rot, and especially brown-rot fungi that are resistant to copper-based wood preservatives. Some fungi that grow in the Caribbean and...

  2. An assessment of management practices of wood and wood-related wastes in the urban environment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The US Environmental Protection Agency estimates that yard waste{sup 1} accounts for approximately 16% of the municipal solid waste (MSW) stream (US EPA, 1994). Until recently, specific data and related information on this component of the (MSW) stream has been limited. The purposes of this study, phase two of the three-phase assessment of urban wood waste issues, are to assess and describe current alternatives to landfills for urban wood waste management; provide guidance on the management of urban wood waste to organizations that produce or manage wood waste; and clarify state regulatory and policy positions affecting these organizations. For this study, urban wood waste is defined as solid waste generated by tree and landscape maintenance services (public and private). Urban wood waste includes the following materials: unchipped mixed wood, unchipped logs, and unchipped tops and brush; clearing and grubbing waste; fall leaves and grass clippings; and chips and whole stumps. Construction and demolition debris and consumer-generated yard waste are not included in this study. Generators of urban wood waste include various organizations; municipal, county, and commercial tree care divisions; nurseries, orchards, and golf courses; municipal park and recreation departments; and electric and telephone utility power line maintenance, excavator and land clearance, and landscape organizations. (1) US EPA defines yard waste as ''yard trimmings'' which includes ''grass, leaves and tree brush trimmings from residential, institutional, and commercial sources.''

  3. Structure of the community of nesting birds in a ravine oak wood in the valley of the Oskol river

    Directory of Open Access Journals (Sweden)

    A. A. Atemasov

    2016-10-01

    nesting in the crown were 32.3% and ground-nesting species 25.3%. The geographical and genesis structure of the communities of nesting birds are characterized by predominance of species from Nemoral and Ancient-Nemoral faunal assemblage (in some years up to 90.9% of the population. The species from the forest-steppe faunistic complex of the European type of fauna account for 3.6% to 9.48% of the population of nesting birds, and most of these have the status of third-degree (rare species. The composition of the group of third-degree species is highly diverse: in addition to the elements of Nemoral, Ancient-Nemoral and forest-steppe complexes, it includes species from the tropical and boreal groups. Among third-degree species there is a tendency to decrease in some species from the Nemoral faunal complex with a simultaneous increase in the forest-steppe faunistic component and increase in the homogeneity of the geography-genesis structure as a whole. The significant share of the population from the Nemoral and Ancient-Nemoral species complex, which formed in deciduous forests, is evidence of the origin of the  researched ravine oak wood as a remnant of the once vast oak-forest areas.

  4. Impact of clay mineral, wood sawdust or root organic matter on the bacterial and fungal community structures in two aged PAH-contaminated soils.

    Science.gov (United States)

    Cébron, Aurélie; Beguiristain, Thierry; Bongoua-Devisme, Jeanne; Denonfoux, Jérémie; Faure, Pierre; Lorgeoux, Catherine; Ouvrard, Stéphanie; Parisot, Nicolas; Peyret, Pierre; Leyval, Corinne

    2015-09-01

    The high organic pollutant concentration of aged polycyclic aromatic hydrocarbon (PAH)-contaminated wasteland soils is highly recalcitrant to biodegradation due to its very low bioavailability. In such soils, the microbial community is well adapted to the pollution, but the microbial activity is limited by nutrient availability. Management strategies could be applied to modify the soil microbial functioning as well as the PAH contamination through various amendment types. The impact of amendment with clay minerals (montmorillonite), wood sawdust and organic matter plant roots on microbial community structure was investigated on two aged PAH-contaminated soils both in laboratory and 1-year on-site pot experiments. Total PAH content (sum of 16 PAHs of the US-EPA list) and polar polycyclic aromatic compounds (pPAC) were monitored as well as the available PAH fraction using the Tenax method. The bacterial and fungal community structures were monitored using fingerprinting thermal gradient gel electrophoresis (TTGE) method. The abundance of bacteria (16S rRNA genes), fungi (18S rRNA genes) and PAH degraders (PAH-ring hydroxylating dioxygenase and catechol dioxygenase genes) was followed through qPCR assays. Although the treatments did not modify the total and available PAH content, the microbial community density, structure and the PAH degradation potential changed when fresh organic matter was provided as sawdust and under rhizosphere influence, while the clay mineral only increased the percentage of catechol-1,2-dioxygenase genes. The abundance of bacteria and fungi and the percentage of fungi relative to bacteria were enhanced in soil samples supplemented with wood sawdust and in the plant rhizospheric soils. Two distinct fungal populations developed in the two soils supplemented with sawdust, i.e. fungi related to Chaetomium and Neurospora genera and Brachyconidiellopsis and Pseudallescheria genera, in H and NM soils respectively. Wood sawdust amendment favoured the

  5. 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.)

  6. Comparing energy use and environmental emissions of reinforced wood doors and steel doors

    Science.gov (United States)

    Lynn Knight; Melissa Huff; Janet I. Stockhausen; Robert J. Ross

    2005-01-01

    The USDA Forest Service Forest Products Laboratory has patented a technology that incorporates fiberglass-reinforced wood into the structure of wood doors and other wood building products. The process of reinforcing wood doors with epoxy and fiberglass increases the strength and durability of the product. Also, it allows the use of low-value, small-diameter wood which...

  7. Indoor air pollution caused by wood-burning in Brazilian and Danish dwellings

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo; Jensen, Ole Michael; da Cruz Tarelho, Luís António

    2013-01-01

    Residential wood-burning is considered by the scientific community as the 4th major cause of deaths in the developing countries due to the indoor air contamination and a cause of regional air pollution in the northern countries. In the first case, wood is being used by low income people that stil...

  8. Evaluation of various fire retardants for use in wood flour--polyethylene composites

    Science.gov (United States)

    Nicole M. Stark; Robert H. White; Scott A. Mueller; Tim A. Osswald

    2010-01-01

    Wood-plastic composites represent a growing class of materials used by the residential construction industry and the furniture industry. For some applications in these industries, the fire performance of the material must be known, and in some cases improved. However, the fire performance of wood-plastic composites is not well understood, and there is little...

  9. 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.

  10. Regulation of air pollution from wood-burning stoves

    DEFF Research Database (Denmark)

    Bjørner, Thomas Bue; Brandt, Jørgen; Hansen, Lars Gårn

    Air pollution is a major global challenge. Emissions from residential wood-burning stoves make a surprisingly large contribution to total air pollution related health costs. In Denmark, emissions from wood-burning stoves are calculated to cause almost 400 premature deaths each year within Denmark...... and additionally about 300 premature deaths in other parts of Europe. In this article, we present an integrated assessment of the net social benefit of different schemes for regulating wood-burning stoves including bans and taxes. The assessment uses high resolution air pollution emission inventory...

  11. Influence of wood defects on some mechanical properties of two ...

    African Journals Online (AJOL)

    Effects of slope of wood grain, knot, split, ingrowth and sapwood on some mechanical wood properties of Pterygota macrocarpa (Kyere) and Piptadeniastrum africanum (Dahoma) have been studied, using structural size specimens and a 60 tonne structural wood testing machine. The study on the two tropical hardwoods ...

  12. Unpalatable plants facilitate tree sapling survival in wooded pastures

    NARCIS (Netherlands)

    Smit, C.; Ouden, den J.; Müller-Schärer, H.

    2006-01-01

    Summary 1. In endangered wooded pasture ecosystems established tree saplings are frequently found in spatial association with protective structures, suggesting nurse effects. This associational resistance is thought to be a driving force behind tree regeneration in wooded pastures. Experimental

  13. STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION MODEL FOR THE WOOD PRESERVATIVE SCENARIO (SHEDS-WOOD), VERSION 2 MODEL SAS CODE

    Science.gov (United States)

    Concerns have been raised regarding the safety of young children contacting arsenic and chromium residues while playing on and around Chromated Copper Arsenate (CCA) treated wood playground structures and decks. Although CCA registrants voluntarily canceled treated wood for resi...

  14. Residential firewood use in the United States.

    Science.gov (United States)

    Lipfert, F W; Dungan, J L

    1983-03-25

    An empirical relation between residential firewood use and population density was developed from survey data for 64 counties in New England and was corroborated by data from other states. The results indicate that usage is concentrated in urbanized areas of the Northeast and north central states and that about 9.0 to 11.0 percent of U.S. space heating input is from firewood. No constraints due to the supply of wood were apparent in 1978-1979. These findings have implications for effects on air quality.

  15. 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

  16. Measure Guideline. Wood Window Repair, Rehabilitation, and Replacement

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States); Eng, P. [Building Science Corporation, Somerville, MA (United States)

    2012-12-01

    This measure guideline provides information and guidance on rehabilitating, retrofitting, and replacing existing window assemblies in residential construction. The intent is to provide information regarding means and methods to improve the energy and comfort performance of existing wood window assemblies in a way that takes into consideration component durability, in-service operation, and long term performance of the strategies.

  17. Structure, electrical resistivity, and thermal conductivity of beech wood biocarbon produced at carbonization temperatures below 1000°C

    Science.gov (United States)

    Parfen'eva, L. S.; Orlova, T. S.; Kartenko, N. F.; Smirnov, B. I.; Smirnov, I. A.; Misiorek, H.; Jezowski, A.; Muha, J.; Vera, M. C.

    2011-11-01

    This paper reports on measurements of the thermal conductivity κ and the electrical resistivity ρ in the temperature range 5-300 K, and, at 300 K, on X-ray diffraction studies of high-porosity (with a channel pore volume fraction of ˜47 vol %) of the beech wood biocarbon prepared by pyrolysis (carbonization) of tree wood in an argon flow at the carbonization temperature T carb = 800°C. It has been shown that the biocarbon template of the samples studied represents essentially a nanocomposite made up of amorphous carbon and nanocrystallites—"graphite fragments" and graphene layers. The sizes of the nanocrystallites forming these nanocomposites have been determined. The dependences ρ( T) and κ( T) have been measured for the samples cut along and perpendicular to the tree growth direction, thus permitting determination of the magnitude of the anisotropy of these parameters. The dependences ρ( T) and κ( T), which have been obtained for beech biocarbon samples prepared at T carb = 800°C, are compared with the data amassed by us earlier for samples fabricated at T carb = 1000 and 2400°C. The magnitude and temperature dependence of the phonon thermal conductivity of the nanocomposite making up the beech biocarbon template at T carb = 800°C have been found.

  18. Characterization of structure and development of models to quantify wood potential of an unmanaged Araucaria angustifolia stand

    Directory of Open Access Journals (Sweden)

    Rafaella De Angeli Curto

    2014-12-01

    Full Text Available The objective of this study was to characterize of an unmanaged stand of Araucaria angustifolia and to development of models to quantify the wood potential, aiming to support the development of forest management plans in stands with similar conditions. The work was developed into a stand established in 1946, in National Forest of Açungui, in Campo Largo County, Paraná State, Brazil. There was only one thinning in the stand, between 1970 and 1980. From the frequency of individuals in each diametric class, it was observed the condition of stagnation and competition with cohort in the beginning of class distribution. With the application of the probability density function of Weibull-3P, Trorey model, and the 5th polynomial by diameter class, it was possible to confirm the stock estimative of timber volume of the stand. This analysis indicated that the stand presents average annual wood production smaller than the species potential. So it is recommended the thinning to promote growth of remnant trees. With the probability density function of Weibull-3p, that was selected, it is possible to project the diametric distribution of the stand, when analyzed complementarily with growth diameter information, if the stand remains unmanaged. Certainly, the optimum potential of timber production could have been manifested if the stand were managed during the cycle planed.

  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. Structural health and dynamic behavior of residential buildings: field challenges in the rehab of damaged reinforced concrete

    Directory of Open Access Journals (Sweden)

    Chalhoub M. S.

    2014-01-01

    Full Text Available Reinforced concrete buildings require special consideration under dynamic excitations due to their anisotropic material properties. Strain compatibility equations are used in concrete analysis and design with assumptions about the stress and strain field across member section and member length. However, these assumptions fall short of describing real life behavior when concrete elements deteriorate, age or undergo cyclic loading. This paper addresses the structural health of reinforced concrete buildings and proposes an analytical model to account for concrete damage through loss of bond. The proposed model relates steel loading that causes bond distress to design parameters such as development length and bar properties, and therefore could be complemented by field measurement. The paper proposes a diagnosis method and discusses the sustainability of the structure by assisting in a simplistic decision rule as to whether to perform minor fixes, major rehabilitation, or disposal. Emphasis is placed on the difference between reversible and irreversible effects of cyclic loading on structural behaviour, and draws a distinction between damage to the girder and damage to the column in the overall structural system. The model is compared to empirical results to address field challenges faced when the structure is subjected to severe conditions in its ambient environment, or to unusual loading. Deterioration in concrete causes alteration in its composite behavior with the reinforcing steel. This affects the fundamental period of the structure, and its response to seismic loading.

  1. Polycyclic Aromatic Hydrocarbons in Fine Particulate Matter Emitted from Burning Kerosene, Liquid Petroleum Gas, and Wood Fuels in Household Cookstoves

    Science.gov (United States)

    This study measured polycyclic aromatic hydrocarbon (PAH) composition in particulate matter emissions from residential cookstoves. A variety of fuel and cookstove combinations were examined, including: (i) liquid petroleum gas (LPG), (ii) kerosene in a wick stove, (iii) wood (10%...

  2. Uma visão sobre a estrutura, composição e biodegradação da madeira A vision of wood structure, composition and biodegradation

    Directory of Open Access Journals (Sweden)

    Walter Carvalho

    2009-01-01

    Full Text Available Wood is the main raw material used in the pulp and paper industry. It is a material that presents heterogeneous structure and complex composition, which results in a relatively resistant material to the biodegradation process. In the present review, we attempted to summarize the structural characteristics of wood and describe the chemical nature of its major components to, afterwards, comment about its biodegradation. The role of the enzyme manganese peroxidase in the lignin degradation by a selective white-rot fungus, Ceriporiopsis subvermispora, was highlighted.

  3. Big mountains but small barriers: population genetic structure of the Chinese wood frog (Rana chensinensis) in the Tsinling and Daba Mountain region of northern China.

    Science.gov (United States)

    Zhan, Aibin; Li, Cheng; Fu, Jinzhong

    2009-04-09

    Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis) to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high elevations, which may significantly contribute to the

  4. Big mountains but small barriers: Population genetic structure of the Chinese wood frog (Rana chensinensis in the Tsinling and Daba Mountain region of northern China

    Directory of Open Access Journals (Sweden)

    Li Cheng

    2009-04-01

    Full Text Available Abstract Background Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Results Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. Conclusion The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high

  5. Turbulence and Araki-Woods factors

    DEFF Research Database (Denmark)

    Sasyk, R.; Törnquist, A.; Törnquist, Asger Dag

    2010-01-01

    Using Baire category techniques we prove that Araki-Woods factors are not classifiable by countable structures. As a result, we obtain a far reaching strengthening as well as a new proof of the well-known theorem of Woods that the isomorphism problem for ITPFI factors is not smooth. We derive...

  6. 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...

  7. Heating and ignition of small wood cylinders

    Science.gov (United States)

    Wallace L. Fons

    1950-01-01

    The literature provides limited information on the time of ignition of wood under conditions of rapid heating such as occur in forest and structure fires. An investigation was made of ease of ignition as affected by such physical properties of wood as initial temperature, size, and moisture content and by temperature of ambient gas or rate of heating. Temperature-time...

  8. 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.

  9. On the influence of load variations on lifetime and strength of wood

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    2006-01-01

    To days recommendations for probability and reliability analysis of wood structures do not fully recognize the influence of wood microstructure and creep on the mechanical behavior of wood. As a consequence, certain important features in wood design cannot be considered properly. Ignoring the bas...... history on recycle-strength (residual strength). It is demonstrated in this paper, how the problems just mentioned can be solved from respecting wood as a damaged viscoelastic material, meaning that wood is a cracked (damaged) material with creep....

  10. 77 FR 28519 - Test Procedure Guidance for Room Air Conditioners, Residential Dishwashers, and Residential...

    Science.gov (United States)

    2012-05-15

    ... Guidance for Room Air Conditioners, Residential Dishwashers, and Residential Clothes Washers: Public... procedures for room air conditioners, residential dishwashers, and residential clothes washers. DATES: DOE...'s existing test procedures for residential room air conditioners, residential dishwashers, and...

  11. PENGARUH UMUR POHON, BONITA DAN POSISI AKSIAL BATANG TERHADAP STRUKTUR MAKROSKOPIS DAN KUALITAS KAYU JATI SEBAGAI BAHAN FURNITUR (Effect of Tree Age, Site Quality Index and Trunk Axial Position on Macroscopic Structure and Quality of Teak Wood

    Directory of Open Access Journals (Sweden)

    Yustinus Suranto

    2015-03-01

    is an alternative solution of limited raw materials faced by furniture industry. Young wood tends to have a low-quality wood. One element for measuring wood quality is wood macroscopic structure properties. This study was aimed to determine the effect of tree age, site quality index and axial stem position on wood structures and wood quality. Thirty-six young teak trees were harvested on forest areas of Kendal Forest District, Central Java Province. Three disks were taken from each trunk, namely from the butt, middle and upper parts. Heartwood proportion and annual ring dimensions were measured based on natural color difference by using millimeter grid apparatus. Data were analyzed by using variance analysis arranged in blocked factorial and further testing were performed by using HSD Duncan. Wood quality was analyzed using determinant method which elaborated based on Z norm curve. Results showed that interaction of three factors did not affect on heart-wood proportion and growth ring dimensions. Interaction of age classes and site quality index influence significantly on heart-wood proportion and growth ring dimensions. Stem axial position significantly affects on heart-wood proportion and very significantly effect on growth ring dimensions. The lower wood position, the higher heart-wood proportion and the wider growth ring dimensions. Interaction of three factors namely class age V, site quality index 4 and middle trunk position has a highest wood quality, namely class 2, but interaction of age class V, site quality index 3 and top trunk has the lowest one, namely class 4. The use of wood-based quality will maximize the value and increase the product lifespan, thereby reducing the intensity of logging and become more environmental friendly.

  12. 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.

  13. Chapter 08: Comments on, and additional information for, wood identification

    Science.gov (United States)

    Alex C. Wiedenhoeft

    2011-01-01

    This manual has described the theory of identification (Chapter 1), the botanical basis of wood structure (Chapter 2), the use of a hand lens (Chapter 3), how to use cutting tools to prepare wood for observation with a lens (Chapter 4), and the characters used in hand lens wood identification (Chapter 5) before leading you through an identification key (Chapter 6) and...

  14. The wood anatomy of Gardenieae, Ixoreae and Mussaendeae (Rubiaceae)

    NARCIS (Netherlands)

    Koek-Noorman, Jifke

    1972-01-01

    The tribe Gardenieae in the restricted delimitation proposed by Bremekamp and Verdcourt is wood anatomically homogeneous. The genera of the Ixoreae studied by me also agree with each other in wood structure. Within the tribe Mussaendeae in the delimitation accepted by Schumann the wood anatomy shows

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Rocio Astrid BERNAL

    2011-09-01

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

  17. Effect of activation on the porous structure and the strain and strength properties of beech wood biocarbon

    Science.gov (United States)

    Shpeizman, V. V.; Orlova, T. S.; Spitsyn, A. A.; Ponomarev, D. A.; Bogdanovich, N. I.; Martinez-Fernández, J.

    2017-01-01

    The effect of activation on the size, specific volume, and surface area of pores in a monolithic biomorphic material obtained by carbonization of beech wood is studied. It is shown that under optimal activation mode with a steam heated to 970°C, the total pore volume and surface, determined by adsorption curves, increased by 20 and 18 times, respectively. With the use of high-precision interferometric procedure, strain curves are obtained under uniaxial compression with a stepwise loading, and the strain rate is measured with a step of moving of 325 nm for activated and nonactivated samples. Despite an increase in porosity, the strength and maximum deformation of the samples do not decrease. The behavior of the strain rate jumps is analyzed in the micro- and nanometer range. It is shown that the maximum size of the micrometer jumps (4 μm) correlates well with the average size of the possible strain area in the samples (the average distance between the pores of small size), and the minimum dimensions of the strain jumps are close to the size of mesopores. Assessment of the strain change and its rate upon activation indicates that the effect of activation on the strain and strength characteristics is defined by nanometer defects, the most likely of which are microand mesopores.

  18. Wood cell-wall structure requires local 2D-microtubule disassembly by a novel plasma membrane-anchored protein.

    Science.gov (United States)

    Oda, Yoshihisa; Iida, Yuki; Kondo, Yuki; Fukuda, Hiroo

    2010-07-13

    Plant cells have evolved cortical microtubules, in a two-dimensional space beneath the plasma membrane, that regulate patterning of cellulose deposition. Although recent studies have revealed that several microtubule-associated proteins facilitate self-organization of transverse cortical microtubules, it is still unknown how diverse patterns of cortical microtubules are organized in different xylem cells, which are the major components of wood. Using our newly established in vitro xylem cell differentiation system, we found that a novel microtubule end-tracking protein, microtubule depletion domain 1 (MIDD1), was anchored to distinct plasma membrane domains and promoted local microtubule disassembly, resulting in pits on xylem cell walls. The introduction of RNA interference for MIDD1 resulted in the failure of local microtubule depletion and the formation of secondary walls without pits. Conversely, the overexpression of MIDD1 reduced microtubule density. MIDD1 has two coiled-coil domains for the binding to microtubules and for the anchorage to plasma membrane domains, respectively. Combination of the two coils caused end tracking of microtubules during shrinkage and suppressed their rescue events. Our results indicate that MIDD1 integrates spatial information in the plasma membrane with cortical microtubule dynamics for determining xylem cell wall pattern. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. 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.

  20. 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)

  1. 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 ...

  2. Wood's lamp examination

    Science.gov (United States)

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

  3. Wood's lamp illumination (image)

    Science.gov (United States)

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

  4. 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 ...

  5. Fabrication and Performance of a Glue-Pressed Engineered Honeycomb Bamboo (GPEHB Structure with Finger-jointed Ends as a Potential Substitute for Wood Lumber

    Directory of Open Access Journals (Sweden)

    Jianbo Zhou

    2015-04-01

    Full Text Available With the increasing scarcity of wood as a natural resource, bamboo has become a popular substitute for wood. The present work developed a high-strength original state multi-reorganization material (GPEHB, without the use of a hot press or traditional assembly. The original bamboo units were polygonized into outer contours and milled into finger-joints on each ending. The GPEHB was organized and assembled under an external press, using industrial adhesives. The mechanical properties and thermal insulation of GPEHB were characterized. Moreover, the overall GPEHB unit bending strength was 73.15 MPa, and the parallel-to-grain compression was 55.22 MPa (higher than that of Pinus sylvestris lumber, though less than that of glued laminated bamboo. The GPEHB unit overall density was 0.24 g/cm³, 76% lower than that of glued laminated bamboo, and 50% lower than Pinus sylvestris lumber. The compressive strength of GPEHB (7 units was 170.5 kN, while the compressive strength of GPEHB for 14 units was 493.5 kN, which meet the requirements of GB 50005 (2003. The bending strength of GPEHB 7 units was 12 kN, while that of 14 units was 37 kN. The heat conductivity coefficient for GPEHB was 0.25 W/mK, which is better than concrete and steel. The GPEHB has taken full advantage of its honeycomb-structured material, which allows it to avoid stress concentration in the regular polygonal corners.

  6. Non_standard Wood

    DEFF Research Database (Denmark)

    Tamke, Martin

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

  7. Factor Structure, Reliability and Measurement Invariance of the Alberta Context Tool and the Conceptual Research Utilization Scale, for German Residential Long Term Care

    Science.gov (United States)

    Hoben, Matthias; Estabrooks, Carole A.; Squires, Janet E.; Behrens, Johann

    2016-01-01

    We translated the Canadian residential long term care versions of the Alberta Context Tool (ACT) and the Conceptual Research Utilization (CRU) Scale into German, to study the association between organizational context factors and research utilization in German nursing homes. The rigorous translation process was based on best practice guidelines for tool translation, and we previously published methods and results of this process in two papers. Both instruments are self-report questionnaires used with care providers working in nursing homes. The aim of this study was to assess the factor structure, reliability, and measurement invariance (MI) between care provider groups responding to these instruments. In a stratified random sample of 38 nursing homes in one German region (Metropolregion Rhein-Neckar), we collected questionnaires from 273 care aides, 196 regulated nurses, 152 allied health providers, 6 quality improvement specialists, 129 clinical leaders, and 65 nursing students. The factor structure was assessed using confirmatory factor models. The first model included all 10 ACT concepts. We also decided a priori to run two separate models for the scale-based and the count-based ACT concepts as suggested by the instrument developers. The fourth model included the five CRU Scale items. Reliability scores were calculated based on the parameters of the best-fitting factor models. Multiple-group confirmatory factor models were used to assess MI between provider groups. Rather than the hypothesized ten-factor structure of the ACT, confirmatory factor models suggested 13 factors. The one-factor solution of the CRU Scale was confirmed. The reliability was acceptable (>0.7 in the entire sample and in all provider groups) for 10 of 13 ACT concepts, and high (0.90–0.96) for the CRU Scale. We could demonstrate partial strong MI for both ACT models and partial strict MI for the CRU Scale. Our results suggest that the scores of the German ACT and the CRU Scale for nursing

  8. 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....

  9. 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

  10. 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...

  11. Request for wood samples

    NARCIS (Netherlands)

    NN,

    1977-01-01

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

  12. Application of molecular genetic methods for identification of wood-decaying fungi in wood constructions

    Directory of Open Access Journals (Sweden)

    Elena Bobeková

    2008-01-01

    Full Text Available The aim of the paper is to evaluate the utilization of molecular biology methods for detection of wood decaying fungi directly from decomposed wood using a commercial DNA extraction kit developed for soil substrates (PowerSoil™ DNA isolation kit. The experiment based on dry rot fungus (Serpula lacrymans detection from inoculated wooden pieces under laboratory conditions was followed by field detection of wood-decaying fungi from wood structures on building constructions. Fungal DNA was identified using the PCR–based methods including species-specific PCR and sequencing of amplified ITS region of ribosomal DNA.

  13. Biocentricity and economy of scale : hypothesis (and product) testing when wood is a part of an experimental system evaluating durability

    Science.gov (United States)

    Alex C. Wiedenhoeft

    2009-01-01

    Wood is a biological material, and its structure and organization are relicts of its biogenesis. From the hydrogen bonding of water molecules in the cell wall to extractives bleeding from knots in siding, the characteristics and behavior of wood are derived from its biological origin; this is my unashamedly biocentric view of wood structure. The structure of wood...

  14. Chapter 6: Above Ground Deterioration of Wood and Wood-Based Materials

    Science.gov (United States)

    Grant Kirker; Jerrold Winandy

    2014-01-01

    Wood as a material has unique properties that make it ideal for above ground exposure in a wide range of structural and non-strucutral applications. However, no material is without limitations. Wood is a bio-polymer which is subject to degradative processes, both abiotic and biotic. This chapter is a general summary of the abiotic and biotic factors that impact service...

  15. In-home performance of residential cordwood stoves

    International Nuclear Information System (INIS)

    Houck, J.E.; Barnett, S.G.; Roholt, R.B.

    1991-01-01

    The air quality impacts of residential cordwood stoves have been of concern to regulators, energy planners, and members of the woodstove industry. In addition, the reliability of laboratory certification emission values in predicting 'real world' emissions has been questioned. In response to these concerns, particulate emissions from residential cordwood stoves under actual in-home use have been measured for 5 heating seasons as part of 12 separate studies in Oregon, New York, Vermont, and the Yukon Territory. Monitoring was conducted using an automated emission sampler (AES) system. The system has been deployed in nearly 100 individual homes. Typically, emissions from several 1-week-long integrated sampling periods over the course of the heating season were measured with the AES system at each home. Particulate emission rates in grams of particles per hour of stove operation, grams of particles per kilogram of dry wood burned, and grams of particles per million Joules were calculated. Ancillary data provided by the studies included wood burn rates, homeowner wood loading patterns, wood moisture content and species, hours of operation of auxiliary heating appliances in the study homes, room ambient, flue gas, catalyst, and pre-catalyst temperatures, and hours of catalyst operation. Conventional stoves, high-technology non-catalytic stoves, catalytic stoves, and stoves equipped with retrofit catalytic devices have been studied. In addition to the 12 cordwood stove studies, the AES system has been used in 2 pellet stove studies and 1 fireplace study

  16. Factors affecting sodium hypochlorite extraction of CCA from treated wood.

    Science.gov (United States)

    Gezer, E D; Cooper, P A

    2009-12-01

    Significant amounts of chromated copper arsenate (CCA) treated wood products, such as utility poles and residential construction wood, remain in service. There is increasing public concern about environmental contamination from CCA-treated wood when it is removed from service for reuse or recycling, placed in landfills or burned in commercial incinerators. In this paper, we investigated the effects of time, temperature and sodium hypochlorite concentration on chromium oxidation and extraction of chromated copper arsenate from CCA-treated wood (Type C) removed from service. Of the conditions evaluated, reaction of milled wood with sodium hypochlorite for one hour at room temperature followed by heating at 75 degrees C for two hours gave the highest extraction efficiency. An average of 95% Cr, 99% Cu and 96% As could be removed from CCA-treated, milled wood by this process. Most of the extracted chromium was oxidized to the hexavalent state and could therefore be recycled in a CCA treating solution. Sodium hypochlorite extracting solutions could be reused several times to extract CCA components from additional treated wood samples.

  17. Predictive Modeling of Black Spruce (Picea mariana (Mill. B.S.P. Wood Density Using Stand Structure Variables Derived from Airborne LiDAR Data in Boreal Forests of Ontario

    Directory of Open Access Journals (Sweden)

    Bharat Pokharel

    2016-12-01

    Full Text Available Our objective was to model the average wood density in black spruce trees in representative stands across a boreal forest landscape based on relationships with predictor variables extracted from airborne light detection and ranging (LiDAR point cloud data. Increment core samples were collected from dominant or co-dominant black spruce trees in a network of 400 m2 plots distributed among forest stands representing the full range of species composition and stand development across a 1,231,707 ha forest management unit in northeastern Ontario, Canada. Wood quality data were generated from optical microscopy, image analysis, X-ray densitometry and diffractometry as employed in SilviScan™. Each increment core was associated with a set of field measurements at the plot level as well as a suite of LiDAR-derived variables calculated on a 20 × 20 m raster from a wall-to-wall coverage at a resolution of ~1 point m−2. We used a multiple linear regression approach to identify important predictor variables and describe relationships between stand structure and wood density for average black spruce trees in the stands we observed. A hierarchical classification model was then fitted using random forests to make spatial predictions of mean wood density for average trees in black spruce stands. The model explained 39 percent of the variance in the response variable, with an estimated root mean square error of 38.8 (kg·m−3. Among the predictor variables, P20 (second decile LiDAR height in m and quadratic mean diameter were most important. Other predictors describing canopy depth and cover were of secondary importance and differed according to the modeling approach. LiDAR-derived variables appear to capture differences in stand structure that reflect different constraints on growth rates, determining the proportion of thin-walled earlywood cells in black spruce stems, and ultimately influencing the pattern of variation in important wood quality attributes

  18. European wood-pastures in transition

    DEFF Research Database (Denmark)

    Wood-pastures are important elements of European cultural identity and have an exceptional ecological value, yet they are in decline all over Europe. The structure of wood-pastures is strongly influenced by grazing and multiple other land uses and by local and regional environmental conditions....... This book examines the diverse expressions of wood-pastures across Europe. It provides a new perspective, using a social-ecological framework to explore social and ecological values, governing institutions, threats and conservation approaches. It explores the major drivers of decline, which are shown...

  19. Particulate and gaseous emissions from residential biomass combustion

    International Nuclear Information System (INIS)

    Boman, Christoffer

    2005-04-01

    Biomass is considered to be a sustainable energy source with significant potentials for replacing electricity and fossil fuels, not at least in the residential sector. However, present wood combustion is a major source of ambient concentrations of hydrocarbons (e.g. VOC and PAH) and particulate matter (PM) and exposure to these pollutants have been associated with adverse health effects. Increased focus on combustion related particulate emissions has been seen concerning the formation, characteristics and implications to human health. Upgraded biomass fuels (e.g. pellets) provide possibilities of more controlled and optimized combustion with less emission of products of incomplete combustion (PICs). For air quality and health impact assessments, regulatory standards and evaluations concerning residential biomass combustion, there is still a need for detailed emission characterization and quantification when using different fuels and combustion techniques. This thesis summarizes the results from seven different papers. The overall objective was to carefully and systematically study the emissions from residential biomass combustion with respect to: i) experimental characterization and quantification, ii) influences of fuel, appliance and operational variables and iii) aspects of ash and trace element transformations and aerosol formation. Special concern in the work was on sampling, quantification and characterization of particulate emissions using different appliances, fuels and operating procedures. An initial review of health effects showed epidemiological evidence of potential adverse effect from wood smoke exposure. A robust whole flow dilution sampling set-up for residential biomass appliances was then designed, constructed and evaluated, and subsequently used in the following emission studies. Extensive quantifications and characterizations of particulate and gases emissions were performed for residential wood and pellet appliances. Emission factor ranges for

  20. Laboratory Investigation on Compressive Strength and Micro-structural Features of Foamed Concrete with Addition of Wood Ash and Silica Fume as a Cement Replacement

    Directory of Open Access Journals (Sweden)

    Othuman Mydin M.A.

    2014-01-01

    Full Text Available Wood Ash (WA and Silica Fume (SF exhibit good cementation properties and have great potential as supplementary binder materials for the concrete production industry. This study will focus on enhancing the micro-structural formation and compressive strength of foamed concrete with the addition of WA and SF. A total of 3 mixes were prepared with the addition of WA and SF at various cement replacement levels by total binder weight. For this particular study, the combination of WA (5%, 10%, and 15% by binder weight and SF (5%, 10%, and 15% by binder weight were utilized as supplementary binder materials to produce foamed concrete mixes. As was made evident from micrographs obtained in the study, the improvement observed in the compressive strength of the foamed concrete was due to a significant densification in the microstructure of the cement paste matrix in the presence of WA and SF hybrid supplementary binders. Experimental results indicated that the combination of 15% SF and 5% WA by binder weight had a more substantial influence on the compressive strength of foamed concrete compared to the control mix. Furthermore, the addition of WA and SF significantly prolonged the setting times of the blended cement paste of the foamed concrete.

  1. Residentialization of Public Spaces: Bratislava Example

    Science.gov (United States)

    Bacová, Andrea; Puškár, Branislav; Vráblová, Edita

    2017-10-01

    The housing estates in Bratislava saturated the housing needs of a large number of inhabitants who come after World War II to the city. Design of public spaces often did not have priority in the process of designing. The solutions for mentioned exterior spaces had been planned after blocks of flat realization, but many of them are not realized to this day. The article analyzes the example of the unrealized public spaces in existing housing estates Devinska Nova Ves and Petržalka (city districts of Bratislava) and offer practical solutions in relation to residencialization method. Residencialization of missing public places is an effective method of adding identities to settlements. It improves the quality of residential environment and public spaces. The main aim is to create better conditions for social activities in public areas, which are missing on the present. The research will be focused on the examination of the urban, cultural and construction potential of the existing residential enviroment in Bratislava. The main aim of residentialization is not only to enhance the quality of spatial and building structures in the selected residential area and maintain long-term sustainability in the pertinent programme area, but mainly to improve the quality of living for the residents. The outputs of the project are proposals and practical procedures developed with regard to planning documents for local municipal authorities and regional organizations. The solutions will have a positive impact on the enhancement of the quality of public spaces, attractive social activities and of a conceptual link - residentialization.

  2. Condition assessment and strengthening of residential units

    Directory of Open Access Journals (Sweden)

    Tatheer Zahra

    2014-01-01

    Full Text Available About 40, ground plus one (G+1 residential units were designed using a hybrid structural framing system (RC frame and load bearing walls. A few months after the completion of the ground floor of the residential units, cracks appeared at several locations in the structure. Field and Laboratory testing was conducted to ascertain the in situ strength of concrete and steel reinforcement. The results of the experimental work were used in the analytical ETABS model for the structural stability calculations. The results indicated that residential units were marginally safe in the existing condition (completed ground floor, but the anticipated construction of the floor above the ground floor (G+1 could not be carried out as the strength of the structural system was inadequate. To increase the safety of existing ground floor and to provide the option of the construction of one floor above, rehabilitation and strengthening design was performed. The proposed strengthening design made use of welded wire fabric (WWF and carbon fibre reinforced polymer (CFRP laminates/sheets for the strengthening of walls, columns and slabs. The residential units will be strengthened in the near future.

  3. 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...

  4. 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.

  5. 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

  6. 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...

  7. 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....

  8. Energy Performance of a Light Wood-Timber Structured House in the Severely Cold Region of China

    Directory of Open Access Journals (Sweden)

    Meng Zhen

    2018-05-01

    Full Text Available The purpose of the study was to determine the energy performance of a timber structured house built in Harbin, a severely cold region of China. The research team conducted a field test on the house that lasted three months (15 January–15 April 2008. The test included the winter heating energy consumption, average indoor temperature and relative humidity, building heat storage capacity, heat transfer coefficient of the wall, total air volume of air-conditioning system, etc. The test results showed that the total heating was calculated to be 73,240.59 MJ in winter. Thermal imaging tests were carried out on the house and found no obvious thermal defects such as thermal bridges. In conclusion, the timber structured house has a good level of building energy conservation and would provide a good exemplary for green building design and construction in similar severely cold regions in the world.

  9. Family ties and residential locations

    NARCIS (Netherlands)

    Mulder, C.H.; Cooke, T.J.

    2009-01-01

    In this paper, and in the Special Issue it introduces, the focus is on the role of family ties in residential location choice and, conversely, the role of residential locations in maintaining family ties. Not only do events in the nuclear family trigger residential relocations, but nearby family

  10. Preparation and applications of wood-polyester composites

    International Nuclear Information System (INIS)

    Czvikovszky, T.

    1982-01-01

    Optimum processing parameters were searched for the pilot-scale production of wood-polyester composites by irradiation of resin-impregnated wood material. The radiation initiation of the following systems were examined in wood and without wood matrix: methyl methacrylate, mixture of styrene and acrylonitryle, and their combination with unsaturated polyester. In the most cases the over-all rate of the complete polymerization process in wood matrix is proportional to the square root of the initiation rate. The parameters of the radiation technology of wood-polyester composites have been determined, using 260 TBq (7 kCi) 60 Co radiation source. A pilot plant has been constructed using an underwater irradiation system of 1.85 PBq (50 kCi) 60 Co. The successful production rate of 200 kg wood-polyester composite per day, as well as the application tests have demonstrated the technical feasibility of this new structural material. (author)

  11. 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....

  12. 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

  13. Modelling and forecasting Turkish residential electricity demand

    International Nuclear Information System (INIS)

    Dilaver, Zafer; Hunt, Lester C

    2011-01-01

    This research investigates the relationship between Turkish residential electricity consumption, household total final consumption expenditure and residential electricity prices by applying the structural time series model to annual data over the period from 1960 to 2008. Household total final consumption expenditure, real energy prices and an underlying energy demand trend are found to be important drivers of Turkish residential electricity demand with the estimated short run and the long run total final consumption expenditure elasticities being 0.38 and 1.57, respectively, and the estimated short run and long run price elasticities being -0.09 and -0.38, respectively. Moreover, the estimated underlying energy demand trend, (which, as far as is known, has not been investigated before for the Turkish residential sector) should be of some benefit to Turkish decision makers in terms of energy planning. It provides information about the impact of past policies, the influence of technical progress, the impacts of changes in consumer behaviour and the effects of changes in economic structure. Furthermore, based on the estimated equation, and different forecast assumptions, it is predicted that Turkish residential electricity demand will be somewhere between 48 and 80 TWh by 2020 compared to 40 TWh in 2008. - Research highlights: → Estimated short run and long run expenditure elasticities of 0.38 and 1.57, respectively. → Estimated short run and long run price elasticities of -0.09 and -0.38, respectively. → Estimated UEDT has increasing (i.e. energy using) and decreasing (i.e. energy saving) periods. → Predicted Turkish residential electricity demand between 48 and 80 TWh in 2020.

  14. GREEN RETROFITTING RESIDENTIAL BUILDINGS

    Science.gov (United States)

    When compared with the rest of the world, the United States consumes a disproportionately large amount of energy and is a major source of greenhouse gases from fossil fuel combustion. As much as two thirds of U.S. electricity production is consumed by residential and commerci...

  15. Residential Mechanical Precooling

    Energy Technology Data Exchange (ETDEWEB)

    German, a. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2014-12-01

    This research conducted by the Alliance for Residential Building Innovation team evaluated mechanical air conditioner pre-cooling strategies in homes throughout the United States. EnergyPlus modeling evaluated two homes with different performance characteristics in seven climates. Results are applicable to new construction homes and most existing homes built in the last 10 years, as well as fairly efficient retrofitted homes.

  16. Factors affecting wood energy consumption by U.S. households

    Science.gov (United States)

    Nianfu Song; Francisco X. Aguilar; Stephen R. Shifley; Michael E. Goerndt

    2012-01-01

    About 23% of energy derived from woody sources in the U.S. was consumed by households, of which 70% was used by households in rural areas in 2005. We investigated factors affecting household-level wood energy consumption in the four continental U.S. regions using data from the U.S. Residential Energy Consumption Survey. To account for a large number of zero...

  17. Penetration and Effectiveness of Micronized Copper in Refractory Wood Species.

    Science.gov (United States)

    Civardi, Chiara; Van den Bulcke, Jan; Schubert, Mark; Michel, Elisabeth; Butron, Maria Isabel; Boone, Matthieu N; Dierick, Manuel; Van Acker, Joris; Wick, Peter; Schwarze, Francis W M R

    2016-01-01

    The North American wood decking market mostly relies on easily treatable Southern yellow pine (SYP), which is being impregnated with micronized copper (MC) wood preservatives since 2006. These formulations are composed of copper (Cu) carbonate particles (CuCO3·Cu(OH)2), with sizes ranging from 1 nm to 250 μm, according to manufacturers. MC-treated SYP wood is protected against decay by solubilized Cu2+ ions and unreacted CuCO3·Cu(OH)2 particles that successively release Cu2+ ions (reservoir effect). The wood species used for the European wood decking market differ from the North American SYP. One of the most common species is Norway spruce wood, which is poorly treatable i.e. refractory due to the anatomical properties, like pore size and structure, and chemical composition, like pit membrane components or presence of wood extractives. Therefore, MC formulations may not suitable for refractory wood species common in the European market, despite their good performance in SYP. We evaluated the penetration effectiveness of MC azole (MCA) in easily treatable Scots pine and in refractory Norway spruce wood. We assessed the effectiveness against the Cu-tolerant wood-destroying fungus Rhodonia placenta. Our findings show that MCA cannot easily penetrate refractory wood species and could not confirm the presence of a reservoir effect.

  18. Protection of Wood from Microorganisms by Laccase-Catalyzed Iodination

    Science.gov (United States)

    Engel, J.; Thöny-Meyer, L.; Schwarze, F. W. M. R.; Ihssen, J.

    2012-01-01

    In the present work, Norway spruce wood (Picea abies L.) was reacted with a commercial Trametes versicolor laccase in the presence of potassium iodide salt or the phenolic compounds thymol and isoeugenol to impart an antimicrobial property to the wood surface. In order to assess the efficacy of the wood treatment, a leaching of the iodinated and polymerized wood and two biotests including bacteria, a yeast, blue stain fungi, and wood decay fungi were performed. After laccase-catalyzed oxidation of the phenols, the antimicrobial effect was significantly reduced. In contrast, the enzymatic oxidation of iodide (I−) to iodine (I2) in the presence of wood led to an enhanced resistance of the wood surface against all microorganisms, even after exposure to leaching. The efficiency of the enzymatic wood iodination was comparable to that of a chemical wood preservative, VP 7/260a. The modification of the lignocellulose by the laccase-catalyzed iodination was assessed by the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The intensities of the selected lignin-associated bands and carbohydrate reference bands were analyzed, and the results indicated a structural change in the lignin matrix. The results suggest that the laccase-catalyzed iodination of the wood surface presents an efficient and ecofriendly method for wood protection. PMID:22865075

  19. X-ray initiated polymerization of wood impregnants

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, Marshall R.; Galloway, Richard A. [IBA Industrial, Inc., Edgewood, NY (United States); Berejka, Anthony J. [Ionicorp, Huntington, NY 11743 (United States)], E-mail: berejka@msn.com; Montoney, Daniel [Strathmore Products, Syracuse, NY (United States); Driscoll, Mark; Smith, Leonard; Scott Larsen, L. [State University of New York, SUNY-ESF, Syracuse, NY (United States)

    2009-07-15

    X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

  20. X-ray initiated polymerization of wood impregnants

    International Nuclear Information System (INIS)

    Cleland, Marshall R.; Galloway, Richard A.; Berejka, Anthony J.; Montoney, Daniel; Driscoll, Mark; Smith, Leonard; Scott Larsen, L.

    2009-01-01

    X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

  1. Life-cycle energy of residential buildings in China

    International Nuclear Information System (INIS)

    Chang, Yuan; Ries, Robert J.; Wang, Yaowu

    2013-01-01

    In the context of rapid urbanization and new construction in rural China, residential building energy consumption has the potential to increase with the expected increase in demand. A process-based hybrid life-cycle assessment model is used to quantify the life-cycle energy use for both urban and rural residential buildings in China and determine the energy use characteristics of each life cycle phase. An input–output model for the pre-use phases is based on 2007 Chinese economic benchmark data. A process-based life-cycle assessment model for estimating the operation and demolition phases uses historical energy-intensity data. Results show that operation energy in both urban and rural residential buildings is dominant and varies from 75% to 86% of life cycle energy respectively. Gaps in living standards as well as differences in building structure and materials result in a life-cycle energy intensity of urban residential buildings that is 20% higher than that of rural residential buildings. The life-cycle energy of urban residential buildings is most sensitive to the reduction of operational energy intensity excluding heating energy which depends on both the occupants' energy-saving behavior as well as the performance of the building itself. -- Highlights: •We developed a hybrid LCA model to quantify the life-cycle energy for urban and rural residential buildings in China. •Operation energy in urban and rural residential buildings is dominant, varying from 75% to 86% of life cycle energy respectively. •Compared with rural residential buildings, the life-cycle energy intensity of urban residential buildings is 20% higher. •The life-cycle energy of urban residential buildings is most sensitive to the reduction of daily activity energy

  2. Emissions from residential combustion considering end-uses and spatial constraints: Part I, methods and spatial distribution

    Science.gov (United States)

    Winijkul, Ekbordin; Fierce, Laura; Bond, Tami C.

    2016-01-01

    This study describes a framework to attribute national-level atmospheric emissions in the year 2010 from the residential sector, one of the largest energy-related sources of aerosol emissions. We place special emphasis on end-uses, dividing usage into cooking, heating, lighting, and others. This study covers regions where solid biomass fuel provides more than 50% of total residential energy: Latin America, Africa, and Asia (5.2 billion people in 2010). Using nightlight data and population density, we classify five land types: urban, electrified rural with forest access, electrified rural without forest access, non-electrified rural with forest access, and non-electrified rural without forest access. We then apportion national-level residential fuel consumption among all land-types and end-uses, and assign end-use technologies to each combination. The resulting calculation gives spatially-distributed emissions of particulate matter, black carbon, organic carbon, nitrogen oxides, methane, non-methane hydrocarbons, carbon monoxide, and carbon dioxide. Within this study region, about 13% of the energy is consumed in urban areas, and 45% in non-urban land near forests. About half the energy is consumed in land without access to electricity. Cooking accounts for 54% of the consumption, heating for 9%, and lighting only 2%, with unidentified uses making up the remainder. Because biofuel use is assumed to occur preferentially where wood is accessible and electricity is not, our method shifts emissions to land types without electrification, compared with previous methods. The framework developed here is an important first step in acknowledging the role of household needs and local constraints in choosing energy provision. Although data and relationships described here need further development, this structure offers a more physically-based understanding of residential energy choices and, ultimately, opportunities for emission reduction.

  3. 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).

  4. Residential damage in an area of underground coal mining

    International Nuclear Information System (INIS)

    Padgett, M.F.

    1988-01-01

    In order to estimate the potential for future subsidence-related residential damage, a statistical analysis of past residential damage in the Boulder-Weld, Colorado, coal field was performed. The objectives of this study were to assess the difference in damage severity and frequency between undermined and non-undermined areas, and to determine, where applicable, which mining factors significantly influence the severity and frequency of residential damage. The results of this study suggest that undermined homes have almost three times the risk of having some type of structural damage than do non-undermined homes. The study also indicated that both geologic factors, such as the ratio of sandstone/claystone in the overburden, and mining factors, such as the mining feature (room, pillar, entry, etc.), can significantly affect the severity of overlying residential damage. However, the results of this study are dependent on local conditions and should not be applied elsewhere unless the geologic, mining, and residential conditions are similar

  5. Analysis of a Residential Building Energy Consumption Demand Model

    Directory of Open Access Journals (Sweden)

    Meng Liu

    2011-03-01

    Full Text Available In order to estimate the energy consumption demand of residential buildings, this paper first discusses the status and shortcomings of current domestic energy consumption models. Then it proposes and develops a residential building energy consumption demand model based on a back propagation (BP neural network model. After that, taking residential buildings in Chongqing (P.R. China as an example, 16 energy consumption indicators are introduced as characteristics of the residential buildings in Chongqing. The index system of the BP neutral network prediction model is established and the multi-factorial BP neural network prediction model of Chongqing residential building energy consumption is developed using the Cshap language, based on the SQL server 2005 platform. The results obtained by applying the model in Chongqing are in good agreement with actual ones. In addition, the model provides corresponding approximate data by taking into account the potential energy structure adjustments and relevant energy policy regulations.

  6. Disintegration of beech wood char during thermal conversion

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    In the present work the processes occurring in the structures of slowly pyrolysed beech wood char during thermal gasification have been investigated. Emphasis was put on physical changes and gas transport properties during conversion. The highly anisotropic structure of wood was preserved in its ...

  7. Fire resistance of wood members with directly applied protection

    Science.gov (United States)

    Robert H. White

    2009-01-01

    Fire-resistive wood construction is achieved either by having the structural elements be part of fire-rated assemblies or by using elements of sufficient size that the elements themselves have the required fire-resistance ratings. For exposed structural wood elements, the ratings in the United States are calculated using either the T.T. Lie method or the National...

  8. 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.)

  9. 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...

  10. 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 (...

  11. 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...

  12. 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

  13. 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…

  14. 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.)

  15. 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...

  16. 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

  17. Effects of wood preservative leachates from docks

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, P.H.; Van Dolah, R.F.; Bobo, M.Y.; Mathews, T.D. [South Carolina Marine Resources Research Inst., Charleston, SC (United States)

    1994-12-31

    Recent evidence indicates that the wood preservative commonly used in dock pilings (chromated copper arsenate or CCA) is highly toxic to several estuarine organisms in laboratory experiments. Increasing demand for residential docks prompted a field study intended to complement these earlier laboratory investigations. Objectives of the study were to: (1) examine concentrations of Cu, Cr, and As in sediments and oysters from intertidal locations in several creeks with and without high densities of docks; (2) examine the bioaccumulation of wood preservative leachates by laboratory-reared oysters transferred to field sites near and distant from newly constructed docks; and (3) investigate the acute toxicity of wood preservative leachates for several species of estuarine fishes and invertebrates exposed to these compounds in the field. Preliminary results indicate that sediment concentrations of all three metals were well below ER-L levels reported by Long and Morgan at all but one dock site. In an ancillary study, 24h LC{sub 50} bioassays were performed using rotifers (Brachionus plicatilis) which were exposed to pore water from sediments in creeks with and without docks. Toxicities of bulk sediments from the same sites were examined using Microtox which measures decreases in bioluminescence of marine bacteria (Photobacterium phosphoreum) as a function of sediment concentration. Neither the rotifer nor the Microtox bioassays showed any significant differences in toxicity between creeks with and without docks.

  18. Energy wood. Part 2b: Wood pellets and pellet space-heating systems; Holzenergie Teil 2b: Holzpellets und Pelletheizungen / Energie du bois Partie 2b: Granules de bois et installations de chauffage a granules de bois

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T. [Verenum, Zuerich (Switzerland)

    2002-07-01

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

  19. Comparison of economic instruments to reduce PM_2_._5 from industrial and residential sources

    International Nuclear Information System (INIS)

    Mardones, Cristian; Saavedra, Andrés

    2016-01-01

    In the literature, it is possible to find different studies that compare economic instruments performance applied to the industrial sources regulation; however, evidence about pollution from residential sources is scarce. For this reason, the present study simulates and compares an emission permit system (EPS) and an ambient permit system (APS) when fine particulate matter pollution (PM_2_._5) is generated from industrial and residential sources. Thus, this research contributes to the spatial, economic and environmental assessment of industrial and residential emissions. The options to reduce pollution include replacement of heating devices in residential sources and installing end-of-pipe technologies in industrial sources. The results in terms of total cost and technological chosen options are similar under an APS and EPS for targets lesser to 80%. This is explained because it is more cost-effective to reduce emissions in residential sources than in industrial sources, and additionally, residential pollution has only local impact. However, some industrial sources should install abatement technologies for more demanding targets; in this case as industrial pollution are scattered in different areas, the total cost of an APS are lower than the total cost of an EPS. - Highlights: • The impact of wood burning on air quality can be significant in urban areas. • Residential and industrial sources in regulatory schemes to PM_2_._5 are analyzed. • Wood smoke pollution can be reduced by changing to more efficient heating devices. • Wood heater replacement is more cost-effective than abatement technologies. • The results are similar under APS and EPS for targets lesser to 80%.

  20. CONCERNING THE ELASTIC ORTHOTROPIC MODEL APPLIED TO WOOD ELASTIC PROPERTIES

    OpenAIRE

    Tadeu Mascia,Nilson

    2003-01-01

    Among the construction materials, wood reveals an orthotropic pattern, because of unique characteristics in its internal structure with three axes of wood biological directions (longitudinal, tangential and radial). elastic symmetry: longitudinal, tangential and radial, reveals an orthotropic pattern. The effect of grain angle orientation onin the elastic modulus constitutes the fundamental cause forof wood anisotropy. It is responsible for the greatest changes in the values of the constituti...

  1. Wood anatomy of the Euphorbiaceae, in particular of the subfamily Phyllanthoideae

    NARCIS (Netherlands)

    Mennega, Alberta M.W.

    1985-01-01

    The great variety in wood structure of the large family Euphorbiaceae makes it impossible to describe briefly a general wood pattern. Nevertheless, a more or less clear division into four anatomical groups can be made. A short overview is given of the wood structure of the uni-ovulate subfamilies

  2. 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...

  3. ASSESSING CHILDREN'S EXPOSURES TO THE WOOD PRESERVATIVE CCA (CHROMATED COPPER ARSENATE) ON TREATED PLAYSETS AND DECKS

    Science.gov (United States)

    Concerns have been raised regarding the safety of young children contacting arsenic and chromium residues while playing on and around Chromated Copper Arsenate (CCA) treated wood playground structures and decks. Although CCA registrants voluntarily canceled treated wood for re...

  4. Performance of Teak (Tectona grandis L.F) wood on exposure to ...

    African Journals Online (AJOL)

    Michael Horsfall

    surface splitting and checking. Its wood is therefore recommended for use as structural material in outdoor weather ... caused by UV radiation is the most damaging, however, the synergistic .... other tropical hard wood species. The effects of ...

  5. 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.

  6. Developments to the Sylvan stand structure model to describe wood quality changes in southern bottomland hardwood forests because of forest management

    Science.gov (United States)

    Ian R. Scott

    2009-01-01

    Growth models can produce a wealth of detailed information that is often very difficult to perceive because it is frequently presented either as summary tables, stand view or landscape view visualizations. We have developed new tools for use with the Sylvan model (Larsen 1994) that allow the analysis of wood-quality changes as a consequence of forest management....

  7. 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...

  8. Functional lignocellulosic materials prepared by ATRP from a wood scaffold

    Science.gov (United States)

    Cabane, Etienne; Keplinger, Tobias; Künniger, Tina; Merk, Vivian; Burgert, Ingo

    2016-01-01

    Wood, a natural and abundant source of organic polymers, has been used as a scaffold to develop novel wood-polymer hybrid materials. Through a two-step surface-initiated Atom Transfer Radical Polymerization (ATRP), the porous wood structure can be effectively modified with polymer chains of various nature. In the present study, polystyrene and poly(N-isopropylacrylamide) were used. As shown with various characterization techniques including confocal Raman microscopy, FTIR, and SEM/EDX, the native wood ultrastructure and features are retained and the polymer chains can be introduced deep within the wood, i.e. inside the wood cell walls. The physical properties of the new materials have been studied, and results indicate that the insertion of polymer chains inside the wood cell wall alters the intrinsic properties of wood to yield a hybrid composite material with new functionalities. This approach to the functionalization of wood could lead to the fabrication of a new class of interesting functional materials and promote innovative utilizations of the renewable resource wood. PMID:27506369

  9. 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...

  10. 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)

  11. Developing estimates of potential demand for renewable wood energy products in Alaska

    Science.gov (United States)

    Allen M. Brackley; Valerie A. Barber; Cassie Pinkel

    2010-01-01

    Goal three of the current U.S. Department of Agriculture, Forest Service strategy for improving the use of woody biomass is to help develop and expand markets for woody biomass products. This report is concerned with the existing volumes of renewable wood energy products (RWEP) that are currently used in Alaska and the potential demand for RWEP for residential and...

  12. Evaluating the natural durability of native and tropical wood species against Reticulitermes flavipes

    Science.gov (United States)

    R.A. Arango; F. Green; K. Hintz; R.B. Miller

    2004-01-01

    Environmental pressures to eliminate arsenate from wood preservatives has resulted in voluntary removal of CCA for residential applications in the United States. A new generation of copper organic preservatives has been formulated to replace CCA for decking and in-ground applications but there is no guarantee that these preservatives represent a permanent solution to...

  13. Changes of indoor climate by the adoption of retrofitted wood-burning stoves

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo; Jensen, Ole Michael; Tarelho, Luis A. C.

    2014-01-01

    More than 3 billion people in the world rely on local solid-fuels for domestic cooking and heating through inefficient combustion, causing indoor air pollution and overheating worldwide. Technological regimes were categorized in 18 popular stove models to describe how residential wood combustion ...

  14. Natural durability of tropical and native woods against termite damage by Reticulitermes flavipes (Kollar)

    Science.gov (United States)

    Rachel A. Arango; Frederick Green; Kristina Hintz; Patricia K. Lebow; Regis B. Miller

    2006-01-01

    Environmental pressure has resulted in voluntary removal of chromated copper arsenate (CCA) from wood preservatives in residential applications in the United States. A new generation of copper organic preservatives was formulated as replacements, but these preservatives may not provide a permanent solution to all related problems. Some of these issues include concern...

  15. Synchrotron applications in wood preservation and deterioration

    Science.gov (United States)

    Barbara L. Illman

    2003-01-01

    Several non-intrusive synchrotron techniques are being used to detect and study wood decay. The techniques use high intensity synchrotron-generated X-rays to determine the atomic structure of materials with imaging, diffraction, and absorption. Some of the techniques are X-ray absorption near edge structure (XANES), X-ray fluorescence spectroscopy (XFS), X-ray...

  16. Wood Stove Pollution in the Developed World: A Case to Raise Awareness Among Pediatricians.

    Science.gov (United States)

    Rokoff, Lisa B; Koutrakis, Petros; Garshick, Eric; Karagas, Margaret R; Oken, Emily; Gold, Diane R; Fleisch, Abby F

    2017-06-01

    Use of wood for residential heating is regaining popularity in developed countries. Currently, over 11 million US homes are heated with a wood stove. Although wood stoves reduce heating costs, wood smoke may adversely impact child health through the emission of gaseous and particulate air pollutants. Our purpose is to raise awareness of this environmental health issue among pediatricians. To summarize the state of the science, we performed a narrative review of articles published in PubMed and Web of Science. We identified 36 studies in developed countries that reported associations of household wood stove use and/or community wood smoke exposure with pediatric health outcomes. Studies primarily investigated respiratory outcomes, with no evaluation of cardiometabolic or neurocognitive health. Studies found community wood smoke exposure to be consistently associated with adverse pediatric respiratory health. Household wood stove use was less consistently associated with respiratory outcomes. However, studies of household wood stoves always relied on participant self-report of wood stove use, while studies of community wood smoke generally assessed air pollution exposure directly and more precisely in larger study populations. In most studies, important potential confounders, such as markers of socioeconomic status, were unaccounted for and may have biased results. We conclude that studies with improved exposure assessment, that measure and account for confounding, and that consider non-respiratory outcomes are needed. While awaiting additional data, pediatricians can refer patients to precautionary measures recommended by the US Environmental Protection Agency (EPA) to mitigate exposure. These include replacing old appliances with EPA-certified stoves, properly maintaining the stove, and using only dry, well-seasoned wood. In addition, several studies have shown mechanical air filters to effectively reduce wood stove pollution exposure in affected homes and

  17. Large-Scale Residential Demolition

    Science.gov (United States)

    The EPA provides resources for handling residential demolitions or renovations. This includes planning, handling harmful materials, recycling, funding, compliance assistance, good practices and regulations.

  18. A General Evaluation for Recycling Process of Impregnated Wood Removed From the Service

    Directory of Open Access Journals (Sweden)

    Cihat Taşçıoğlu

    2011-03-01

    Full Text Available Wood presevatives such as creosote, pentaclorophenol (PCP and chromated copper arsenate (CCA have been widely used over the years in order to extend wood products’ service life. CCA was known as most widely used wood preservative chemical in residendial and commercial applications world wide until 2004 volanteered phase out of the chemical from residential use bye the major manufacturers. Over the years CCA treated wood acuumulated in service reaching millions of cubic meters. But there is growing concern about the environmental impacts and increasing difficulty in disposing of treated wood products in many countries. Since disposal of CCA treated wood material poses greater problems than the other treated wood products due to heavy and toxic metal componets of CCA such as chromium and arsenic Traditional disposal methods like landfillig or incineration, both have negative environmental consequences. For that reason the increasing volume of CCA-treated wood products coming out of service requires alternative disposal methods and recycling techniques never tried before. The main purpose of this study, except for traditional methods like landfilling and incineration, is to evaluate the current alternative disposal and recycling methods for CCA treated wood removed from service.

  19. ASHRAE and residential ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.

    2003-10-01

    In the last quarter of a century, the western world has become increasingly aware of environmental threats to health and safety. During this period, people psychologically retreated away from outdoors hazards such as pesticides, smog, lead, oil spills, and dioxin to the seeming security of their homes. However, the indoor environment may not be healthier than the outdoor environment, as has become more apparent over the past few years with issues such as mold, formaldehyde, and sick-building syndrome. While the built human environment has changed substantially over the past 10,000 years, human biology has not; poor indoor air quality creates health risks and can be uncomfortable. The human race has found, over time, that it is essential to manage the indoor environments of their homes. ASHRAE has long been in the business of ventilation, but most of the focus of that effort has been in the area of commercial and institutional buildings. Residential ventilation was traditionally not a major concern because it was felt that, between operable windows and envelope leakage, people were getting enough outside air in their homes. In the quarter of a century since the first oil shock, houses have gotten much more energy efficient. At the same time, the kinds of materials and functions in houses changed in character in response to people's needs. People became more environmentally conscious and aware not only about the resources they were consuming but about the environment in which they lived. All of these factors contributed to an increasing level of public concern about residential indoor air quality and ventilation. Where once there was an easy feeling about the residential indoor environment, there is now a desire to define levels of acceptability and performance. Many institutions--both public and private--have interests in Indoor Air Quality (IAQ), but ASHRAE, as the professional society that has had ventilation as part of its mission for over 100 years, is the

  20. Electricity demand for South Korean residential sector

    International Nuclear Information System (INIS)

    Sa'ad, Suleiman

    2009-01-01

    This study estimates the electricity demand function for the residential sector of South Korea with the aim of examining the effects of improved energy efficiency, structural factors and household lifestyles on electricity consumption. In the study, time series data for the period from 1973 to 2007 is used in a structural time series model to estimate the long-term price and income elasticities and annual growth of underlying energy demand trend (UEDT) at the end of the estimation period. The result shows a long-term income elasticity of 1.33 and a long-term price elasticity of -0.27% with -0.93% as the percentage growth of UEDT at the end of the estimation period. This result suggests that, in order to encourage energy efficiency in the residential sector, the government should complement the market based pricing policies with non-market policies such as minimum energy efficiency standards and public enlightenment.

  1. Electricity demand for South Korean residential sector

    Energy Technology Data Exchange (ETDEWEB)

    Sa' ad, Suleiman [Surrey Energy Economics Centre (SEEC), Department of Economics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2009-12-15

    This study estimates the electricity demand function for the residential sector of South Korea with the aim of examining the effects of improved energy efficiency, structural factors and household lifestyles on electricity consumption. In the study, time series data for the period from 1973 to 2007 is used in a structural time series model to estimate the long-term price and income elasticities and annual growth of underlying energy demand trend (UEDT) at the end of the estimation period. The result shows a long-term income elasticity of 1.33 and a long-term price elasticity of -0.27% with -0.93% as the percentage growth of UEDT at the end of the estimation period. This result suggests that, in order to encourage energy efficiency in the residential sector, the government should complement the market based pricing policies with non-market policies such as minimum energy efficiency standards and public enlightenment. (author)

  2. An Analysis of the U.S. Wood Products Import Sector: Prospects for Tropical Wood Products Exporters

    Directory of Open Access Journals (Sweden)

    W.A.R.T.W. Bandara

    2012-10-01

    Full Text Available The U.S. has dramatically altered its wood product imports and exports during the past few years,and at present, it is the second largest wood product importer in the world. Hence, an understanding ofmarket structures, factors in selecting foreign suppliers, and the emphasis placed on environmentalissues/certification are critical to understand from the perspective of wood products importers in the U.S.This study provides an analysis of the U.S. wood products import sector with special emphasis on currentand future opportunities for tropical wood products exporters to the U.S. market.In this study, 158 wood products importers in the U.S. were surveyed using a mailingquestionnaire. The adjusted response rate was 40.6 percent. Results indicated that most of the respondentswere small to medium scale firms, but major importers of wood products. According to respondents,wood products to the U.S. mainly come from Brazil, Chile, and China. From the importers’ perspective,Brazilian wood products ranked first for its quality followed by wood products from Chile and Finland.Product quality, long term customer relationships, on-time delivery of orders, fair prices, and supplierreputation were the factors deemed important in selecting overseas suppliers. Majority of respondentswere importing certified wood products. FSC, SFI, and ISO 14000 were the mostly accepted certificationprograms. However, certification was not a major factor in foreign supplier selection criteria. Whenconsidered the U.S. wood products importers’ tendency to diversify their products and species imported,attractive opportunities exist for wood products suppliers from tropical countries.

  3. 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...

  4. In situ polymerization of polyaniline in wood veneers.

    Science.gov (United States)

    Trey, Stacy; Jafarzadeh, Shadi; Johansson, Mats

    2012-03-01

    The present study describes the possibility to polymerize aniline within wood veneers to obtain a semi-conducting material with solid wood acting as the base template. It was determined that it is possible to synthesize the intrinsically conductive polymer (ICP) polyaniline in situ within the wood structure of Southern yellow pine veneers, combining the strength of the natural wood structure with the conductivity of the impregnated polymer. It was found that polyaniline is uniformly dispersed within the wood structure by light microscopy and FT-IR imaging. A weight percent gain in the range of 3-12 wt % was obtained with a preferential formation in the wood structure and cell wall, rather than in the lumen. The modified wood was found to be less hydrophilic with the addition of phosphate doped polyaniline as observed by equilibrium water swelling studies. While wood itself is insulating, the modified veneers had conductivities of 1 × 10(-4) to 1 × 10(-9) S cm(-1), demonstrating the ability to tune the conductivity and allowing for materials with a wide range of applications, from anti-static to charge-dispersing materials. Furthermore, the modified veneers had lower total and peak heat releases, as determined by cone calorimetry, because of the char properties of the ICP. This is of interest if these materials are to be used in building and furniture applications where flame retardance is of importance. © 2012 American Chemical Society

  5. Nanoreinforced biocompatible hydrogels from wood hemicelluloses and cellulose whiskers

    Science.gov (United States)

    Muzaffer Ahmet Karaaslan; Mandla A. Tshabalala; Daniel J. Yelle; Gisela Buschle-Diller

    2011-01-01

    Nanoreinforced hydrogels with a unique network structure were prepared from wood cellulose whiskers coated with chemically modified wood hemicelluloses. The hemicelluloses were modified with 2-hydroxyethylmethacrylate prior to adsorption onto the cellulose whiskers in aqueous medium. Synthesis of the hydrogels was accomplished by in situ radical polymerization of the...

  6. Laboratory tests on fungal resistance of wood filled polyethylene composites

    Science.gov (United States)

    Craig M. Clemons; Rebecca E. Ibach

    2002-01-01

    A standard method for determining the durability of structural wood was modified for testing the fungal resistance of composites made from high density polyethylene filled with 50% wood flour. Moisture content, mechanical properties, and weight loss were measured over 12 weeks exposure to brown-and white-rot fungi. Mechanical properties were decreased, but irreversible...

  7. A comparative study of wood highway sound barriers

    Science.gov (United States)

    Stefan Grgurevich; Thomas Boothby; Harvey Manbeck; Courtney Burroughs; Stephen Cegelka; Craig Bernecker; Michael A. Ritter

    2002-01-01

    Prototype designs for wood highway sound barriers meeting the multiple criteria of structural integrity, acoustic effectiveness, durability, and potential for public acceptance have been developed. Existing installations of wood sound barriers were reviewed and measurements conducted in the field to estimate acoustic insertion losses. A complete matrix of design...

  8. Adhesives with wood materials : bond formation and performance

    Science.gov (United States)

    Charles R. Frihart; Christopher G. Hunt

    2010-01-01

    Adhesive bonding of wood plays an increasing role in the forest products industry and is a key factor for efficiently utilizing our timber resource. The main use of adhesives is in the manufacture of building materials, including plywood, oriented strandboard, particleboard, fiberboard, structural composite lumber, doors, windows and frames, and factory-laminated wood...

  9. Residential Mechanical Precooling

    Energy Technology Data Exchange (ETDEWEB)

    German, Alea [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation (ARBI); Hoeschele, Marc [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation (ARBI)

    2014-12-01

    Residential air conditioning (AC) represents a challenging load for many electric utilities with poor load factors. Mechanical precooling improves the load factor by shifting cooling operation from on-peak to off-peak hours. This provides benefits to utilities and the electricity grid, as well as to occupants who can take advantage of time-of-use (TOU) electricity rates. Performance benefits stem from reduced compressor cycling, and shifting condensing unit operation to earlier periods of the day when outdoor temperatures are more favorable to operational efficiency. Finding solutions that save energy and reduce demand on the electricity grid is an important national objective and supports key Building America goals. The Alliance for Residential Building Innovation team evaluated mechanical AC precooling strategies in homes throughout the United States. EnergyPlus modeling was used to evaluate two homes with different performance characteristics in seven climates. Results are applicable to new construction homes and most existing homes built in the last 10 years, as well as fairly efficient retrofitted homes. A successful off-peak AC strategy offers the potential for increased efficiency and improved occupant comfort, and promotes a more reliable and robust electricity grid. Demand response capabilities and further integration with photovoltaic TOU generation patterns provide additional opportunities to flatten loads and optimize grid impacts.

  10. Regional prices in the Swedish wood-fuel market

    International Nuclear Information System (INIS)

    Hillring, Bengt

    1999-01-01

    This paper analyses, through a statistical survey, the regional distribution of prices on the commercial wood-fuel market for district heating plants and the pellets market for single family houses. The existing market watch of the national Swedish wood-fuel market has been developed for both refined and unrefined wood-fuels. The last five years the trend for wood-fuel prices on the district heating market has been stable, with a slight increase in the price of refined wood-fuels. However, on the young and fast-growing household market for pellets, prices have increased 12% during the last three years. The distribution of prices for northern, middle and southern Sweden indicates differences within 5% between the regions. The limited price difference between Swedish regions are a product of a large domestic supply and an increasing trade among regions in Europe, putting pressure on prices. Regional differences, mirrored as transportation distances and local production costs are key factors that could explain this regional price variation. However, the development of a commercial market with less regulation tends to level out prices. Consumers on the household market purchase small quantities and do not have the same possibility as district heating companies to take advantage of the oversupply opportunity and thus face a faster price development. The weaker market position of the consumers also tends to give homogeneous prices between regions of the residential sector. (Author)

  11. Residential energy demand in Brazil

    International Nuclear Information System (INIS)

    Arouca, M.; Gomes, F.M.; Rosa, L.P.

    1981-01-01

    The energy demand in Brazilian residential sector is studied, discussing the methodology for analyzing this demand from some ideas suggested, for developing an adequate method to brazilian characteristics. The residential energy consumption of several fuels in Brazil is also presented, including a comparative evaluation with the United States and France. (author)

  12. 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.

  13. Morphology, composition, and mixing state of primary particles from combustion sources ? crop residue, wood, and solid waste

    OpenAIRE

    Liu, Lei; Kong, Shaofei; Zhang, Yinxiao; Wang, Yuanyuan; Xu, Liang; Yan, Qin; Lingaswamy, A. P.; Shi, Zongbo; Lv, Senlin; Niu, Hongya; Shao, Longyi; Hu, Min; Zhang, Daizhou; Chen, Jianmin; Zhang, Xiaoye

    2017-01-01

    Morphology, composition, and mixing state of individual particles emitted from crop residue, wood, and solid waste combustion in a residential stove were analyzed using transmission electron microscopy (TEM). Our study showed that particles from crop residue and apple wood combustion were mainly organic matter (OM) in smoldering phase, whereas soot-OM internally mixed with K in flaming phase. Wild grass combustion in flaming phase released some Cl-rich-OM/soot particles and cardboard combusti...

  14. An economic model of international wood supply, forest stock and forest area change

    Science.gov (United States)

    James A. Turner; Joseph Buongiorno; Shushuai Zhu

    2006-01-01

    Wood supply, the link between roundwood removals and forest resources, is an important component of forest sector models. This paper develops a model of international wood supply within the structure of the spatial equilibrium Global Forest Products Model. The wood supply model determines, for each country, the annual forest harvest, the annual change of forest stock...

  15. Thinning and riparian buffer configuration effects on down wood abundance in headwater streams in coniferous forests

    Science.gov (United States)

    Adrian Ares; Deanna H. Olson; Klaus J. Puettmann

    2013-01-01

    Down wood is associated with the function, structure, and diversity of riparian systems. Considerable knowledge has been generated regarding down wood stocks and dynamics in temperate forests, but there are few studies on effects of silvicultural practices and riparian buffer design on down wood, particularly in headwater streams. We analyzed interactive eff ects of...

  16. Wood and Other Materials Used to Construct Nonresidential Buildings in the United States 2011 Executive Summary

    Science.gov (United States)

    David B. McKeever

    2013-01-01

    The construction of low-rise nonresidential buildings is an important market for lumber, engineered wood products, and structural and nonstructural wood panels in the United States. This report examines low-rise nonresidential buildings of six or fewer stories. Those with more than six stories are normally severely restricted by building codes from being wood framed....

  17. Wood and Other Materials Used to Construct Nonresidential Buildings in the United States 2011

    Science.gov (United States)

    Craig Adair; David B. McKeever; Chris Gaston; Margaret. Stewart

    2013-01-01

    The construction of low-rise nonresidential buildings is an important market for lumber, engineered wood products, and structural and nonstructural wood panels in the United States. This report examines low-rise nonresidential buildings of six or fewer stories. Those with more than six stories are normally severely restricted by building codes from being wood framed....

  18. Estimating U.S. residential demand for fuelwood in the presence of selectivity

    Science.gov (United States)

    Daly, Ryan Michael

    Residential energy consumers have options for home heating. With many applications, appliances, and fuel types, fuelwood used for heating faces stiff competition in modern society from other fuels. This study estimates demand for domestic fuelwood. It also examines whether evidence of bias exists from residential homes choosing to use fuelwood. The use of OLS as an estimator will yield biased results if such selectivity exists. Selectivity is addressed with a Heckman (1979) two-step procedure; bias in fuelwood demand estimation using OLS is reduced. Non-wood energy prices and income are major determinants of fuelwood demand. Geographical regions and urbanization confirm results from prior studies.

  19. Wood and Wood-Based Materials as Sensors—A Review of the Piezoelectric Effect in Wood

    Science.gov (United States)

    Robert J. Ross; Jiangming Kan; Xiping Wang; Julie Blankenburg; Janet I. Stockhausen; Roy F. Pellerin

    2012-01-01

    A variety of techniques have been investigated for use in assessing the physical and mechanical properties of wood products and structures. Ultrasound, transverse vibration, and stress-wave based methods are all techniques that have shown promise for many nondestructive evaluation applications. These techniques and others rely on the use of measurement systems to...

  20. 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)

  1. 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

  2. Panethnicity, Ethnic Diversity and Residential Segregation

    Science.gov (United States)

    Kim, Ann H.; White, Michael J.

    2013-01-01

    We consider the theoretical and empirical implications of the structural basis of panethnicity and of the layering of ethnic boundaries in residential patterns while simultaneously evaluating the ‘panethnic hypothesis’, that is, the extent to which homogeneity within panethnic categories can be assumed. Our results do show a panethnic effect – greater residential proximity is evident within panethnic boundaries than between, net of ethnic group size and metropolitan area, but this association clearly depends on immigration. While findings generally show a lower degree of social distance between panethnic subgroups, particularly for blacks, whites and Latinos and less for Asians, ethno-national groups continue to maintain some degree of distinctiveness within a racialized context. PMID:20503650

  3. 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)

  4. Belongingness--The Critical Variable in the Residential Treatment of Alcoholism.

    Science.gov (United States)

    Machell, David F.

    Many alcohol treatment programs have stressed a sense of belongingness as a means for successful treatment of alcoholics in a residential setting. An examination of the effectiveness of this strategy in highly structured and less structured programs involved 200 chronic, recidivistic male adult alcoholics in a residential program. Subjects were…

  5. Residential Energy Performance Metrics

    Directory of Open Access Journals (Sweden)

    Christopher Wright

    2010-06-01

    Full Text Available Techniques for residential energy monitoring are an emerging field that is currently drawing significant attention. This paper is a description of the current efforts to monitor and compare the performance of three solar powered homes built at Missouri University of Science and Technology. The homes are outfitted with an array of sensors and a data logger system to measure and record electricity production, system energy use, internal home temperature and humidity, hot water production, and exterior ambient conditions the houses are experiencing. Data is being collected to measure the performance of the houses, compare to energy modeling programs, design and develop cost effective sensor systems for energy monitoring, and produce a cost effective home control system.

  6. Duration of load effects of solid wood

    DEFF Research Database (Denmark)

    Svensson, Staffan

    Test methods for studying the effect of long-term loading on the load carrying capacity of structural wood are discussed. The impact of sampling procedures on test results is investigated and is exemplified. It is concluded from this investigation that the sampling method has a significant impact...

  7. Anisotropy of Wood in the Microwave Region

    Science.gov (United States)

    Ziherl, Sasa; Bajc, Jurij; Urankar, Bernarda; Cepic, Mojca

    2010-01-01

    Wood is transparent for microwaves and due to its anisotropic structure has anisotropic dielectric properties. A laboratory experiment that allows for the qualitative demonstration and quantitative measurements of linear dichroism and birefringence in the microwave region is presented. As the proposed experiments are based on the anisotropy (of…

  8. Photostabilization of wood flour filled HDPE composites

    Science.gov (United States)

    Nicole M. Stark; Laurent M. Matuana

    2002-01-01

    Wood/plastic composites are increasingly examined for non-structural building applications. As outdoor applications become more widespread, durability becomes an issue. Ultraviolet exposure can lead to photodegradation, resulting in a change in appearance and/or mechanical properties. Photodegradation can be slowed through the addition of photostabilizers. This study...

  9. Wood versus metal in airplane construction

    Science.gov (United States)

    Seehase, H

    1923-01-01

    The aim of this article is to present, in broad outline, a scientific method for solving the problem, "Wood or Metal." It will be shown that structural methods have by no means reached their final perfection. The strength of the different materials is discussed as well as different construction methods.

  10. 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.

  11. 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.

  12. 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.

  13. Wood-Based Nanotechnologies toward Sustainability.

    Science.gov (United States)

    Jiang, Feng; Li, Tian; Li, Yiju; Zhang, Ying; Gong, Amy; Dai, Jiaqi; Hitz, Emily; Luo, Wei; Hu, Liangbing

    2018-01-01

    With over 30% global land coverage, the forest is one of nature's most generous gifts to human beings, providing shelters and materials for all living beings. Apart from being sustainable, renewable, and biodegradable, wood and its derivative materials are also extremely fascinating from a materials aspect, with numerous advantages including porous and hierarchical structure, excellent mechanical performance, and versatile chemistry. Here, strategies for designing novel wood-based materials via advanced nanotechnologies are summarized, including both the controllable bottom-up assembly from the highly crystalline nanocellulose building block and the more efficient top-down approaches directly from wood. Beyond material design, recent advances regarding the sustainable applications of these novel wood-based materials are also presented, focusing on areas that are traditionally dominated by man-made nonrenewable materials such as plastic, glass, and metals, as well as more advanced applications in the areas of energy storage, wastewater treatment and solar-steam-assisted desalination. With all recent progress pertaining to materials' design and sustainable applications presented, a vision for the future engineering of wood-based materials to promote continuous and healthy progress toward true sustainability is outlined. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Optimization of wood plastic composite decks

    Science.gov (United States)

    Ravivarman, S.; Venkatesh, G. S.; Karmarkar, A.; Shivkumar N., D.; Abhilash R., M.

    2018-04-01

    Wood Plastic Composite (WPC) is a new class of natural fibre based composite material that contains plastic matrix reinforced with wood fibres or wood flour. In the present work, Wood Plastic Composite was prepared with 70-wt% of wood flour reinforced in polypropylene matrix. Mechanical characterization of the composite was done by carrying out laboratory tests such as tensile test and flexural test as per the American Society for Testing and Materials (ASTM) standards. Computer Aided Design (CAD) model of the laboratory test specimen (tensile test) was created and explicit finite element analysis was carried out on the finite element model in non-linear Explicit FE code LS - DYNA. The piecewise linear plasticity (MAT 24) material model was identified as a suitable model in LS-DYNA material library, describing the material behavior of the developed composite. The composite structures for decking application in construction industry were then optimized for cross sectional area and distance between two successive supports (span length) by carrying out various numerical experiments in LS-DYNA. The optimized WPC deck (Elliptical channel-2 E10) has 45% reduced weight than the baseline model (solid cross-section) considered in this study with the load carrying capacity meeting acceptance criterion (allowable deflection & stress) for outdoor decking application.

  15. Dynamic management of integrated residential energy systems

    Science.gov (United States)

    Muratori, Matteo

    dissertation presents a bottom-up highly resolved model of a generic residential energy eco-system in the United States. The model is able to capture the entire energy footprint of an individual household, to include all appliances, space conditioning systems, in-home charging of plug-in electric vehicles, and any other energy needs, viewing residential and transportation energy needs as an integrated continuum. The residential energy eco-system model is based on a novel bottom-up approach that quantifies consumer energy use behavior. The incorporation of stochastic consumer behaviors allows capturing the electricity consumption of each residential specific end-use, providing an accurate estimation of the actual amount of available controllable resources, and for a better understanding of the potential of residential demand response programs. A dynamic energy management framework is then proposed to manage electricity consumption inside each residential energy eco-system. Objective of the dynamic energy management framework is to optimize the scheduling of all the controllable appliances and in-home charging of plug-in electric vehicles to minimize cost. Such an automated energy management framework is used to simulate residential demand response programs, and evaluate their impact on the electric power infrastructure. For instance, time-varying electricity pricing might lead to synchronization of the individual residential demands, creating pronounced rebound peaks in the aggregate demand that are higher and steeper than the original demand peaks that the time-varying electricity pricing structure intended to eliminate. The modeling tools developed in this study can serve as a virtual laboratory for investigating fundamental economic and policy-related questions regarding the interplay of individual consumers with energy use. The models developed allow for evaluating the impact of different energy policies, technology adoption, and electricity price structures on the total

  16. 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)

  17. 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)

  18. How to quantify conduits in wood?

    Science.gov (United States)

    Scholz, Alexander; Klepsch, Matthias; Karimi, Zohreh; Jansen, Steven

    2013-01-01

    Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.

  19. 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.

  20. 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.

  1. 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...

  2. Impregnating Systems for Producing Wood-Plastic Composite Materials and Resinified Woods by Radiochemical Means

    International Nuclear Information System (INIS)

    Laizier, J.; Laroche, R.; Marchand, J.

    1969-01-01

    The effect of the nature of the components in the impregnation mixture on the characteristics of wood-plastic combinations has been studied in the case of beech by applying a wide variety of compositions. In particular, the effect of water (in the impregnator, and in the form of moisture in the wood) on the characteristics of the products obtained has been determined. It has been shown that, in place of the conventional method for preparing resinified woods (using a ternary monomer-solvent-water mixture), it is possible to use a method involving comonomers, which obviate the need to dry the wood after treatment. The evaluation of the results obtained is based on the value of the impregnation rate and on the modifications in microscopic structure; these emphasize the differences between the types of filler and enable comparisons to be drawn with the dimensional stabilities observed. Measurements of variations in dimensions and the recurrence of moisture have made it possible to establish a classification based on the types of monomer used and the operating conditions. It is shown that a whole range of products is obtained, the properties of which differ widely and are comparatively easily adaptable to the purpose specified. These properties illustrate clearly the differences and characteristics of resinified woods as opposed to conventional wood-plastic materials. (author) [fr

  3. Inside the guts of wood-eating catfishes: can they digest wood?

    Science.gov (United States)

    German, Donovan P

    2009-11-01

    To better understand the structure and function of the gastrointestinal (GI) tracts of wood-eating catfishes, the gross morphology, length, and microvilli surface area (MVSA) of the intestines of wild-caught Panaque nocturnus, P. cf. nigrolineatus "Marañon", and Hypostomus pyrineusi were measured, and contrasted against these same metrics of a closely related detritivore, Pterygoplichthys disjunctivus. All four species had anatomically unspecialized intestines with no kinks, valves, or ceca of any kind. The wood-eating catfishes had body size-corrected intestinal lengths that were 35% shorter than the detritivore. The MVSA of all four species decreased distally in the intestine, indicating that nutrient absorption preferentially takes place in the proximal and mid-intestine, consistent with digestive enzyme activity and luminal carbohydrate profiles for these same species. Wild-caught Pt. disjunctivus, and P. nigrolineatus obtained via the aquarium trade, poorly digested wood cellulose (<33% digestibility) in laboratory feeding trials, lost weight when consuming wood, and passed stained wood through their digestive tracts in less than 4 h. Furthermore, no selective retention of small particles was observed in either species in any region of the gut. Collectively, these results corroborate digestive enzyme activity profiles and gastrointestinal fermentation levels in the fishes' GI tracts, suggesting that the wood-eating catfishes are not true xylivores such as beavers and termites, but rather, are detritivores like so many other fishes from the family Loricariidae.

  4. 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.

  5. Emission factors from residential combustion appliances burning Portuguese biomass fuels.

    Science.gov (United States)

    Fernandes, A P; Alves, C A; Gonçalves, C; Tarelho, L; Pio, C; Schimdl, C; Bauer, H

    2011-11-01

    Smoke from residential wood burning has been identified as a major contributor to air pollution, motivating detailed emission measurements under controlled conditions. A series of experiments were performed to compare the emission levels from two types of wood-stoves to those of fireplaces. Eight types of biomass were burned in the laboratory: wood from seven species of trees grown in the Portuguese forest (Pinus pinaster, Eucalyptus globulus, Quercus suber, Acacia longifolia, Quercus faginea, Olea europaea and Quercus ilex rotundifolia) and briquettes produced from forest biomass waste. Average emission factors were in the ranges 27.5-99.2 g CO kg(-1), 552-1660 g CO(2) kg(-1), 0.66-1.34 g NO kg(-1), and 0.82-4.94 g hydrocarbons kg(-1) of biomass burned (dry basis). Average particle emission factors varied between 1.12 and 20.06 g kg(-1) biomass burned (dry basis), with higher burn rates producing significantly less particle mass per kg wood burned than the low burn rates. Particle mass emission factors from wood-stoves were lower than those from the fireplace. The average emission factors for organic and elemental carbon were in the intervals 0.24-10.1 and 0.18-0.68 g kg(-1) biomass burned (dry basis), respectively. The elemental carbon content of particles emitted from the energy-efficient "chimney type" logwood stove was substantially higher than in the conventional cast iron stove and fireplace, whereas the opposite was observed for the organic carbon fraction. Pinus pinaster, the only softwood species among all, was the biofuel with the lowest emissions of particles, CO, NO and hydrocarbons.

  6. 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 ...

  7. How to decrease the hydrophilicity of wood flour to process efficient composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Pouzet, M.; Gautier, D.; Charlet, K. [Institut Pascal, UMR 6602 UBP/CNRS/IFMA, BP 265, Aubière 63175 (France); Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, Clermont-Ferrand 63000 (France); CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, Aubière 63177 (France); Dubois, M., E-mail: Marc.DUBOIS@univ-bpclermont.fr [Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, Clermont-Ferrand 63000 (France); CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, Aubière 63177 (France); Béakou, A. [Institut Pascal, UMR 6602 UBP/CNRS/IFMA, BP 265, Aubière 63175 (France)

    2015-10-30

    Graphical abstract: Evolution of the contact angle of a water drop on sample (θ{sub c}) according to the fluorinated material. - Highlights: • Fluorination was applied to wood flour. • Covalent attachment of fluorine atoms onto wood surface decreases its hydrophilicity. • Fluorinated wood flour was added into composites with polyester. • Fluorination enhances the interface between wood flour and polymer matrix. - Abstract: Dynamic fluorination and static fluorination were applied to wood flour to decrease its hydrophilic character, aiming at processing wood-polymer composites with good properties. Fourier-Transform infrared spectra and {sup 19}F solid state NMR (Nuclear Magnetic Resonance) results proved the successful covalent bonding of fluorine atoms onto the wood's chemical structure. It revealed that static fluorination brings about a less damaged and less hydrophilic fluorinated wood than with dynamic fluorination. Composites manufactured from this fluorinated wood presented a hydrophobic character directly related to the hydrophicity of these wood reinforcements. A composite made with fluorinated wood and polyester exhibited a higher hydrophobicity than the neat polyester and than the composite made with non-treated wood. Moreover, the further fluorination of a composite made of fluorinated wood led to a contact angle comparable to that of some metals (steel, gold) due to the etching of the composite surface during fluorination.

  8. The effect of some wood preservatives on the thermal degradation of Scots pine

    International Nuclear Information System (INIS)

    Tomak, Eylem D.; Baysal, Ergun; Peker, Huseyin

    2012-01-01

    Highlights: ► Scots pine samples were impregnated with 10 commercial wood preservatives. ► Thermal degradation of wood was evaluated by TG, DTG and DTA. ► The thermal behavior of treated wood differed from that of untreated wood. ► Boron containing wood preservatives yielded more charcoal than other preservatives. ► Boric oxide and metal compounds in the formulations may affect char weight. - Abstract: Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effectiveness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups.

  9. The effect of some wood preservatives on the thermal degradation of Scots pine

    Energy Technology Data Exchange (ETDEWEB)

    Tomak, Eylem D., E-mail: eylemdizman@yahoo.com [Karadeniz Technical University, Faculty of Forestry, Forest Industrial Engineering Department, 61080 Trabzon (Turkey); Baysal, Ergun, E-mail: bergun@mu.edu.tr [Mugla University, Faculty of Technology, Department of Wood Science and Technology, Kotekli, 48000 Mugla (Turkey); Peker, Huseyin, E-mail: peker100@hotmail.com [Artvin Coruh University, Faculty of Forestry, Forest Industrial Engineering Department, 06100 Artvin (Turkey)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer Scots pine samples were impregnated with 10 commercial wood preservatives. Black-Right-Pointing-Pointer Thermal degradation of wood was evaluated by TG, DTG and DTA. Black-Right-Pointing-Pointer The thermal behavior of treated wood differed from that of untreated wood. Black-Right-Pointing-Pointer Boron containing wood preservatives yielded more charcoal than other preservatives. Black-Right-Pointing-Pointer Boric oxide and metal compounds in the formulations may affect char weight. - Abstract: Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effectiveness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups.

  10. Wood anatomy of Holmskioldia sanguinea Retz. and its adaptive and ecological significance

    Directory of Open Access Journals (Sweden)

    Manju Sahney

    2017-04-01

    Full Text Available Wood anatomy of Holmskioldia sanguinea Retz. has been done to study the structural variations in stem and root wood and to correlate them with growth habit and ecology of the plant. Vessels are wider and more abundant while rays (uni- to triserate are taller in stem wood than in root wood, which possesses broad multiseriate rays. Simple perforation plate, sparse vasicentric paratracheal parenchyma and perforated ray cells are the features common in both stem and root woods, while helical thickenings have been recorded only in the stem wood. Lower value of vulnerability, presence of wider vessels with simple perforation plate, and presence of helical thickening are indicators of wood xeromorphy in Holmskioldia sanguinea. Features like wider vessels and extensive height of rays in stem wood are in consonance with the climbing nature of the stem axis.

  11. 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

  12. 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

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  14. 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.

  15. Water sorption in wood and modified wood at high values of relative humidity

    DEFF Research Database (Denmark)

    Engelund, Emil Tang; Thygesen, Lisbeth Garbrecht; Hoffmeyer, Preben

    2010-01-01

    A theoretical study of the amount of moisture held in wood as capillary condensed water in the relative humidity (RH) range of 90–99.9% is carried out. The study is based on idealized geometries of the softwood structure related to micrographs. It is confined to structural elements such as bordered......, and different degrees of pit aspiration are assigned to earlywood and latewood. We suggest based on the results that capillary condensation makes only a very small contribution to the equilibrium moisture content. At 99.9% RH the contribution amounts to less than 0.0035 kg water per kg dry wood. This is in line...

  16. Method for improving separation of carbohydrates from wood pulping and wood or biomass hydrolysis liquors

    Science.gov (United States)

    Griffith, William Louis; Compere, Alicia Lucille; Leitten, Jr., Carl Frederick

    2010-04-20

    A method for separating carbohydrates from pulping liquors includes the steps of providing a wood pulping or wood or biomass hydrolysis pulping liquor having lignin therein, and mixing the liquor with an acid or a gas which forms an acid upon contact with water to initiate precipitation of carbohydrate to begin formation of a precipitate. During precipitation, at least one long chain carboxylated carbohydrate and at least one cationic polymer, such as a polyamine or polyimine are added, wherein the precipitate aggregates into larger precipitate structures. Carbohydrate gel precipitates are then selectively removed from the larger precipitate structures. The method process yields both a carbohydrate precipitate and a high purity lignin.

  17. 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.

  18. 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)

  19. 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...

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. ENERGY STAR Certified Residential Dishwashers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 6.0 ENERGY STAR Program Requirements for Residential Dishwashers that are effective as of...

  5. ENERGY STAR Certified Residential Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Residential Refrigerators and Freezers that are...

  6. ENERGY STAR Certified Residential Refrigerators

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Residential Refrigerators and Freezers that are...

  7. 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....

  8. Evaluating the Effectiveness of a Commercial Portable Air Purifier in Homes with Wood Burning Stoves: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Julie F. Hart

    2011-01-01

    Full Text Available Wood burning for residential heating is prevalent in the Rocky Mountain regions of the United States. Studies have shown that wood stoves can be a significant source of PM2.5 within homes. In this study, the effectiveness of an electrostatic filter portable air purifier was evaluated (1 in a home where a wood stove was the sole heat source and (2 in a home where a wood stove was used as a supplemental heat source. Particle count concentrations in six particle sizes and particle mass concentrations in two particle sizes were measured for ten 12-hour purifier on and ten purifier off trials in each home. Particle count concentrations were reduced by 61–85 percent. Similar reductions were observed in particle mass concentrations. These findings, although limited to one season, suggest that a portable air purifier may effectively reduce indoor particulate matter concentrations associated with wood combustion during home heating.

  9. Wood Export and Deposition Dynamics in Mountain Watersheds

    Science.gov (United States)

    Senter, Anne Elizabeth

    using decision tree analyses. Digital imagery collected via kite-blimp was mosaicked into a geographic information system and all resolvable wood pieces greater then 2.5 cm in one dimension were delineated and categorized into piece count density classes. Visual imagery was also key in identifying two river corridor terrains: bedrock outcrops and cobble-boulder-vegetation patches. A conceptual model framed an investigation into how topographic variability and structural elements might influence observed wood deposition dynamics. Forage ratio test results that quantified wood piece utilization versus interval availability revealed that high-density wood deposition patterns were most significantly co-located with five discrete bedrock outcrops that dominated small portions of the river corridor in high flow conditions. Topographic variations and cobble-boulder-vegetation patches were found to be subordinate factors in wood deposition patterns. Bedrock outcrops with specific structural components were the primary depositional environments that acted as floodplain extents for coarse wood deposition, with mechanisms such as topographic steering, eddying, trapping, stranding, backwater effects, and lateral roughness features inferred to be responsible for observed wood deposition patterns.

  10. The Value of Green Infrastructure on Vacant and Residential Land in Roanoke, Virginia

    Directory of Open Access Journals (Sweden)

    Gunwoo Kim

    2016-03-01

    Full Text Available Using the City of Roanoke, Virginia as a study site, this paper quantifies the forest structure, ecosystem services and values of vacant and residential land. Single family residential land had more trees (1,683,000 than vacant land (210,000 due largely to the differences in land area (32.44 km2 of vacant land vs. 57.94 km2 residential. While the percentage of tree coverage was almost identical across land uses (30.6% in vacant to 32.3% in residential, the number of trees per ha is greater on residential land (290.3 than on vacant land (63.4. The average healthy leaf surface area on individual trees growing on vacant land was greater than that of individual trees on residential land. The fact that trees in vacant land were found to provide more ecosystem services per tree than residential trees was attributed to this leaf area difference. Trees on vacant land are growing in more natural conditions and there are more large trees per ha. Assessing the forest structure and ecosystem services of Roanoke’s vacant and residential land provides a picture of the current extent and condition of the vacant and residential land. Understanding these characteristics provides the information needed for improved management and utilization of urban vacant land and estimating green infrastructure value.

  11. Effects of wood smoke particles from wood-burning stoves on the respiratory health of atopic humans

    Directory of Open Access Journals (Sweden)

    Riddervold Ingunn

    2012-04-01

    Full Text Available Abstract Background There is growing evidence that particulate air pollution derived from wood stoves causes acute inflammation in the respiratory system, increases the incidence of asthma and other allergic diseases, and increases respiratory morbidity and mortality. The objective of this study was to evaluate acute respiratory effects from short-term wood smoke exposure in humans. Twenty non-smoking atopic volunteers with normal lung function and without bronchial responsiveness were monitored during three different experimental exposure sessions, aiming at particle concentrations of about 200 μg/m3, 400 μg/m3, and clean air as control exposure. A balanced cross-over design was used and participants were randomly allocated to exposure orders. Particles were generated in a wood-burning facility and added to a full-scale climate chamber where the participants were exposed for 3 hours under controlled environmental conditions. Health effects were evaluated in relation to: peak expiratory flow (PEF, forced expiratory volume in the first second (FEV1, and forced vital capacity (FVC. Furthermore, the effects were assessed in relation to changes in nasal patency and from markers of airway inflammation: fractional exhaled nitric oxide (FENO, exhaled breath condensate (EBC and nasal lavage (NAL samples were collected before, and at various intervals after exposure. Results No statistically significant effect of wood smoke exposure was found for lung function, for FENO, for NAL or for the nasal patency. Limited signs of airway inflammation were found in EBC. Conclusion In conclusion, short term exposure with wood smoke at a concentration normally found in a residential area with a high density of burning wood stoves causes only mild inflammatory response.

  12. 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.

  13. Influence of India’s transformation on residential energy demand

    International Nuclear Information System (INIS)

    Bhattacharyya, Subhes C.

    2015-01-01

    Highlights: • The middle income group emerges as the dominant segment by 2030. • Commercial residential energy demand increases 3–4 folds compared to 2010. • Electricity and LPG demand grows above 6% per year in the reference scenario. • India faces the potential of displacing the domination of biomass by 2030. - Abstract: India’s recent macro-economic and structural changes are transforming the economy and bringing significant changes to energy demand behaviour. Life-style and consumption behaviour are evolving rapidly due to accelerated economic growth in recent times. The population structure is changing, thereby offering the country with the potential to reap the population dividend. The country is also urbanising rapidly, and the fast-growing middle class segment of the population is fuelling consumerism by mimicking international life-styles. These changes are likely to have significant implications for energy demand in the future, particularly in the residential sector. Using the end-use approach of demand analysis, this paper analyses how residential energy demand is likely to evolve as a consequence of India’s transformation and finds that by 2030, India’s commercial energy demand in the residential sector can quadruple in the high scenario compared to the demand in 2010. Demand for modern fuels like electricity and liquefied petroleum gas is likely to grow at a faster rate. However, there is a window of opportunity to better manage the evolution of residential demand in India through energy efficiency improvement

  14. 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)

  15. 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.)

  16. 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.)

  17. 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.

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

    OpenAIRE

    Umemura, Kenji; Ueda, Tomohide; Kawai, Shuichi

    2012-01-01

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

  19. Wood-Polymer composites obtained by gamma irradiation

    International Nuclear Information System (INIS)

    Gago, J.; Lopez, A.; Rodriguez, J.; Santiago, J.; Acevedo, M.

    2007-01-01

    In this work we impregnate three Peruvian woods (Calycophy spruceanum Be, Aniba amazonica Meiz and Hura crepitans L) with styrene-polyester resin and methyl methacrylate. The polymerization of the system was promoted by gamma radiation and the experimental optimal condition was obtained with styrene-polyester 1:1 and 15 kGy. The obtained composites show reduced water absorption and better mechanical properties compared to the original wood. The structure of the wood-polymer composites was studied by light microscopy. Water absorption and hardness were also obtained

  20. Wood-Polymer composites obtained by gamma irradiation

    Science.gov (United States)

    Gago, J.; López, A.; Santiago, J.; Acevedo, M.; Rodríguez, J.

    2007-10-01

    In this work we impregnate three Peruvian woods (Calycophy spruceanum Be, Aniba amazonica Meiz and Hura crepitans L) with styrene-polyester resin and methyl methacrylate. The polymerization of the system was promoted by gamma radiation and the experimental optimal condition was obtained with styrene-polyester 1:1 and 15 kGy. The obtained composites show reduced water absorption and better mechanical properties compared to the original wood. The structure of the wood-polymer composites was studied by light microscopy. Water absorption and hardness were also obtained.

  1. 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)

  2. Design of an Advanced Wood Composite Rotor and Development of Wood Composite Blade Technology

    Science.gov (United States)

    Stroebel, Thomas; Dechow, Curtis; Zuteck, Michael

    1984-01-01

    In support of a program to advance wood composite wind turbine blade technology, a design was completed for a prototype, 90-foot diameter, two-bladed, one-piece rotor, with all wood/epoxy composite structure. The rotor was sized for compatibility with a generator having a maximum power rating of 4000 kilowatts. Innovative features of the rotor include: a teetering hub to minimize the effects of gust loads, untwisted blades to promote rotor power control through stall, joining of blades to the hub structure via an adhesive bonded structural joint, and a blade structural design which was simplified relative to earlier efforts. The prototype rotor was designed to allow flexibility for configuring the rotor upwind or downwind of the tower, for evaluating various types of teeter dampers and/or elastomeric stops, and with variable delta-three angle settings of the teeter shaft axis. The prototype rotor was also designed with provisions for installing pressure tap and angle of attack instrumentation in one blade. A production version rotor cost analysis was conducted. Included in the program were efforts directed at developing advanced load take-off stud designs for subsequent evaluation testing by NASA, development of aerodynamic tip brake concepts, exploratory testing of a wood/epoxy/graphite concept, and compression testing of wood/epoxy laminate, with scarf-jointed plies.

  3. MINERGIE modules: heat pump - heat pump/solar - wood - wood/solar; Minergie-Module Waermepumpe - Waermepumpe/Solar - Holz - Holz/Solar

    Energy Technology Data Exchange (ETDEWEB)

    Gallati, J. [Seecon GmbH, Lucerne (Switzerland); Portmann, M. [Buero Markus Portmann, Kriens (Switzerland); Zurfluh, B. [Zurfluh Lottenbach, Lucerne (Switzerland)

    2005-07-01

    This research report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined the feasibility of setting up 'MINERGIE' low-energy-consumption module standards for the production of heat in small residential buildings. The aims of the standards and the basic idea behind the MINERGIE-modules are discussed. The concepts of the modules for heat pumps and wood-fired heating systems and their combination with solar installations are examined, as are their areas of application. The requirements placed on the modules are listed. System concepts, including simple schematics for typical installations, are presented for wood-log, wood-chippings and pellets-fired systems as well as for ground-loop and air-water heat pump systems as well as their solar-aided counterparts. The results of cost-benefit analyses are presented and questions regarding system guarantee and liability are examined.

  4. Wood constructions. Energy eficient, sustainable, practically proven; Holzbau Konstruktionen. Energieeffizient, nachhaltig, praxisgerecht

    Energy Technology Data Exchange (ETDEWEB)

    Lueckmann, Rudolf

    2012-07-01

    The book 'Wood constructions' provides standardized and practically proven designs, all necessary information on building physics, fire protection and additional specialized knowledge for energy efficient renovations and construction details in wood construction. The main topics of this book are: Fundamentals, timber-frame structures, wood preservation, thermal insulation, sound insulation, fire protection, energy-efficient timber buildings, timber construction systems, rehabilitation of timber structures, relevant regulations and standards.

  5. Reactivity and burnout of wood fuels

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Ora, M.

    2011-07-01

    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 in the boiler and thereby the overall operation and efficiency of the plant. Chapter 1 consists of an introduction to thermal conversion of biomass fuels as well as a description of a Danish power plant where a measuring campaign was carried out as part of this project. Chapter 2 is a brief literature review 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 on the relation between pyrolysis of wood in boiler-like conditions and wood char properties is presented. Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyser. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperature varied in the range 673-1673 K for slow pyrolysis and 1073-1573 K for fast pyrolysis. The chars were oxidised in a thermogravimetric analyser and the mass loss data were used to determine char oxidation reactivity. Char yield from fast pyrolysis (104-105 K/s) was as low as 1-6% on a dry ash free basis, whereas it was about 15-17% for slow pyrolysis (10-20 K/min); char yield decreased as

  6. 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

  7. 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.)

  8. Measuring urban tree loss dynamics across residential landscapes.

    Science.gov (United States)

    Ossola, Alessandro; Hopton, Matthew E

    2018-01-15

    The spatial arrangement of urban vegetation depends on urban morphology and socio-economic settings. Urban vegetation changes over time because of human management. Urban trees are removed due to hazard prevention or aesthetic preferences. Previous research attributed tree loss to decreases in canopy cover. However, this provides little information about location and structural characteristics of trees lost, as well as environmental and social factors affecting tree loss dynamics. This is particularly relevant in residential landscapes where access to residential parcels for field surveys is limited. We tested whether multi-temporal airborne LiDAR and multi-spectral imagery collected at a 5-year interval can be used to investigate urban tree loss dynamics across residential landscapes in Denver, CO and Milwaukee, WI, covering 400,705 residential parcels in 444 census tracts. Position and stem height of trees lost were extracted from canopy height models calculated as the difference between final (year 5) and initial (year 0) vegetation height derived from LiDAR. Multivariate regression models were used to predict number and height of tree stems lost in residential parcels in each census tract based on urban morphological and socio-economic variables. A total of 28,427 stems were lost from residential parcels in Denver and Milwaukee over 5years. Overall, 7% of residential parcels lost one stem, averaging 90.87 stems per km 2 . Average stem height was 10.16m, though trees lost in Denver were taller compared to Milwaukee. The number of stems lost was higher in neighborhoods with higher canopy cover and developed before the 1970s. However, socio-economic characteristics had little effect on tree loss dynamics. The study provides a simple method for measuring urban tree loss dynamics within and across entire cities, and represents a further step toward high resolution assessments of the three-dimensional change of urban vegetation at large spatial scales. Published by

  9. The structure and properties of ZrN-Ni-Co-coatings on the edges steel knives of wood-cutting tools

    International Nuclear Information System (INIS)

    Chaevskij, V.V.; Grishkevich, A.A.; Zhilinskij, V.V.; Kuleshov, A.K.

    2015-01-01

    Modes were selected and formed electroplated Ni-Co-coatings, ion-plasma Zr N-coatings as well as combined Zr N-Ni-Co-coating on the edges steel (type R6M5) knives of wood-cutting milling tools. Formed electroplated Ni-Co-layers are not mixed with the steel substrate and the Zr N-coating. Microhardness of combined Zr N-Ni-Co-coatings is to 1,2-1,5 times more than microhardness of steel base and bare steel. When cutting laminated chipboard by steel knives of milling tool with a Ni-Co- and Zr N-Ni-Co-coatings under laboratory conditions, abrasive surface wear type of edges knives is observed. Calculating bulk wear of edges knives with Zr N-Ni-Co-coatings showed reduction of more than 3 times value in comparison with knives with Ni-Co-coatings. Pilot testing of tool modified with combined Zr N-Ni-Co-coatings at OJSC 'Minskdrev' when cutting pine confirmed relevance of the tests carried out, as well as showed an increase in durability period of cutters to 30% compared with bare tool. (authors)

  10. THERMAL DEGRADATION AND MORPHOLOGICAL ASPECTS OF FOUR WOOD SPECIES USED IN LUMBER INDUSTRY

    Directory of Open Access Journals (Sweden)

    Matheus Poletto

    Full Text Available ABSTRACT The aim of this work was characterize four wood waste samples from lumber industry in order to obtain previous information about structure and properties of wood before use it as a biofuel or as reinforcement in composite formulations. The influence of wood components on the thermal degradation stability of different wood species has been investigated using thermogravimetry, differential scanning calorimetry and scanning electron microscopy. Four wood species, Eucalyptus grandis (EUG, Pinus elliottii (PIE, Dipteryx odorata (DIP and Mezilaurus itauba (ITA, were used in this study. The results showed that higher extractives contents may form a thin film on the wood fiber surface which can accelerate the degradation process and reduce the wood thermal stability

  11. Radial variation of wood physical properties in Pinus patula growing in Mozambique

    Directory of Open Access Journals (Sweden)

    Claudio Gumane Francisco Juizo

    2015-09-01

    Full Text Available  This study aimed to evaluate wood physical properties of Pinus patula, aged 38, from a forest stand located in Machipanda, central region of Mozambique. Determination of physical properties, such as basic specific gravity, shrinkage, and moisture content of wood in the pith-bark followed the recommendations of the Panamerican Standard - COPANT. Results showed statistically significant differences at significance level of 5%, in the radial direction for the shrinkage coefficient in the pith-bark. Radial and tangential shrinkage values were 6.06 and 8.80% in juvenile wood and 6.18 and 8.65% in adult wood, respectively, with anisotropy coefficient of 1.43 for juvenile wood and 2.44 for adult wood. Pinus patula growing in Inhamacari forest shows stable wood at age 38. It can be used for structural purposes and for manufacture of joinery and furniture.

  12. ELASTIC CHARACTERIZATION OF Eucalyptus citriodora WOOD

    Directory of Open Access Journals (Sweden)

    Adriano Wagner Ballarin

    2003-01-01

    Full Text Available This paper contributed to the elastic characterization of Eucalyptus citriodora grown inBrazil, considering an orthotropic model and evaluating its most important elastic constants.Considering this as a reference work to establish basic elastic ratios — several important elasticconstants of Brazilian woods were not determined yet - the experimental set-up utilized one tree of 65years old from plantations of “Horto Florestal Navarro de Andrade”, at Rio Claro-SP, Brazil. All theexperimental procedures attended NBR 7190/97 – Brazilian Code for wooden structures –withconventional tension and compression tests. Results showed statistical identity between compressionand tension modulus of elasticity. The relation observed between longitudinal and radial modulus ofelasticity was 10 (EL/ER ≈ 10 and same relation, considering shear modulus (modulus of rigidity was20 (EL/GLR ≈ 20. These results, associated with Poisson’s ratios herein determined, allow theoreticalmodeling of wood mechanical behavior in structures.

  13. Radon reduction in wood foundation system

    International Nuclear Information System (INIS)

    Clark, R.J.

    1990-01-01

    Radon, an issue of growing concern to the building industry. Silently, invisibly, it invades existing structures as it will future foundation structures. This paper addresses the nature and causes of radon, and cost-effective prevention and retrofit techniques used for wood foundation systems. Radon also can enter homes with foundations that use the under-floor as an air distribution system. These building practices will be shown; even materials used in construction may release radon, for example, this may be a problem in a house that has a solar heating system in which its heat is stored in large beds of stone. Stone is most often used in wood foundation construction. The common radon entry points will be looked at, and the latest prevention techniques will be illustrated, such as natural and forced ventilation, sealing major radon sources and entry routes, and sub-slab and sump crock ventilations

  14. Quantitative features of Cedrela odorata L. wood (Meliaceae)

    OpenAIRE

    Luchi, Agnes E.

    2011-01-01

    Cedrela odorata L. (Meliaceae) occurs in the Atlantic forest, Amazon rain forest, riparian forest of the country, and wetlands, which demand species adapted to their water conditions. Studies in ecological wood anatomy demonstrated that weather factors' variations have direct influence on the wood anatomical structure and that the fragmentation of the natural habitats is a direct cause of the edge effect which alters the abiotic aspects of the location, interfering consequently in its vegetat...

  15. 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)

  16. 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.)

  17. Thermal load histories for North American roof assembles using various cladding materials including wood-thermoplastic composite shingles

    Science.gov (United States)

    J. E. Winandy

    2006-01-01

    Since 1991, thermal load histories for various roof cladding types have been monitored in outdoor attic structures that simulate classic North American light-framed construction. In this paper, the 2005 thermal loads for wood-based composite roof sheathing, wood rafters, and attics under wood-plastic composite shingles are compared to common North American roof...

  18. Modelling long term energy consumption of French residential sector - improving behavioral realism and simulating ambitious scenarios

    International Nuclear Information System (INIS)

    Allibe, Benoit

    2012-01-01

    This thesis aims to integrate components of an economic model of the behaviors of households in a technological model of French residential sector energy consumption dynamics and to analyze the consequences of this integration on the results of long-term residential energy consumption simulations (2030-2050). The results of this work highlight significant differences between the actual household space heating energy consumptions and those estimated by engineering models. These differences are largely due to the elasticity of thermal comfort demand to thermal comfort price. Our improved model makes it possible to conjointly integrate the concepts of price elasticity and rebound effect (the increase in energy service level following an improvement in energy performance of the equipment providing the service) in a daily behavior model. Regarding space heating consumption, the consequences of this behavioral adaptation - combined with some technical defects - are a significant reduction of the technical and behavioral energy saving potentials (while effective daily use of energy is generally lower than predicted by engineering models) at a national level. This implies that mid and long-term national energy policy targets (a 38% drop in primary energy consumption by 2020 and a reduction in greenhouse gas emissions by a factor of 4 by 2050 compared to the 1990 level) will be harder to reach than previously expected for the residential sector. These results also imply that a strong reduction in carbon emissions cannot be achieved solely through the diffusion of efficient technologies and energy conservation behavior but also requires to significantly lower the average carbon content of residential space heating energy through the generalized use of wood energy. The second issue addressed in this thesis is the influence of the resolution of a techno-economic model (i.e. its ability to represent the various values that a variable can have within the modeled system) on its

  19. 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.

  20. 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...

  1. 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 ...

  2. 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.

  3. Understanding Residential Polarization in a Globalizing City

    Directory of Open Access Journals (Sweden)

    Ibrahim Rotimi Aliu

    2013-12-01

    Full Text Available This study examines the spatial polarization that characterizes the dwellings in the African leading megacity of Lagos. Data were collected through an extensive housing survey carried out on 1,485 household residences in 56 wards within 12 administrative units in Lagos megacity. The spatial dimension of residential density in the city generates three unique residential patterns which are low residential density (LRD, medium residential density (MRD, and high residential density (HRD areas. Descriptive and multivariate inferential statistics were used to render explanations for the spatial variations in the residential quality variables in the study area. Findings indicated that a clear difference exists in the residential quality within the three residential density areas of Lagos. High correlations exist among the residential quality indicators and housing type. The principal component analysis shows that residential polarizations that occur in the LRD, MRD, and HRD are based on the location, dwelling facility, interior and exterior quality, neighborhood integrity, social bond, barrier to entry, and security. The practical implications of residential polarizations along the residential density areas are explicitly expressed.

  4. 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

  5. Technical Problems of Residential Construction

    Science.gov (United States)

    Nowogońska, Beata; Cibis, Jerzy

    2017-10-01

    Beauty, utility, durability - these are the features of good architecture and should also be the distinguishing qualities of every residential building. But do beauty and utility remain along with the passing of time? Performance characteristics are an indicator of both, the technical as well as aesthetic state of buildings. Aesthetic needs are in disagreement with the merciless aging process. The beauty of a city is formed not only by the original forms of new residential buildings, but also by existing tenement housing; thus preserving their aesthetics becomes a necessity. Time is continuously passing and along with it, aging intensifies. The aging process is a natural phenomenon for every material. The life expectancy of building materials is also limited. Along with the passing of time, the technical state of residential buildings continuously deteriorates. With the passing of time, the aesthetic values and preferences of users of flats change and the usability of the building decreases. The permanence of buildings, including residential buildings, is shaped not only by the forces of nature but also by activities of humans. A long lifespan is ensured by carrying out ongoing, systematic renovation-repair works. It is thanks to them that buildings derived from past centuries are still being used, and their market attractiveness is not decreasing.

  6. Main challenges of residential areas

    Directory of Open Access Journals (Sweden)

    Oana Luca

    2017-06-01

    Full Text Available The present article is a position paper aiming to initiate a professional debate related to the aspects related to the urban dysfunctions leading to the wear of the residential areas. The paper proposes a definition of the wear process, identify the main causes leading to its occurrence and propose a number of solutions to neutralise the dysfunctions. The three wearing phases of residential areas components are emphasized, exploring their lifecycle. In order to perform the study of urban wear, the status of the residential areas components can be established and monitored, and also the variables of the function that can mathematically model the specific wear process may be considered. The paper is considered a first step for the model adjustment, to be tested and validated in the following steps. Based on the mathematical method and model, there can be created, in a potential future research, the possibility of determining the precarity degree for residential areas/neighbourhoods and cities, by minimising the subjective component of the analyses preceding the decision for renovation or regeneration.

  7. Residential solar-heating system

    Science.gov (United States)

    1978-01-01

    Complete residential solar-heating and hot-water system, when installed in highly-insulated energy-saver home, can supply large percentage of total energy demand for space heating and domestic hot water. System which uses water-heating energy storage can be scaled to meet requirements of building in which it is installed.

  8. Convergence of Residential Gateway Technology

    NARCIS (Netherlands)

    Hartog, F.T.H. den; Balm, M.; Jong, C.M. de; Kwaaitaal, J.J.B.

    2004-01-01

    A new OSI-based model is described that can be used for the classification of residential gateways. It is applied to analyze current gateway solutions and draw evolutionary paths for the medium to long term. From this it is concluded that particularly set-top boxes and broadband modems, as opposed

  9. Convergence of residential gateway technology

    NARCIS (Netherlands)

    Hartog, den F.T.H.; Balm, M.; Jong, de C.M.; Kwaaitaal, J.J.B.

    2004-01-01

    A new OSI-based model is described that can be used for the classification of residential gateways. It is applied to analyze current gateway solutions and draw evolutionary paths for the medium to long term. From this it is concluded that particularly set-top boxes and broadband modems, as opposed

  10. Trends of Sustainable Residential Architecture

    OpenAIRE

    Narvydas, A

    2014-01-01

    The article is based on Master’s research conducted during Scottish Housing Expo 2010. The aim of the research was to determine the prevailing trends in sustainable residential architecture. Each trend can be described by features detected during visual and technical observation of project data. Based on that architects may predict possible problems related to a specific trend.

  11. Zones 30 : urban residential areas.

    NARCIS (Netherlands)

    2006-01-01

    Sustainable Safety uses a road categorization in which through traffic is concentrated on motorways and other main roads. In residential areas, which have a living, shopping, or work function, through traffic is discouraged by setting a speed limit of 30 km/h, and by speed reducing measures such as

  12. Biocide leaching from CBA treated wood — A mechanistic interpretation

    International Nuclear Information System (INIS)

    Lupsea, Maria; Mathies, Helena; Schoknecht, Ute; Tiruta-Barna, Ligia; Schiopu, Nicoleta

    2013-01-01

    Treated wood is frequently used for construction. However, there is a need to ensure that biocides used for the treatment are not a threat for people or environment. The paper focused on Pinus sylvestris treated with copper–boron–azole (CBA), containing tebuconazole as organic biocide and monoethanolamine (Mea). This study investigates chemical mechanisms of fixation and mobilisation involved in the leaching process of the used inorganic and organic biocides in CBA. A pH dependent leaching test was performed, followed by a set of complementary analysis methods in order to identify and quantify the species released from wood. The main findings of this study are: -Organic compounds are released from untreated and treated wood; the quantity of released total organic carbon, carboxylic and phenolic functions increasing with the pH. -Nitrogen containing compounds, i.e. mainly Mea and its reaction products with extractives, are released in important quantities from CBA treated wood, especially at low pH. -The release of copper is the result of competitive reactions: fixation via complexation reactions and complexation with extractives in the liquid phase. The specific pH dependency of Cu leaching is explained by the competition of ligands for protonation and complexation. -Tebuconazole is released to a lesser extent relative to its initial content. Its fixation on solid wood structure seems to be influenced by pH, suggesting interactions with -OH groups on wood. Boron release appears to be pH independent and very high. This confirms its weak fixation on wood and also no or weak interaction with the extractives. - Highlights: ► A pH dependent leaching mechanism for CBA treated wood is described. ► The fixation and mobilisation of inorganic and organic biocides was investigated. ► Extractives' quantity and nature depend on pH. ► Competition of ligands for protonation and complexation explains Cu behaviour. ► Tebuconazole seems to interact with -OH groups on

  13. 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.

  14. High Performance Residential Housing Units at U.S. Coast Guard Base Kodiak: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Romero, R.; Hickey, J.

    2013-10-01

    The United States Coast Guard (USCG) constructs residential housing throughout the country using a basic template that must meet the minimum Leadership in Energy and Environmental Design (LEED) Silver criteria or better for the units. In Kodiak, Alaska, USCG is procuring between 24 and 100 residential multi-family housing units. Priorities for the Kodiak project were to reduce overall energyconsumption by at least 20% over existing units, improve envelope construction, and evaluate space heating options. USCG is challenged with maintaining similar existing units that have complicated residential diesel boilers. Additionally, fuel and material costs are high in Kodiak. While USCG has worked to optimize the performance of the housing units with principles of improved buildingenvelope, the engineers realize there are still opportunities for improvement, especially within the heating, ventilation, and air conditioning (HVAC) system and different envelope measures. USCG staff also desires to balance higher upfront project costs for significantly reduced life-cycle costs of the residential units that have an expected lifetime of 50 or more years. To answer thesequestions, this analysis used the residential modeling tool BEoptE+ to examine potential energy- saving opportunities for the climate. The results suggest criteria for achieving optimized housing performance at the lowest cost. USCG will integrate the criteria into their procurement process. To achieve greater than 50% energy savings, USCG will need to specify full 2x 6 wood stud R-21 insulationwith two 2 inches of exterior foam, R-38 ceiling insulation or even wall insulation in the crawl space, and R-49 fiberglass batts in a the vented attic. The air barrier should be improved to ensure a tight envelope with minimal infiltration to the goal of 2.0 ACH50. With the implementation of an air source heat pump for space heating requirements, the combination of HVAC and envelope savings inthe residential unit can save

  15. Construction of hydrophobic wood surfaces by room temperature deposition of rutile (TiO2) nanostructures

    Science.gov (United States)

    Rongbo Zheng; Mandla A. Tshabalala; Qingyu Li; Hongyan Wang

    2015-01-01

    A convenient room temperature approach was developed for growing rutile TiO2 hierarchical structures on the wood surface by direct hydrolysis and crystallization of TiCl3 in saturated NaCl aqueous solution.The morphology and the crystal structure of TiO2 coated on the wood surface were characterized...

  16. A 3D multilevel model of damage and strength of wood: Analysis of microstructural effects

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2011-01-01

    A 3D hierarchical computational model of damage and strength of wood is developed. The model takes into account the four scale microstructures of wood, including the microfibril reinforced structure at nanoscale, multilayered cell walls at microscale, hexagon-shape-tube cellular structure...

  17. 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...

  18. 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

  19. 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...

  20. 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)