Electrodialytic remediation of CCA treated waste wood in pilot scale

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Christensen, Iben Vernegren; Ottosen, Lisbeth M.

2005-01-01

study the utility of the method Electrodialytic Remediation was demonstrated for handling of CCA treated waste wood in pilot scale. The electrodialytic remediation method, which uses a low level DC current as the cleaning agent, combines elektrokinetic movement of ions in the wood matrix with the princi......-ples of electrodialysis. It has previously been shown that it is possible to remove Cu, Cr and As from CCA treated wood using electrodialytic remediation in laboratory scale (Ribeiro et al., 2000; Kristensen et al., 2003), but until now, the method had not been studied in larger scale. The pilot scale plant used...... in this study was designed to contain up to 2 m3 wood chips. Six remediation experiments were carried out. In these experiments, the process was up-scaled stepwise by increasing the distance between the electrodes from initially 60 cm to fi-nally 150 cm. The remediation time was varied between 11 and 21 days...

CCA-treated wood disposed in landfills and life-cycle trade-offs with waste-to-energy and MSW landfill disposal.

Science.gov (United States)

Jambeck, Jenna; Weitz, Keith; Solo-Gabriele, Helena; Townsend, Timothy; Thorneloe, Susan

2007-01-01

Chromated copper arsenate (CCA)-treated wood is a preservative treated wood construction product that grew in use in the 1970s for both residential and industrial applications. Although some countries have banned the use of the product for some applications, others have not, and the product continues to enter the waste stream from construction, demolition and remodeling projects. CCA-treated wood as a solid waste is managed in various ways throughout the world. In the US, CCA-treated wood is disposed primarily within landfills; however some of the wood is combusted in waste-to-energy (WTE) facilities. In other countries, the predominant disposal option for wood, sometimes including CCA-treated wood, is combustion for the production of energy. This paper presents an estimate of the quantity of CCA-treated wood entering the disposal stream in the US, as well as an examination of the trade-offs between landfilling and WTE combustion of CCA-treated wood through a life-cycle assessment and decision support tool (MSW DST). Based upon production statistics, the estimated life span and the phaseout of CCA-treated wood, recent disposal projections estimate the peak US disposal rate to occur in 2008, at 9.7 million m(3). CCA-treated wood, when disposed with construction and demolition (C&D) debris and municipal solid waste (MSW), has been found to increase arsenic and chromium concentrations in leachate. For this reason, and because MSW landfills are lined, MSW landfills have been recommended as a preferred disposal option over unlined C&D debris landfills. Between landfilling and WTE for the same mass of CCA-treated wood, WTE is more expensive (nearly twice the cost), but when operated in accordance with US Environmental Protection Agency (US EPA) regulations, it produces energy and does not emit fossil carbon emissions. If the wood is managed via WTE, less landfill area is required, which could be an influential trade-off in some countries. Although metals are concentrated

Leaching of chromated copper arsenate (CCA)-treated wood in a simulated monofill and its potential impacts to landfill leachate

Energy Technology Data Exchange (ETDEWEB)

Jambeck, Jenna R. [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States); Townsend, Timothy [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States)]. E-mail: ttown@ufl.edu; Solo-Gabriele, Helena [Department of Civil, Architectural, and Environmental Engineering, University of Miami, Coral Gables, FL 33146-0630 (United States)

2006-07-31

The proper end-of-life management of chromated copper arsenate (CCA)-treated wood, which contains arsenic, copper, and chromium, is a concern to the solid waste management community. Landfills are often the final repository of this waste stream, and the impacts of CCA preservative metals on leachate quality are not well understood. Monofills are a type of landfill designed and operated to dispose a single waste type, such as ash, tires, mining waste, or wood. The feasibility of managing CCA-treated wood in monofills was examined using a simulated landfill (a leaching lysimeter) that contained a mix of new and weathered CCA-treated wood. The liquid to solid ratio (LS) reached in the experiment was 0.63:1. Arsenic, chromium, and copper leached from the lysimeter at average concentrations of 42 mg/L for arsenic, 9.4 mg/L for chromium, and 2.4 mg/L for copper. Complementary batch leaching studies using deionized water were performed on similar CCA-treated wood samples at LS of 5:1 and 10:1. When results from the lysimeter were compared to the batch test results, copper and chromium leachability appeared to be reduced in the lysimeter disposal environment. Of the three metals, arsenic leached to the greatest extent and was found to have the best correlation between the batch and the lysimeter experiments.

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.

New Approach to Remove Metals from Chromated Copper Arsenate (CCA)-Treated Wood

Science.gov (United States)

Todd F. Shupe; Chung Y. Hse; Hui Pan

2012-01-01

Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated using binary acid solutions consisting of acetic, oxalic, and phosphoric acids in a microwave reactor. Formation of an insoluble copper oxalate complex in the binary solution containing oxalic acid was the major factor for low copper removal. Furthermore, the...

Demonstration of the efficiency and robustness of an acid leaching process to remove metals from various CCA-treated wood samples.

Science.gov (United States)

Coudert, Lucie; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Janin, Amélie; Gastonguay, Louis

2014-01-01

In recent years, an efficient and economically attractive leaching process has been developed to remove metals from copper-based treated wood wastes. This study explored the applicability of this leaching process using chromated copper arsenate (CCA) treated wood samples with different initial metal loading and elapsed time between wood preservation treatment and remediation. The sulfuric acid leaching process resulted in the solubilization of more than 87% of the As, 70% of the Cr, and 76% of the Cu from CCA-chips and in the solubilization of more than 96% of the As, 78% of the Cr and 91% of the Cu from CCA-sawdust. The results showed that the performance of this leaching process might be influenced by the initial metal loading of the treated wood wastes and the elapsed time between preservation treatment and remediation. The effluents generated during the leaching steps were treated by precipitation-coagulation to satisfy the regulations for effluent discharge in municipal sewers. Precipitation using ferric chloride and sodium hydroxide was highly efficient, removing more than 99% of the As, Cr, and Cu. It appears that this leaching process can be successfully applied to remove metals from different CCA-treated wood samples and then from the effluents. Copyright © 2013 Elsevier Ltd. All rights reserved.

CCA retention and its effects on the bonding performance of decommissioned treated wood: a preliminary study

Science.gov (United States)

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

2009-01-01

Chromated copper arsenate (CCA) continues to be widely used as a wood preservative for industrial uses in the U.S. Disposal of treated wood is a potential long-term environmental liability. Current practices for disposing of decommissioned preservative-treated wood include landfilling and incineration, which are increasingly impractical due to environmental...

Electrodialytic remediation of CCA-treated waste wood in a 2 m3 pilot plant

DEFF Research Database (Denmark)

Christensen, Iben Vernegren; Pedersen, Anne Juul; Ottosen, Lisbeth M.

2006-01-01

Waste wood that has been treated with chromated-copper-arsenate (CCA) poses a potential environmental problem due to the content of copper, chromium and arsenic. A pilot plant for electrodialytic remediation of up to 2 m3 wood has been designed and tested and the results are presented here. Sever...

Landfill disposal of CCA-treated wood with construction and demolition (C&D) debris: arsenic, chromium, and copper concentrations in leachate.

Science.gov (United States)

Jambeck, Jenna R; Townsend, Timothy G; Solo-Gabriele, Helena M

2008-08-01

Although phased out of many residential uses in the United States, the disposal of CCA-treated wood remains a concern because significant quantities have yet to be taken out of service, and it is commonly disposed in landfills. Catastrophic events have also led to the concentrated disposal of CCA-treated wood, often in unlined landfills. The goal of this research was to simulate the complex chemical and biological activity of a construction and demolition (C&D) debris landfill containing a realistic quantity of CCA-treated wood (10% by mass), produce leachate, and then evaluate the arsenic, copper, and chromium concentrations in the leachate as an indication of what may occur in a landfill setting. Copper concentrations were not significantly elevated in the control or experimental simulated landfill setting (alpha = 0.05). However, the concentrations of arsenic and chromium were significantly higher in the experimental simulated landfill leachate compared to the control simulated landfill leachate (alpha = 0.05, p debris can impact leachate quality which, in turn could affect leachate management practices or aquifers below unlined landfills.

Effect of simulated rainfall and weathering on release of preservative elements from CCA treated wood

Science.gov (United States)

Stan Lebow; R. Sam Williams; Patricia Lebow

2003-01-01

The release of arsenic from wood pressure-treated with chromated copper arsenate (CCA) can be decreased by application of wood finishes, but little is known about the types of finishes that are best suited for this purpose. This study evaluated the effects of finish water repellent content and ultraviolet (UV) radiation on the release of arsenic, copper, and chromium...

Fixation effects on the release of copper, chromium and arsenic from CCA-C treated marine piles

Science.gov (United States)

Stan Lebow

1999-01-01

This study sought to determine the effect of fixation time and temperature on the release of copper, chromium and arsenic from treated marine piles immersed in seawater under "worst case" conditions. Sections of piles were CCA-C treated to a target retention of 2.5 lbs/ft3) (40 kg/m3) and then allowed to Condition at 36°F (2°C) for either 3, 7 or 20 days. As...

Utility poles not affected by CCA decision

Energy Technology Data Exchange (ETDEWEB)

De Venzio, H. [Arch Wood Protection Canada, Mississauga, ON (Canada)

2002-08-01

A voluntary decision by industry to move non-industrial use of treated lumber products away from pressure-treated wood containing chromated copper arsenate (CCA) preservative was announced by the Environmental Protection Agency on February 12, 2002. Although new alternative wood preservatives would be used, this decision does not affect utility poles, which will continue to be sold and installed. The author provides a brief historical outline concerning the creation of CCA in 1933 and its subsequent uses. CCA has many advantages, including clean surface of the poles, ground line treatment that is not required thus eliminating the requirement to rotate the poles during extended storage periods. Conductivity is low, as is corrosivity without affecting the bending characteristics of the wood. The injection of a refined hydrocarbon oil emulsion in the outer layer of the pole after the treatment with CCA is offered by some pole producers to facilitate gaff penetration. Sawing, drilling and nailing are also made easier. Water repellents can be added to the treating solution to improve climbability, slowing down the absorption and release of moisture. Warranties, extending for 50-year periods, are offered by some companies against wood-destroying organisms. The North American Wood Pole Coalition (NAWPC) was formed in 1998 to promote the use of wood poles, and publishes brochures and technical bulletins to that effect.

Improving the two-step remediation process for CCA-treated wood. Part I, Evaluating oxalic acid extraction

Science.gov (United States)

Carol Clausen

2004-01-01

In this study, three possible improvements to a remediation process for chromated-copper-arsenate (CCA) treated wood were evaluated. The process involves two steps: oxalic acid extraction of wood fiber followed by bacterial culture with Bacillus licheniformis CC01. The three potential improvements to the oxalic acid extraction step were (1) reusing oxalic acid for...

Oxalic acid as an assisting agent for the electrodialytic remediation of chromated copper arsenate treated timber waste

DEFF Research Database (Denmark)

Ribeiro, Alexandra B.; Mateus, Eduardo P.; Ottosen, Lisbeth M.

1999-01-01

The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber.......The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber....

Creosote treated timber in the Alaskan marine environment : Volume I.

Science.gov (United States)

2010-02-01

ADOT&PF is responsible for many structures that incorporate wood pilings and other timber in Alaska waters. Most are treated with preservative to inhibit marine borers : that will quickly destroy unprotected wood. Creosote is generally the most econo...

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).

A comparative study on Cu, Cr and As removal from CCA-treated wood waste by dialytic and electrodialytic processes

DEFF Research Database (Denmark)

Velizarova, Emiliya; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

2002-01-01

In this study, electrodialytic and dialytic techniques were used for Cu, Cr and As removal from 20-years out-of-service CCA-treated Pinus pinaster Ait. pole. The effect of applying direct current, as "cleaning agent", of up to 120mA was investigated. Focus was given to a parallel comparison...

Characterization and Low-Cost Remediation of Soils Contaminated by Timbers in Community Gardens.

Science.gov (United States)

Heiger-Bernays, W; Fraser, A; Burns, V; Diskin, K; Pierotti, D; Merchant-Borna, K; McClean, M; Brabander, D; Hynes, H P

2009-01-01

Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants. Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices. This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil.

Evaluation of commercial landscaping mulch for possible contamination from CCA.

Science.gov (United States)

Jacobi, Gary; Solo-Gabriele, Helena; Dubey, Brajesh; Townsend, Timothy; Shibata, Tomoyuki

2007-01-01

Wood treated with chromated copper arsenate (CCA) is found in construction and demolition (C&D) debris, and a common use for wood recycled from C&D debris is the production of mulch. Given the high metals concentrations in CCA-treated wood, a small fraction of CCA-treated wood can increase the metal concentrations in the mulch above regulatory thresholds. The objective of this study was to determine the extent of contamination of CCA-treated wood in consumer landscaping mulch and to determine whether visual methods or rapid X-ray fluorescence (XRF) technology can be used to identify suspect mulch. Samples were collected throughout the State of Florida (USA) and evaluated both visually and chemically. Visual analysis focused on documenting wood-chip size distribution, whether the samples were artificially colored, and whether they contained plywood chips which is an indication that the sample was, in part, made from recycled C&D wood. Chemical analysis included measurements of total recoverable metals, leachable metals as per the standardized synthetic precipitation leaching procedure (SPLP), and XRF analysis. Visual identification methods, such as colorant addition or presence of plywood, were found effective to preliminarily screen suspect mulch. XRF analysis was found to be effective for identifying mulch containing higher than 75 mg/kg arsenic. For mulch samples that were not colored and did not contain evidence of C&D wood, none exceeded leachable metal concentrations of 50 microg/L and only 3% exceeded 10 mg/kg for recoverable metals. The majority of the colored mulch made from recycled C&D wood contained from 1% to 5% CCA-treated wood (15% maximum fraction) resulting in leachable metals in excess of 50 microg/L and total recoverable metals in excess of 10 mg/kg. The maximum arsenic concentration measured in the mulch samples evaluated was 230 mg/kg, which was above the Florida residential direct exposure regulatory guideline of 2.1 mg/kg.

Effect of weathering on chromated copper arsenate (CCA) treated wood : leaching of metal salts and change in water repellency

Science.gov (United States)

R. Sam Williams; Stan Lebow; Patricia Lebow

2003-01-01

Wood pressure-treated with chromated copper arsenate (CCA) wood preservative is commonly used for outdoor construction. Oxides of arsenic, copper, and chromium are bound in the wood by a complex series of chemical reactions, but a small percentage of these compounds are gradually released by leaching and weathering. Recent studies suggest that the release of these...

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

Science.gov (United States)

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

2009-01-01

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

Effect of moisture content on strength of CCA-treated lumber

Science.gov (United States)

Jerrold E. Winandy

1995-01-01

Recent studies on the effects of chromated copper arsenate (CCA) treatment on lumber design properties have primarily evaluated the effects of such treatment at or near 12% moisture content and at failure times of 1 to 10 min. The influence of various moisture contents and faster loading rates is unknown. This report discusses the influence of moisture content and its...

Elemental analysis of ash residue from combustion of CCA treated wood waste before and after electrodialytic extraction

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Ottosen, Lisbeth M.

2006-01-01

Element distribution in a combined fly ash and bottom ash from combustion of copper chromate arsenate (CCA) treated wood waste was investigated by scanning electron microscopy (SEM/EDX) before and after electrodialytic extraction. The untreated ash contained various particles, including pieces...... of incompletely combusted wood rich in Cr and Ca, and irregular particles rich in Si, Al and K. Cr was also found incorporated in silica-based matrix particles. As was associated with Ca in porous (char) particles, indicating that Ca-arsenates had been formed during combustion. Cu was associated with Cr...... in the incompletely combusted wood pieces and was also found in almost pure form in a surface layer of some matrix particles – indicating surface condensation of volatile Cu species. In treated ash, Ca and As were no longer found together, indicating that Ca-arsenates had been dissolved due to the electrodialytic...

Identification and characterization of Burkholderia multivorans CCA53.

Science.gov (United States)

Akita, Hironaga; Kimura, Zen-Ichiro; Yusoff, Mohd Zulkhairi Mohd; Nakashima, Nobutaka; Hoshino, Tamotsu

2017-07-06

A lignin-degrading bacterium, Burkholderia sp. CCA53, was previously isolated from leaf soil. The purpose of this study was to determine phenotypic and biochemical features of Burkholderia sp. CCA53. Multilocus sequence typing (MLST) analysis based on fragments of the atpD, gltD, gyrB, lepA, recA and trpB gene sequences was performed to identify Burkholderia sp. CCA53. The MLST analysis revealed that Burkholderia sp. CCA53 was tightly clustered with B. multivorans ATCC BAA-247 T . The quinone and cellular fatty acid profiles, carbon source utilization, growth temperature and pH were consistent with the characteristics of B. multivorans species. Burkholderia sp. CCA53 was therefore identified as B. multivorans CCA53.

LWD–TCP complex activates the morning gene CCA1 in Arabidopsis

Science.gov (United States)

Wu, Jing-Fen; Tsai, Huang-Lung; Joanito, Ignasius; Wu, Yi-Chen; Chang, Chin-Wen; Li, Yi-Hang; Wang, Ying; Hong, Jong Chan; Chu, Jhih-Wei; Hsu, Chao-Ping; Wu, Shu-Hsing

2016-01-01

A double-negative feedback loop formed by the morning genes CIRCADIAN CLOCK ASSOCIATED1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) and the evening gene TIMING OF CAB EXPRESSION1 (TOC1) contributes to regulation of the circadian clock in Arabidopsis. A 24-h circadian cycle starts with the peak expression of CCA1 at dawn. Although CCA1 is targeted by multiple transcriptional repressors, including PSEUDO-RESPONSE REGULATOR9 (PRR9), PRR7, PRR5 and CCA1 HIKING EXPEDITION (CHE), activators of CCA1 remain elusive. Here we use mathematical modelling to infer a co-activator role for LIGHT-REGULATED WD1 (LWD1) in CCA1 expression. We show that the TEOSINTE BRANCHED 1-CYCLOIDEA-PCF20 (TCP20) and TCP22 proteins act as LWD-interacting transcriptional activators. The concomitant binding of LWD1 and TCP20/TCP22 to the TCP-binding site in the CCA1 promoter activates CCA1. Our study reveals activators of the morning gene CCA1 and provides an action mechanism that ensures elevated expression of CCA1 at dawn to sustain a robust clock. PMID:27734958

LWD-TCP complex activates the morning gene CCA1 in Arabidopsis.

Science.gov (United States)

Wu, Jing-Fen; Tsai, Huang-Lung; Joanito, Ignasius; Wu, Yi-Chen; Chang, Chin-Wen; Li, Yi-Hang; Wang, Ying; Hong, Jong Chan; Chu, Jhih-Wei; Hsu, Chao-Ping; Wu, Shu-Hsing

2016-10-13

A double-negative feedback loop formed by the morning genes CIRCADIAN CLOCK ASSOCIATED1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) and the evening gene TIMING OF CAB EXPRESSION1 (TOC1) contributes to regulation of the circadian clock in Arabidopsis. A 24-h circadian cycle starts with the peak expression of CCA1 at dawn. Although CCA1 is targeted by multiple transcriptional repressors, including PSEUDO-RESPONSE REGULATOR9 (PRR9), PRR7, PRR5 and CCA1 HIKING EXPEDITION (CHE), activators of CCA1 remain elusive. Here we use mathematical modelling to infer a co-activator role for LIGHT-REGULATED WD1 (LWD1) in CCA1 expression. We show that the TEOSINTE BRANCHED 1-CYCLOIDEA-PCF20 (TCP20) and TCP22 proteins act as LWD-interacting transcriptional activators. The concomitant binding of LWD1 and TCP20/TCP22 to the TCP-binding site in the CCA1 promoter activates CCA1. Our study reveals activators of the morning gene CCA1 and provides an action mechanism that ensures elevated expression of CCA1 at dawn to sustain a robust clock.

Evaluation of the wood CCA preservative treatment process of Eucalyptus (Eucaliptus ssp) by X-ray fluorescence technique

International Nuclear Information System (INIS)

Pereira Junior, Sergio Matias; Salvador, Vera Lucia Ribeiro; Sato, Ivone Mulako

2013-01-01

Brazil produces around 1,2 mi m 3 of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most used wood species are eucalyptus (Eucaliptus ssp)and pine (Pinus ssp). The most wood preservative products used in Brazil are CCA (Chromated Copper Arsenate) and CCB (Copper Chromium and Boron Salt). The analytical methods, such as Flame Atomic Absorption Spectrometry (FAAS) and Plasma Inductively Coupled Optical Emission Spectrometry (ICPOES) have been used for the evaluation of those treatment processes. In this work, the sapwood sample was obtained from eucalyptus trees (Eucaliptus ssp) obtained from Minas Gerais State, Brazil, cut plantation areas. Sawdust sapwood sample was grounded and submitted to different additions of CCA solutions (0.2, 0.7, 1.3, 2.3, 3.6, 6.3, 11.7and17.9 kg m -3 ). Power and pressed pellets sapwood samples, analyzed by EDXRFS, showed a good linear relation (r 2 >0.99) between the characteristic intensity fluorescent lines (CuΚα, CrΚαand AsΚΒ) and their concentration, also, showed adequate sensitivity (LQ -1 ) for Cu, Cr and As determination in treated woods. Cu, Cr and As were determined in powdered sawdust samples by FAA spectrometry, using the AWPA A11-93 standard method; the relation between the CCA retention and their concentration showed a lower linear relation than EDXRFS; the FAAS spreading result could be attributed to laboratorial CCA addition process. (author)

Hfq stimulates the activity of the CCA-adding enzyme

Directory of Open Access Journals (Sweden)

Betat Heike

2007-10-01

Full Text Available Abstract Background The bacterial Sm-like protein Hfq is known as an important regulator involved in many reactions of RNA metabolism. A prominent function of Hfq is the stimulation of RNA polyadenylation catalyzed by E. coli poly(A polymerase I (PAP. As a member of the nucleotidyltransferase superfamily, this enzyme shares a high sequence similarity with an other representative of this family, the tRNA nucleotidyltransferase that synthesizes the 3'-terminal sequence C-C-A to all tRNAs (CCA-adding enzyme. Therefore, it was assumed that Hfq might not only influence the poly(A polymerase in its specific activity, but also other, similar enzymes like the CCA-adding enzyme. Results Based on the close evolutionary relation of these two nucleotidyltransferases, it was tested whether Hfq is a specific modulator acting exclusively on PAP or whether it also influences the activity of the CCA-adding enzyme. The obtained data indicate that the reaction catalyzed by this enzyme is substantially accelerated in the presence of Hfq. Furthermore, Hfq binds specifically to tRNA transcripts, which seems to be the prerequisite for the observed effect on CCA-addition. Conclusion The increase of the CCA-addition in the presence of Hfq suggests that this protein acts as a stimulating factor not only for PAP, but also for the CCA-adding enzyme. In both cases, Hfq interacts with RNA substrates, while a direct binding to the corresponding enzymes was not demonstrated up to now (although experimental data indicate a possible interaction of PAP and Hfq. So far, the basic principle of these stimulatory effects is not clear yet. In case of the CCA-adding enzyme, however, the presented data indicate that the complex between Hfq and tRNA substrate might enhance the product release from the enzyme.

Evaluation of the wood CCA preservative treatment process of Eucalyptus (Eucaliptus ssp) by X-ray fluorescence technique

Energy Technology Data Exchange (ETDEWEB)

Pereira Junior, Sergio Matias, E-mail: matias@ipt.br [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Salvador, Vera Lucia Ribeiro; Sato, Ivone Mulako, E-mail: imsato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Brazil produces around 1,2 mi m{sup 3} of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most used wood species are eucalyptus (Eucaliptus ssp)and pine (Pinus ssp). The most wood preservative products used in Brazil are CCA (Chromated Copper Arsenate) and CCB (Copper Chromium and Boron Salt). The analytical methods, such as Flame Atomic Absorption Spectrometry (FAAS) and Plasma Inductively Coupled Optical Emission Spectrometry (ICPOES) have been used for the evaluation of those treatment processes. In this work, the sapwood sample was obtained from eucalyptus trees (Eucaliptus ssp) obtained from Minas Gerais State, Brazil, cut plantation areas. Sawdust sapwood sample was grounded and submitted to different additions of CCA solutions (0.2, 0.7, 1.3, 2.3, 3.6, 6.3, 11.7and17.9 kg m{sup -3}). Power and pressed pellets sapwood samples, analyzed by EDXRFS, showed a good linear relation (r{sup 2}>0.99) between the characteristic intensity fluorescent lines (CuΚα, CrΚαand AsΚΒ) and their concentration, also, showed adequate sensitivity (LQ < 5mgkg{sup -1}) for Cu, Cr and As determination in treated woods. Cu, Cr and As were determined in powdered sawdust samples by FAA spectrometry, using the AWPA A11-93 standard method; the relation between the CCA retention and their concentration showed a lower linear relation than EDXRFS; the FAAS spreading result could be attributed to laboratorial CCA addition process. (author)

Comparative study on liquefaction of creosote and chromated copper arsenate (CCA)-treated wood and untreated southern pine wood: effects of acid catalyst content, liquefaction time, temperature, and phenol to wood ratio

Science.gov (United States)

Hui Pan; Chung-Yun Hse; Todd F. Shupe

2009-01-01

Creosote- and chromated copper arsenate (CCA)-treated wood waste and untreated southern pine wood were liquefied with phenol and sulfuric acid. The effects of sulfuric acid content, liquefaction time, liquefaction temperature, and phenol to wood ratio on liquefaction rate (i.e., wood residue content) were investigated and analyzed by analysis of variance (...

Long-term soil accumulation of chromium, copper, and arsenic adjacent to preservative-treated wood.

Science.gov (United States)

S. Lebow; D. Foster; J. Evans

2004-01-01

Chromated copper arsenate (CCA) treated wood has been used extensively in outdoor applications. The Environmental Protection Agency (EPA) and CCA producers recently reached an agreement to limit future use of CCA for some types of applications. One area of concern is the long-term accumulation of leached CCA in soil adjacent to treated wood structures. Interpreting...

Laboratory investigation of fire protection coatings for creosote-treated timber railroad bridges

Science.gov (United States)

Carol A. Clausen; Robert H. White; James P. Wacker; Stan T. Lebow; Mark A. Dietenberger; Samuel L. Zelinka; Nicole M. Stark

2014-01-01

As the incidence of timber railroad bridge fires increases, so has the need to develop protective measures to reduce the risk from accidental ignitions primarily caused by hot metal objects. Of the six barrier treatments evaluated in the laboratory for their ability to protect timbers from fires sourced with ignition from hot metal objects only one intumescent coating...

Potential arsenic exposures in 25 species of zoo animals living in CCA-wood enclosures

International Nuclear Information System (INIS)

Gress, J.; Silva, E.B. da; Oliveira, L.M. de; Zhao, Di; Anderson, G.; Heard, D.; Stuchal, L.D.; Ma, L.Q.

2016-01-01

Animal enclosures are often constructed from wood treated with the pesticide chromated copper arsenate (CCA), which leaches arsenic (As) into adjacent soil during normal weathering. This study evaluated potential pathways of As exposure in 25 species of zoo animals living in CCA-wood enclosures. We analyzed As speciation in complete animal foods, dislodgeable As from CCA-wood, and As levels in enclosure soils, as well as As levels in biomarkers of 9 species of crocodilians (eggs), 4 species of birds (feathers), 1 primate species (hair), and 1 porcupine species (quills). Elevated soil As in samples from 17 enclosures was observed at 1.0–110 mg/kg, and enclosures housing threatened and endangered species had As levels higher than USEPA's risk-based Eco-SSL for birds and mammals of 43 and 46 mg/kg. Wipe samples of CCA-wood on which primates sit had dislodgeable As residues of 4.6–111 μg/100 cm 2 , typical of unsealed CCA-wood. Inorganic As doses from animal foods were estimated at 0.22–7.8 μg/kg bw/d. Some As levels in bird feathers and crocodilian eggs were higher than prior studies on wild species. However, hair from marmosets had 6.37 mg/kg As, 30-fold greater than the reference value, possibly due to their inability to methylate inorganic As. Our data suggested that elevated As in soils and dislodgeable As from CCA-wood could be important sources of As exposure for zoo animals. - Highlights: • Daily inorganic As dose from zoo animal foods was 0.22–7.8 μg/kg bw/day. • Total As concentrations in soils of zoo animal enclosures were 1.0–110 mg/kg. • Endangered zoo animals live in soils with As above USEPA Eco-SSLs for avian and mammal species. • Dislodgeable As on CCA-wood beams where primates sit was 4.6–111 μg/100 cm 2 . • Marmoset hair had 6.37 mg/kg As compared to a reference value of 0.21 mg/kg.

Potential arsenic exposures in 25 species of zoo animals living in CCA-wood enclosures

Energy Technology Data Exchange (ETDEWEB)

Gress, J. [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Silva, E.B. da; Oliveira, L.M. de [Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Zhao, Di [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Anderson, G. [Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Heard, D. [Department of Small Animal Clinical Sciences, University of Florida, Gainesville, FL 32610 (United States); Stuchal, L.D. [Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32611 (United States); Ma, L.Q., E-mail: lqma@ufl.edu [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States)

2016-05-01

Animal enclosures are often constructed from wood treated with the pesticide chromated copper arsenate (CCA), which leaches arsenic (As) into adjacent soil during normal weathering. This study evaluated potential pathways of As exposure in 25 species of zoo animals living in CCA-wood enclosures. We analyzed As speciation in complete animal foods, dislodgeable As from CCA-wood, and As levels in enclosure soils, as well as As levels in biomarkers of 9 species of crocodilians (eggs), 4 species of birds (feathers), 1 primate species (hair), and 1 porcupine species (quills). Elevated soil As in samples from 17 enclosures was observed at 1.0–110 mg/kg, and enclosures housing threatened and endangered species had As levels higher than USEPA's risk-based Eco-SSL for birds and mammals of 43 and 46 mg/kg. Wipe samples of CCA-wood on which primates sit had dislodgeable As residues of 4.6–111 μg/100 cm{sup 2}, typical of unsealed CCA-wood. Inorganic As doses from animal foods were estimated at 0.22–7.8 μg/kg bw/d. Some As levels in bird feathers and crocodilian eggs were higher than prior studies on wild species. However, hair from marmosets had 6.37 mg/kg As, 30-fold greater than the reference value, possibly due to their inability to methylate inorganic As. Our data suggested that elevated As in soils and dislodgeable As from CCA-wood could be important sources of As exposure for zoo animals. - Highlights: • Daily inorganic As dose from zoo animal foods was 0.22–7.8 μg/kg bw/day. • Total As concentrations in soils of zoo animal enclosures were 1.0–110 mg/kg. • Endangered zoo animals live in soils with As above USEPA Eco-SSLs for avian and mammal species. • Dislodgeable As on CCA-wood beams where primates sit was 4.6–111 μg/100 cm{sup 2}. • Marmoset hair had 6.37 mg/kg As compared to a reference value of 0.21 mg/kg.

Formation of metal agglomerates during carbonisation of chromated copper arsenate (CCA) treated wood waste: Comparison between a lab scale and an industrial plant

Energy Technology Data Exchange (ETDEWEB)

Helsen, Lieve [Katholieke Universiteit Leuven, Department of Mechanical Engineering, Division of Applied Mechanics and Energy Conversion, Celestijnenlaan 300A, B-3001 Leuven (Heverlee) (Belgium)]. E-mail: lieve.helsen@mech.kuleuven.be; Hacala, Amelie [Company Thermya, 1 rue Nicolas Appert, 33140 Villenave d' Ornon (France)]. E-mail: hacala@thermya.com

2006-10-11

This paper compares the results obtained by scanning electron microscopy coupled to X-ray analysis (SEM-EDXA) of the solid product after carbonisation of treated wood waste in a lab scale and in an industrial installation. These setups (lab scale and industrial) are characterized by different operating conditions of the carbonisation process. Moreover, the wood waste input to the processes differs significantly. From this study, it is clear that some similarities but also some differences exist between the lab scale study and the study with the industrial Chartherm plant. In both reactors, a metal (and mineral) agglomeration process takes place, even in the case of untreated wood. The agglomerates initially present in the wood input may serve as a seed for the metal agglomeration process during 'chartherisation'. The industrial setup leads to a broader range of agglomerates' size (0.1-50 {mu}m) and composition (all possible combinations of Cu, Cr, As and wood minerals). Some agglomerates contain the three metals but the major part is a combination of wood minerals and one or two of the three preservative metals, while all agglomerates analysed in the lab scale product contain the three metals. The separate influence of wood input characteristics and process conditions cannot be derived from these experiments, but the observations suggest that the higher the CCA retention in the wood input is, the easier is the metal agglomeration process during chartherisation of CCA treated wood waste. From the analyses performed in this study it seems that copper behaves differently in the sense that it agglomerates easily, but the resulting particles are small (<1 {mu}m)

Formation of metal agglomerates during carbonisation of chromated copper arsenate (CCA) treated wood waste: Comparison between a lab scale and an industrial plant

International Nuclear Information System (INIS)

Helsen, Lieve; Hacala, Amelie

2006-01-01

This paper compares the results obtained by scanning electron microscopy coupled to X-ray analysis (SEM-EDXA) of the solid product after carbonisation of treated wood waste in a lab scale and in an industrial installation. These setups (lab scale and industrial) are characterized by different operating conditions of the carbonisation process. Moreover, the wood waste input to the processes differs significantly. From this study, it is clear that some similarities but also some differences exist between the lab scale study and the study with the industrial Chartherm plant. In both reactors, a metal (and mineral) agglomeration process takes place, even in the case of untreated wood. The agglomerates initially present in the wood input may serve as a seed for the metal agglomeration process during 'chartherisation'. The industrial setup leads to a broader range of agglomerates' size (0.1-50 μm) and composition (all possible combinations of Cu, Cr, As and wood minerals). Some agglomerates contain the three metals but the major part is a combination of wood minerals and one or two of the three preservative metals, while all agglomerates analysed in the lab scale product contain the three metals. The separate influence of wood input characteristics and process conditions cannot be derived from these experiments, but the observations suggest that the higher the CCA retention in the wood input is, the easier is the metal agglomeration process during chartherisation of CCA treated wood waste. From the analyses performed in this study it seems that copper behaves differently in the sense that it agglomerates easily, but the resulting particles are small (<1 μm)

Extractive decontamination of heavy metals from CCA contaminated ...

African Journals Online (AJOL)

In this paper, the mobilization and extraction of As, Cr and Cu from chromated copper arsenate (CCA) contaminated soil obtained from a wood treatment factory site by four organic acids are presented and discussed. The CCA contaminated soil (pH = 5.91, carbon = 0.32, CEC = 47.84 meq/100 g) was found to contain 39.55 ...

Weight loss studies of fastener materials corrosion in contact with timbers treated with copper azole and alkaline copper quaternary compounds

Energy Technology Data Exchange (ETDEWEB)

Kear, Gareth [Building Research Association of New Zealand (BRANZ) Ltd., Science and Engineering Services, Private Bag 50 908, Porirua City 5240 (New Zealand)], E-mail: G.Kear@soton.ac.uk; Wu Haizhen; Jones, Mark S. [Building Research Association of New Zealand (BRANZ) Ltd., Science and Engineering Services, Private Bag 50 908, Porirua City 5240 (New Zealand)

2009-02-15

Corrosion rates of mild steel, AISI 316 stainless steel and hot-dipped galvanised steel in contact with preservative-treated Pinus radiata have been determined using four distinct accelerated (49 {+-} 1 deg. C) and non-accelerated (21 {+-} 2 deg. C) weight loss methodologies. The data were measured as a function of timber moisture content and copper concentration over periods of exposure ranging from 2 weeks to 14 months. The results show that the corrosion resistance of the stainless steel was not influenced by classification or magnitude of preservative loading. Corrosion rates of this material were multiple orders of magnitude lower than those of the mild and galvanised steels. In most instances, corrosion rates of hot-dipped galvanised layers in contact with alkaline copper quaternary-treated timbers were up to a factor of 10 times, or greater, than those measured for copper-chrome-arsenate treatments. A direct negative influence of copper ion concentration on the corrosion resistance of mild steel was also observed for each preservative type.

Resistance of treated rubber wood ( Hevea brasiliensis ) to termite ...

African Journals Online (AJOL)

Spent rubber trees from a 25 year old plantation were cut, sawn and treated with Copper Chromium Arsenate (CCA) and Cashew Nut Shell Liquid (CNSL). Two sets of wood samples were treated with CCA and CNSL respectively while the third set was not treated to serve as control. The three sets were exposed to termite ...

Caracterización de las cibercomunidades de aprendizaje (cCA

Directory of Open Access Journals (Sweden)

Iñaki Murua Anzola

2015-01-01

Full Text Available En este artículo se presentan los principales resultados de la investigación exploratoria llevada a cabo sobre las cibercomunidades de aprendizaje (cCA y la formación del profesorado aplicando , entre otros, el método Delphi; e l marco teórico y contextual de la misma se presentó en el número 43 de la revista RED. Los participantes de l panel de expertos han sido 31 encuestados online con el instrumento Delphi - cCA, y 19 respo nsables de comunidades que han contestado al cuestionario - cCA. Entre los principales resultados se destacan las condiciones para la creación y desarrollo de cCA, las herramientas y funcionalidades de las comunidades y las tipologías de participación ( perso nas implicadas, activas, pasivas y ausentes.

Durability of timber silencers at Wairakei geothermal steam field

Energy Technology Data Exchange (ETDEWEB)

Hedley, M E

1979-02-01

After early failures of reinforced concrete silencers and because of high costs of concrete-lined steel structures, preliminary tests were undertaken to assess the suitability of timber for silencer construction. Tests indicated that radiata pine treated with pentachlorophenol/oil or untreated red beech had most potential for timber silencer fabrication. One prototype silencer of each material was constructed and both were installed on operational bores in 1965. The red beech silencer had a service life of 4 years. The radiata pine silencer operated for 12/sup 1///sub 2/ years, although replacement had been recommended 1 year before this time expired. The performance of this silencer encouraged the general use of timber for silencer construction and further units were built. Procurement of satisfactory grades of timber has proved difficult and has limited silencer fabrication. Ways of improving timber supply, which require modification of silencer design, are discussed.

Effect of different extracting solutions on the electrodialytic remediation of CCA-treated wood waste Part I. - Behaviour of Cu and Cr

DEFF Research Database (Denmark)

Velizarova, E.; Ribeiro, A. B.; Mateus, E.

2004-01-01

Removal of Cu and Cr from chromated copper arsenate (CCA)-treated wood waste under batch electrodialytic conditions was studied. The effect of different types of extracting solutions, such as deionised water or aqueous solutions of NaCl, formic acid, oxalic acid, and EDTA, on the magnitude...... and direction of the fluxes of Cu- and Cr-containing species in the electrodialytic cell was investigated. Oxalic acid was found to have the best performance if simultaneous removal of the two elements is required (removal efficiencies of 80.5% for Cu and 87.4% for Cr, respectively). A mixture of oxalic acid...... and formic acid also led to similar removal efficiencies. In these experiments, the target elements were accumulated in both the anode and cathode compartments of the electrodialytic cell due to the formation of negatively charged complexes with the organic acids used besides the free cationic forms...

Standard plans for timber bridge superstructures

Science.gov (United States)

James P. Wacker; Matthew S. Smith

2001-01-01

These standardized bridge plans are for superstructures consisting of treated timber. Seven superstructure types are includes: five longitudinal and two transverse deck systems. Both HS520 and HS25 loadings are included, along with L/360 and L/500 deflection criteria.

Assessment of the environmental effects associated with wooden bridges preserved with creosote, pentachlorophenol, or chromated copper arsenate

Science.gov (United States)

Kenneth M. Brooks

Timber bridges provide an economical alternative to concrete and steel structures, particularly in rural areas with light to moderate vehicle traffic. Wooden components of these bridges are treated with chromated copper arsenate type C (CCA), pentachlorophenol, or creosote to prolong the life of the structure from a few years to many decades. This results in reduced...

A Novel Multilayer Correlation Maximization Model for Improving CCA-Based Frequency Recognition in SSVEP Brain-Computer Interface.

Science.gov (United States)

Jiao, Yong; Zhang, Yu; Wang, Yu; Wang, Bei; Jin, Jing; Wang, Xingyu

2018-05-01

Multiset canonical correlation analysis (MsetCCA) has been successfully applied to optimize the reference signals by extracting common features from multiple sets of electroencephalogram (EEG) for steady-state visual evoked potential (SSVEP) recognition in brain-computer interface application. To avoid extracting the possible noise components as common features, this study proposes a sophisticated extension of MsetCCA, called multilayer correlation maximization (MCM) model for further improving SSVEP recognition accuracy. MCM combines advantages of both CCA and MsetCCA by carrying out three layers of correlation maximization processes. The first layer is to extract the stimulus frequency-related information in using CCA between EEG samples and sine-cosine reference signals. The second layer is to learn reference signals by extracting the common features with MsetCCA. The third layer is to re-optimize the reference signals set in using CCA with sine-cosine reference signals again. Experimental study is implemented to validate effectiveness of the proposed MCM model in comparison with the standard CCA and MsetCCA algorithms. Superior performance of MCM demonstrates its promising potential for the development of an improved SSVEP-based brain-computer interface.

Forest owners' timber sales satisfaction

International Nuclear Information System (INIS)

Pammo, R.; Ripatti, P.

2003-01-01

The TTS Institute has carried out a study concerning forest owners' timber sales. The material was collected in 2002 via a mail inquiry that targeted forest owners who sold timber during the years 1997-1999 and 1999-2002. Three quarters of the forest owners sold timber to the same timber buying company during both periods of 1997-1999 and 1999-2002. The most important reasons for selling to the same buyer were that they purchased all timber assortments, reliability and good timber price. Mainly the same reasons also applied when changing the timber buying company. The most sensitive groups to changing timber buyer were 60-69 year old, entrepreneurs, men, and owners of forest holdings between 20-29 hectares, owners of inherited forests and joint forest ownerships. The forest owners assessed the timber buying company's operations and its staff on the basis of the last timber sale. The forest owners gave best values for the timber buyer's reliability, the purchase of all timber assortments and the timber buyers' reputation. The worst values were given for cross-cutting and response to complaints. No less than 95 percent of forest owners were prepared to recommend their timber trade partner to acquaintances, friends or other forest owners. Yet only half of the forest owners recognized that their last timber sale experience would not affect which company will be selected for the nest timber sale process

Evaluation of Strength Characteristics of Laterized Concrete with Corn Cob Ash (CCA) Blended Cement

Science.gov (United States)

Ikponmwosa, E. E.; Salau, M. A.; Kaigama, W. B.

2015-11-01

Agricultural wastes are dumped in landfills or left on land in which they constitute nuisance. This study presents the results of investigation of strength characteristics of reinforced laterized concrete beams with cement partially replaced with corn cob (agricultural wastes) ash (CCA). Laterized concrete specimen of 25% laterite and 75% sharp sand were made by blending cement with corn cob ash at 0 to 40% in steps of 10%. A concrete mix ratio of 1:2:4 was used to cast 54 cubes of 150×150×150mm size and 54 beams of dimension 750×150×150mm. The results show that the consistency and setting time of cement increased as the percentage replacement of cement with CCA increased while the workability and density of concrete decreased as the percentage of CCA increased. There was a decrease in compressive strength when laterite was introduced to the concrete from 25.04 to 22.96N/mm2 after 28 days and a continual reduction in strength when CCA was further added from 10% to 40% at steps of 10%. Generally, the beam specimens exhibited majorly shear failure with visible diagonal cracks extending from support points to the load points. The corresponding central deflection in beams, due to two points loading, increased as the laterite was added to the concrete mix but reduced and almost approaching that of the control as 10% CCA was added. The deflection then increased as the CCA content further increased to 20%, 30% and 40% in the mix. It was also noted that the deflection of all percentage replacement including 40% CCA is less than the standard recommended maximum deflection of the beam. The optimal flexural strength occurred with 10% CCA content.

2D-3D Face Recognition Method Basedon a Modified CCA-PCA Algorithm

Directory of Open Access Journals (Sweden)

Patrik Kamencay

2014-03-01

Full Text Available This paper presents a proposed methodology for face recognition based on an information theory approach to coding and decoding face images. In this paper, we propose a 2D-3D face-matching method based on a principal component analysis (PCA algorithm using canonical correlation analysis (CCA to learn the mapping between a 2D face image and 3D face data. This method makes it possible to match a 2D face image with enrolled 3D face data. Our proposed fusion algorithm is based on the PCA method, which is applied to extract base features. PCA feature-level fusion requires the extraction of different features from the source data before features are merged together. Experimental results on the TEXAS face image database have shown that the classification and recognition results based on the modified CCA-PCA method are superior to those based on the CCA method. Testing the 2D-3D face match results gave a recognition rate for the CCA method of a quite poor 55% while the modified CCA method based on PCA-level fusion achieved a very good recognition score of 85%.

Efficient KDM-CCA Secure Public-Key Encryption via Auxiliary-Input Authenticated Encryption

Directory of Open Access Journals (Sweden)

Shuai Han

2017-01-01

Full Text Available KDM[F]-CCA security of public-key encryption (PKE ensures the privacy of key-dependent messages f(sk which are closely related to the secret key sk, where f∈F, even if the adversary is allowed to make decryption queries. In this paper, we study the design of KDM-CCA secure PKE. To this end, we develop a new primitive named Auxiliary-Input Authenticated Encryption (AIAE. For AIAE, we introduce two related-key attack (RKA security notions, including IND-RKA and weak-INT-RKA. We present a generic construction of AIAE from tag-based hash proof system (HPS and one-time secure authenticated encryption (AE and give an instantiation of AIAE under the Decisional Diffie-Hellman (DDH assumption. Using AIAE as an essential building block, we give two constructions of efficient KDM-CCA secure PKE based on the DDH and the Decisional Composite Residuosity (DCR assumptions. Specifically, (i our first PKE construction is the first one achieving KDM[Faff]-CCA security for the set of affine functions and compactness of ciphertexts simultaneously. (ii Our second PKE construction is the first one achieving KDM[Fpolyd]-CCA security for the set of polynomial functions and almost compactness of ciphertexts simultaneously. Our PKE constructions are very efficient; in particular, they are pairing-free and NIZK-free.

Changes to timber market

International Nuclear Information System (INIS)

Haluza, I.

2008-01-01

Ten thousands of tree trunks have ended up in the Liptovska Mara lake. The fact that state owned company Lesy SR decided to store the timber in the reservoir as it could not sell it on the market represents a small revolution in the industry. About a year ago timber processing companies were fighting for timber and suddenly it cannot be sold and has to be stored in the reservoir waiting for better times. When the forestry and timber processing industry will not be in such a difficult situation as it is now. Timber, floor and furniture manufacturers claim that the demand for their products and consequently also prices are falling. Some have already started to decrease production and started making redundancies. And when manufacturers complain, the timber suppliers are not happy either. The reason is that the industry has been hit by several blows at the same time. In last three to four years forests in Slovakia, Czech Republic, Austria, Scandinavia and in Canada have suffered several heavy windstorms after which large volumes of timber had to be processed quickly. So there was an excess of timber, particularly spruce. This created an ideal situation for the processing industry where the more agile companies increased their market share and offered timber at more competitive prices. (authors)

Performance of Sprayed Fiber Reinforced Polymer Strengthened Timber Beams

Directory of Open Access Journals (Sweden)

S. Talukdar

2010-01-01

Full Text Available A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51% improvement in load-carrying capacity and a 460% increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.

Modeling Banking, Sovereign, and Macro Risk in a CCA Global VAR

OpenAIRE

Dale F. Gray

2013-01-01

The purpose of this paper is to develop a model framework for the analysis of interactions between banking sector risk, sovereign risk, corporate sector risk, real economic activity, and credit growth for 15 European countries and the United States. It is an integrated macroeconomic systemic risk model framework that draws on the advantages of forward-looking contingent claims analysis (CCA) risk indicators for the banking systems in each country, forward-looking CCA risk indicators for sover...

Damping in Timber Structures

OpenAIRE

Labonnote, Nathalie

2012-01-01

Key point to development of environmentally friendly timber structures, appropriate to urban ways of living, is the development of high-rise timber buildings. Comfort properties are nowadays one of the main limitations to tall timber buildings, and an enhanced knowledge on damping phenomena is therefore required, as well as improved prediction models for damping. The aim of this work has consequently been to estimate various damping quantities in timber structures. In particular, models h...

Determination of chromated copper arsenate (CCA) in treated wood of Eucalyptus

International Nuclear Information System (INIS)

Parreira, Paulo S.; Vendrametto, Guilherme R.; Cunha, Magda E.T.

2009-01-01

This work deals with the possible application of a portable energy dispersive handmade system (PXRF-LFNA-02) for the determination of Chromium, Copper and Arsenic in the preservative solution used to protect commercial wood of Eucalyptus, which are employed as wood fence, posts, contention fences, railroad sleepers, etc. It was prepared five body-of-proof made of eucalyptus alburnum with different concentrations for each element varying from 0.0061 to 0.0180 (g/g) for CrO 3 , 0.0024 to 0.0070 (g/g) for CuO and 0.0044 to 0.0129 (g/g) for As 2 O 5 . Four of them were used for calibration curves and one used as reference sample. It was used a commercial CCA (Chromated Copper Arsenate ) solution to prepare the samples. The results show a good linear regression between concentrations and X-rays intensities, after applied the multiple linear regression methodology for interelemental corrections. The values obtained with this methodology were 3.01(kg/m 3 ), 1.18 (kg/m 3 ) e 2.21 (kg/m 3 ) for CrO 3 , CuO and As 2 O 5 , respectively, while the nominal values are 2.90 (kg/m 3 ) for CrO 3 , 1.13 (kg/m 3 ) for CuO and 2.07 (kg/m 3 ) for As 2 O 5 . The ED-XRF (Energy Dispersive X-Rays Fluorescence) is a well established technique with high-speed of analytical procedure and its portable configuration allowing a multielemental, simultaneous and non destructive analyses besides in situ application. (author)

Rapid microwave-assisted acid extraction of southern pine waste wood to remove metals from chromated copper arsenate (CCA) treatment

Science.gov (United States)

Chung-Yun Hse; Todd F. Shupe; Bin Yu

2013-01-01

Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated by extraction in a microwave reactor with binary combinations of acetic acid (AA), oxalic acid (OxA), and phosphoric acid (PhA). Use of OxA was not successful, as insoluble copper oxalate complexes impeded copper removal. The combination of OxA and AA also had...

Developing multi-cellular tumor spheroid model (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening

Energy Technology Data Exchange (ETDEWEB)

Wang, Jian-Zheng, E-mail: wppzheng@126.com [Laboratory of Biomedical Material Engineering, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Affiliated General Hospital, Tianguan Group Co., Ltd, Nanyang 473000 (China); Testing Center of Henan Tianguan Group Co., Ltd, Nanyang 473000 (China); Zhu, Yu-Xia [Laboratory of Biomedical Material Engineering, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Affiliated General Hospital, Tianguan Group Co., Ltd, Nanyang 473000 (China); Testing Center of Henan Tianguan Group Co., Ltd, Nanyang 473000 (China); Ma, Hui-Chao; Chen, Si-Nan; Chao, Ji-Ye; Ruan, Wen-Ding; Wang, Duo; Du, Feng-guang [Affiliated General Hospital, Tianguan Group Co., Ltd, Nanyang 473000 (China); Testing Center of Henan Tianguan Group Co., Ltd, Nanyang 473000 (China); Meng, Yue-Zhong [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275 (China)

2016-05-01

In this work, a 3D MCTS-CCA system was constructed by culturing multi-cellular tumor spheroid (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening. The CCA scaffolds were fabricated by spray-spinning. The interactions between the components of the spray-spun fibers were evidenced by methods of Coomassie Blue stain, X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR). Co-culture indicated that MCF-7 cells showed a spatial growth pattern of multi-cellular tumor spheroid (MCTS) in the CCA fibrous scaffold with increased proliferation rate and drug-resistance to MMC, ADM and 5-Aza comparing with the 2D culture cells. Significant increases of total viable cells were found in 3D MCTS groups after drug administration by method of apoptotic analysis. Glucose–lactate analysis indicated that the metabolism of MCTS in CCA scaffold was closer to the tumor issue in vivo than the monolayer cells. In addition, MCTS showed the characteristic of epithelial mesenchymal transition (EMT) which is subverted by carcinoma cells to facilitate metastatic spread. These results demonstrated that MCTS in CCA scaffold possessed a more conservative phenotype of tumor than monolayer cells, and anticancer drug screening in 3D MCTS-CCA system might be superior to the 2D culture system. - Highlights: • Chitosan/collagen/alginate (CCA) scaffolds were fabricated by spray-spinning. • MCF-7 cells presented a multi-cellular tumor spheroid model (MCTS) in CCA scaffold. • MCTS in CCA possessed a more conservative phenotype of tumor than monolayer cells. • Anticancer drug screening in MCTS-CCA system is superior to 2D culture system.

Developing multi-cellular tumor spheroid model (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening

International Nuclear Information System (INIS)

Wang, Jian-Zheng; Zhu, Yu-Xia; Ma, Hui-Chao; Chen, Si-Nan; Chao, Ji-Ye; Ruan, Wen-Ding; Wang, Duo; Du, Feng-guang; Meng, Yue-Zhong

2016-01-01

In this work, a 3D MCTS-CCA system was constructed by culturing multi-cellular tumor spheroid (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening. The CCA scaffolds were fabricated by spray-spinning. The interactions between the components of the spray-spun fibers were evidenced by methods of Coomassie Blue stain, X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR). Co-culture indicated that MCF-7 cells showed a spatial growth pattern of multi-cellular tumor spheroid (MCTS) in the CCA fibrous scaffold with increased proliferation rate and drug-resistance to MMC, ADM and 5-Aza comparing with the 2D culture cells. Significant increases of total viable cells were found in 3D MCTS groups after drug administration by method of apoptotic analysis. Glucose–lactate analysis indicated that the metabolism of MCTS in CCA scaffold was closer to the tumor issue in vivo than the monolayer cells. In addition, MCTS showed the characteristic of epithelial mesenchymal transition (EMT) which is subverted by carcinoma cells to facilitate metastatic spread. These results demonstrated that MCTS in CCA scaffold possessed a more conservative phenotype of tumor than monolayer cells, and anticancer drug screening in 3D MCTS-CCA system might be superior to the 2D culture system. - Highlights: • Chitosan/collagen/alginate (CCA) scaffolds were fabricated by spray-spinning. • MCF-7 cells presented a multi-cellular tumor spheroid model (MCTS) in CCA scaffold. • MCTS in CCA possessed a more conservative phenotype of tumor than monolayer cells. • Anticancer drug screening in MCTS-CCA system is superior to 2D culture system.

Transgenic plants expressing GLK1 and CCA1 having increased nitrogen assimilation capacity

Science.gov (United States)

Coruzzi, Gloria [New York, NY; Gutierrez, Rodrigo A [Santiago, CL; Nero, Damion C [Woodside, NY

2012-04-10

Provided herein are compositions and methods for producing transgenic plants. In specific embodiments, transgenic plants comprise a construct comprising a polynucleotide encoding CCA1, GLK1 or bZIP1, operably linked to a plant-specific promote, wherein the CCA1, GLK1 or bZIP1 is ectopically overexpressed in the transgenic plants, and wherein the promoter is optionally a constitutive or inducible promoter. In other embodiments, transgenic plants in which express a lower level of CCA1, GLK1 or bZIP1 are provided. Also provided herein are commercial products (e.g., pulp, paper, paper products, or lumber) derived from the transgenic plants (e.g., transgenic trees) produced using the methods provided herein.

Timber Products Supply and Demand

Science.gov (United States)

Jeffrey P. Prestemon; Robert C. Abt

2002-01-01

This chapter describes historical, current, and projected timber inventories and timber product outputs from southern forests. It also attempts to place these quantities in national and international perspectives. Timber is the most valuable commercial commodity taken from most forests, and its removal strongly influences the character of those forests. Timber is...

Timber products output and timber harvests in Alaska: projections for 1992-2010.

Science.gov (United States)

D.J. Brooks; R.W. Haynes

1994-01-01

Projections of Alaska timber products output, the derived demand for raw material, and timber harvest by owner are developed from a trend-based analysis. By using a spread-sheet model, material flows in the Alaska forest sectorare fully accounted for. Demand for Alaska national forest timber is projected and depends on product output and harvest by other owners. Key...

Timber value—a matter of choice: a study of how end use assumptions affect timber values.

Science.gov (United States)

John H. Beuter

1971-01-01

The relationship between estimated timber values and actual timber prices is discussed. Timber values are related to how, where, and when the timber is used. An analysis demonstrates the relative values of a typical Douglas-fir stand under assumptions about timber use.

Timber management planning with timber ram and goal programming

Science.gov (United States)

Richard C. Field

1978-01-01

By using goal programming to enhance the linear programming of Timber RAM, multiple decision criteria were incorporated in the timber management planning of a National Forest in the southeastern United States. Combining linear and goal programming capitalizes on the advantages of the two techniques and produces operationally feasible solutions. This enhancement may...

Determination of chromated copper arsenate (CCA) in treated wood of Eucalyptus

Energy Technology Data Exchange (ETDEWEB)

Parreira, Paulo S., E-mail: parreira@uel.b [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Fisica. Lab.de Fisica Nuclear Aplicada; Vendrametto, Guilherme R.; Cunha, Magda E.T., E-mail: grvendrametto@gmail.co [Universidade Norte do Parana, Arapongas, PR (Brazil). Centro de Ciencias Humanas, da Saude, Exatas e Tecnologicas-A

2009-07-01

This work deals with the possible application of a portable energy dispersive handmade system (PXRF-LFNA-02) for the determination of Chromium, Copper and Arsenic in the preservative solution used to protect commercial wood of Eucalyptus, which are employed as wood fence, posts, contention fences, railroad sleepers, etc. It was prepared five body-of-proof made of eucalyptus alburnum with different concentrations for each element varying from 0.0061 to 0.0180 (g/g) for CrO{sub 3}, 0.0024 to 0.0070 (g/g) for CuO and 0.0044 to 0.0129 (g/g) for As{sub 2}O{sub 5}. Four of them were used for calibration curves and one used as reference sample. It was used a commercial CCA (Chromated Copper Arsenate ) solution to prepare the samples. The results show a good linear regression between concentrations and X-rays intensities, after applied the multiple linear regression methodology for interelemental corrections. The values obtained with this methodology were 3.01(kg/m{sup 3}), 1.18 (kg/m{sup 3}) e 2.21 (kg/m{sup 3}) for CrO{sub 3}, CuO and As{sub 2}O{sub 5}, respectively, while the nominal values are 2.90 (kg/m{sup 3}) for CrO{sub 3}, 1.13 (kg/m{sup 3}) for CuO and 2.07 (kg/m{sup 3}) for As{sub 2}O{sub 5}. The ED-XRF (Energy Dispersive X-Rays Fluorescence) is a well established technique with high-speed of analytical procedure and its portable configuration allowing a multielemental, simultaneous and non destructive analyses besides in situ application. (author)

Accuracy of urine circulating cathodic antigen (CCA test for Schistosoma mansoni diagnosis in different settings of Côte d'Ivoire.

Directory of Open Access Journals (Sweden)

Jean T Coulibaly

2011-11-01

Full Text Available BACKGROUND: Promising results have been reported for a urine circulating cathodic antigen (CCA test for the diagnosis of Schistosoma mansoni. We assessed the accuracy of a commercially available CCA cassette test (designated CCA-A and an experimental formulation (CCA-B for S. mansoni diagnosis. METHODOLOGY: We conducted a cross-sectional survey in three settings of Côte d'Ivoire: settings A and B are endemic for S. mansoni, whereas S. haematobium co-exists in setting C. Overall, 446 children, aged 8-12 years, submitted multiple stool and urine samples. For S. mansoni diagnosis, stool samples were examined with triplicate Kato-Katz, whereas urine samples were tested with CCA-A. The first stool and urine samples were additionally subjected to an ether-concentration technique and CCA-B, respectively. Urine samples were examined for S. haematobium using a filtration method, and for microhematuria using Hemastix dipsticks. PRINCIPAL FINDINGS: Considering nine Kato-Katz as diagnostic 'gold' standard, the prevalence of S. mansoni in setting A, B and C was 32.9%, 53.1% and 91.8%, respectively. The sensitivity of triplicate Kato-Katz from the first stool and a single CCA-A test was 47.9% and 56.3% (setting A, 73.9% and 69.6% (setting B, and 94.2% and 89.6% (setting C. The respective sensitivity of a single CCA-B was 10.4%, 29.9% and 75.0%. The ether-concentration technique showed a low sensitivity for S. mansoni diagnosis (8.3-41.0%. The specificity of CCA-A was moderate (76.9-84.2%; CCA-B was high (96.7-100%. The likelihood of a CCA-A color reaction increased with higher S. mansoni fecal egg counts (odds ratio: 1.07, p<0.001. A concurrent S. haematobium infection or the presence of microhematuria did not influence the CCA-A test results for S. mansoni diagnosis. CONCLUSION/SIGNIFICANCE: CCA-A showed similar sensitivity than triplicate Kato-Katz for S. mansoni diagnosis with no cross-reactivity to S. haematobium and microhematuria. The low sensitivity

The 1993 RPA timber assessment update

Science.gov (United States)

Richard W. Haynes; Darius M. Adams; John R. Mills

1995-01-01

This update reports changes in the Nation's timber resource since the 1989 RPA timber assessment. The timber resource situation is analyzed to provide projections for future cost and availability of timber products to meet demands. Prospective trends in demands for and supplies of timber, and the factors that affect these trends are examined. These include changes...

Global sustainable timber supply and demand

Science.gov (United States)

Peter J. Ince

2010-01-01

Industrial timber use has provided timber revenue that has helped make timber supply and demand more sustainable in the leading timber producing regions of the world. Sustainable development implies not consuming more resources today than we can replace tomorrow, but sustainable forest management implies more than merely a non-declining supply of timber. Forests as a...

Systems approach identifies an organic nitrogen-responsive gene network that is regulated by the master clock control gene CCA1.

Science.gov (United States)

Gutiérrez, Rodrigo A; Stokes, Trevor L; Thum, Karen; Xu, Xiaodong; Obertello, Mariana; Katari, Manpreet S; Tanurdzic, Milos; Dean, Alexis; Nero, Damion C; McClung, C Robertson; Coruzzi, Gloria M

2008-03-25

Understanding how nutrients affect gene expression will help us to understand the mechanisms controlling plant growth and development as a function of nutrient availability. Nitrate has been shown to serve as a signal for the control of gene expression in Arabidopsis. There is also evidence, on a gene-by-gene basis, that downstream products of nitrogen (N) assimilation such as glutamate (Glu) or glutamine (Gln) might serve as signals of organic N status that in turn regulate gene expression. To identify genome-wide responses to such organic N signals, Arabidopsis seedlings were transiently treated with ammonium nitrate in the presence or absence of MSX, an inhibitor of glutamine synthetase, resulting in a block of Glu/Gln synthesis. Genes that responded to organic N were identified as those whose response to ammonium nitrate treatment was blocked in the presence of MSX. We showed that some genes previously identified to be regulated by nitrate are under the control of an organic N-metabolite. Using an integrated network model of molecular interactions, we uncovered a subnetwork regulated by organic N that included CCA1 and target genes involved in N-assimilation. We validated some of the predicted interactions and showed that regulation of the master clock control gene CCA1 by Glu or a Glu-derived metabolite in turn regulates the expression of key N-assimilatory genes. Phase response curve analysis shows that distinct N-metabolites can advance or delay the CCA1 phase. Regulation of CCA1 by organic N signals may represent a novel input mechanism for N-nutrients to affect plant circadian clock function.

Traditional timber frames

NARCIS (Netherlands)

Jorissen, A.J.M.; Hamer, den J.; Leijten, A.J.M.; Salenikovich, A.

2014-01-01

Due to new possibilities traditional timber framing has become increasingly popular since the beginning of the 21e century. Although traditional timber framing has been used for centuries, the expected mechanical behaviour is not dealt with in great detail in building codes, guidelines or text

Timber resources of southwest Oregon.

Science.gov (United States)

Patricia M. Bassett

1979-01-01

This report presents statistics from a 1973 inventory of timber resources of Douglas County and from a 1974 inventory of timber resources of Coos, Curry, Jackson, and Josephine Counties, Oregon. Tables presented are of forest area and of timber volume, growth, and mortality.

Computer Vision for Timber Harvesting

DEFF Research Database (Denmark)

Dahl, Anders Lindbjerg

The goal of this thesis is to investigate computer vision methods for timber harvesting operations. The background for developing computer vision for timber harvesting is to document origin of timber and to collect qualitative and quantitative parameters concerning the timber for efficient harvest...... segments. The purpose of image segmentation is to make the basis for more advanced computer vision methods like object recognition and classification. Our second method concerns image classification and we present a method where we classify small timber samples to tree species based on Active Appearance...... to the development of the logTracker system the described methods have a general applicability making them useful for many other computer vision problems....

Development of Timber Property Classification Based on the End-Use with Reference to Twenty Sri Lankan Timber Species

Directory of Open Access Journals (Sweden)

ND Ruwanpathirana

2014-06-01

Full Text Available An investigation was carried out on selected 20 timber species of Sri Lanka to study different wood properties, i.e., wood density, modulus of rapture, modulus of elasticity, compression parallel to grain, shrinkage/movement, workability (sawing, nailing, sanding and finishing, treatability of preservative, timber durability, timber texture by vessel diameter and some gross properties, timber colour and present timber uses. Based on the results, an attempt was made to classify the studied timber species into property levels. The final objective of this study was to develop relationships between the end-uses of timber and their property requirements and levels with reference to 20 Sri Lankan timber species.   Timber selection for the use in Sri Lanka is species-oriented and sometimes it is based on the traditional use. Based on wood properties of 20 Sri Lankan timber species selected, an attempt was made to recognise the most important wood properties and their levels to develop a four end-use property classification. In general, the proposed end-use property classification in this study could be differentiated as (i. for building construction, (ii. for furniture and joinery (iii. for light construction, and (iv. for miscellaneous uses. Among the selected timber species, Dipterocarpus zeylanicus is eminently suitable for under-water work. Eucalyptus microcorys is regarded as one of the best timbers for dancing floors. These specialty and causative factors of timber, however, must be explored and documented in order to prepare end-use property classification for miscellaneous use.

Narrowing the Broader Autism Phenotype: A Study Using the Communication Checklist-Adult Version (CC-A)

Science.gov (United States)

Whitehouse, Andrew J. O.; Coon, Hilary; Miller, Judith; Salisbury, Bryanna; Bishop, Dorothy V. M.

2010-01-01

This study investigated whether the Communication Checklist-Adult (CC-A) could identify subtypes of social and communication dysfunction in autism probands and their parents. The CC-A is divided into subscales measuring linguistic ability as well as two aspects of social communication: the Pragmatic Skills subscale assesses the level of pragmatic…

Section of mechanized timbering

Energy Technology Data Exchange (ETDEWEB)

Balaganskiy, S Ye; Aksanov, Sh I; Ardashev, K A; Mednik, L Ye; Mikhaylov, P G

1980-09-05

A section of mechanized timbering is claimed which contains a base, roof timber, hydraulic stand, hydraulic packing cylinders, packing telescopic shield hinged to the roof timber by means of guides. To improve the reliability of forming the filling massif, the packing telescopic shield is made in the form of individual telescopic beams with guards which are interconnected by means of cross beams, while the gaps between the telescopic beams are covered with elasic plates.

Role of the CCA bulge of prohead RNA of bacteriophage ø29 in DNA packaging.

Science.gov (United States)

Zhao, Wei; Morais, Marc C; Anderson, Dwight L; Jardine, Paul J; Grimes, Shelley

2008-11-14

The oligomeric ring of prohead RNA (pRNA) is an essential component of the ATP-driven DNA packaging motor of bacteriophage ø29. The A-helix of pRNA binds the DNA translocating ATPase gp16 (gene product 16) and the CCA bulge in this helix is essential for DNA packaging in vitro. Mutation of the bulge by base substitution or deletion showed that the size of the bulge, rather than its sequence, is primary in DNA packaging activity. Proheads reconstituted with CCA bulge mutant pRNAs bound the packaging ATPase gp16 and the packaging substrate DNA-gp3, although DNA translocation was not detected with several mutants. Prohead/bulge-mutant pRNA complexes with low packaging activity had a higher rate of ATP hydrolysis per base pair of DNA packaged than proheads with wild-type pRNA. Cryoelectron microscopy three-dimensional reconstruction of proheads reconstituted with a CCA deletion pRNA showed that the protruding pRNA spokes of the motor occupy a different position relative to the head when compared to particles with wild-type pRNA. Therefore, the CCA bulge seems to dictate the orientation of the pRNA spokes. The conformational changes observed for this mutant pRNA may affect gp16 conformation and/or subsequent ATPase-DNA interaction and, consequently, explain the decreased packaging activity observed for CCA mutants.

kCCA Transformation-Based Radiometric Normalization of Multi-Temporal Satellite Images

Directory of Open Access Journals (Sweden)

Yang Bai

2018-03-01

Full Text Available Radiation normalization is an essential pre-processing step for generating high-quality satellite sequence images. However, most radiometric normalization methods are linear, and they cannot eliminate the regular nonlinear spectral differences. Here we introduce the well-established kernel canonical correlation analysis (kCCA into radiometric normalization for the first time to overcome this problem, which leads to a new kernel method. It can maximally reduce the image differences among multi-temporal images regardless of the imaging conditions and the reflectivity difference. It also perfectly eliminates the impact of nonlinear changes caused by seasonal variation of natural objects. Comparisons with the multivariate alteration detection (CCA-based normalization and the histogram matching, on Gaofen-1 (GF-1 data, indicate that the kCCA-based normalization can preserve more similarity and better correlation between an image-pair and effectively avoid the color error propagation. The proposed method not only builds the common scale or reference to make the radiometric consistency among GF-1 image sequences, but also highlights the interesting spectral changes while eliminates less interesting spectral changes. Our method enables the application of GF-1 data for change detection, land-use, land-cover change detection etc.

Pennsylvania hardwood timber bridges : field performance after 10 years

Science.gov (United States)

James P. Wacker; Carlito Calil

2004-01-01

Several hardwood demonstration timber bridges were built by the Pennsylvania Department of Transportation in the early nineteen nineties. These bridge superstructures are of the recently developed stress-laminated deck design-type using Red Oak lumber laminations that were pressure-treated with creosote preservatives. This paper will describe the data acquisition...

Timber salvage economics

Science.gov (United States)

Jeffrey P. Prestemon; Thomas P. Holmes

2008-01-01

Timber salvage is commonly done following natural disturbances, to recover some value from damaged forests. Decision making about salvage, however, is affected by ownership objectives, the nature of the damage agent, site factors, and the strength of the local timber market. For profit-maximizing landowners, salvage decisions must balance the cost of harvesting...

Occupational exposure to chromium, copper and arsenic during work with impregnated wood in joinery shops.

Science.gov (United States)

Nygren, O; Nilsson, C A; Lindahl, R

1992-10-01

CCA-impregnated timber contains copper, chromium and arsenic (CCA), and occupational exposure to wood dust as well as the CCA compounds may occur in work with such timber. Dust from commercially available impregnated wood has been found to contain hexavalent chromium, which is regarded as a carcinogen. Apart from determinations of the total amounts of the CCA compounds, specific determination of hexavalent chromium is therefore essential. Selective methods have been applied for control of the work environment in six joinery shops. The mean exposure to wood dust was found to be below 1 mg m-3. The mean airborne concentration of arsenic around various types of joinery machines was in the range from 0.54 to 3.1 micrograms m-3. No hexavalent chromium was detected in any samples and no increased concentrations of arsenic were found in urine from the workers. The presence of arsenic in the work-room air must be considered for appropriate assessment of the occupational environment in joinery shops.

Developing multi-cellular tumor spheroid model (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening.

Science.gov (United States)

Wang, Jian-Zheng; Zhu, Yu-Xia; Ma, Hui-Chao; Chen, Si-Nan; Chao, Ji-Ye; Ruan, Wen-Ding; Wang, Duo; Du, Feng-guang; Meng, Yue-Zhong

2016-05-01

In this work, a 3D MCTS-CCA system was constructed by culturing multi-cellular tumor spheroid (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening. The CCA scaffolds were fabricated by spray-spinning. The interactions between the components of the spray-spun fibers were evidenced by methods of Coomassie Blue stain, X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR). Co-culture indicated that MCF-7 cells showed a spatial growth pattern of multi-cellular tumor spheroid (MCTS) in the CCA fibrous scaffold with increased proliferation rate and drug-resistance to MMC, ADM and 5-Aza comparing with the 2D culture cells. Significant increases of total viable cells were found in 3D MCTS groups after drug administration by method of apoptotic analysis. Glucose-lactate analysis indicated that the metabolism of MCTS in CCA scaffold was closer to the tumor issue in vivo than the monolayer cells. In addition, MCTS showed the characteristic of epithelial mesenchymal transition (EMT) which is subverted by carcinoma cells to facilitate metastatic spread. These results demonstrated that MCTS in CCA scaffold possessed a more conservative phenotype of tumor than monolayer cells, and anticancer drug screening in 3D MCTS-CCA system might be superior to the 2D culture system. Copyright © 2016 Elsevier B.V. All rights reserved.

The Timber Resource Inventory Model (TRIM): a projection model for timber supply and policy analysis.

Science.gov (United States)

P.L. Tedder; R.N. La Mont; J.C. Kincaid

1987-01-01

TRIM (Timber Resource Inventory Model) is a yield table projection system developed for timber supply projections and policy analysis. TRIM simulates timber growth, inventories, management and area changes, and removals over the projection period. Programs in the TRIM system, card-by-card descriptions of required inputs, table formats, and sample results are presented...

The timber resources of Rhode Island

Science.gov (United States)

Roland H. Ferguson; John R. McGuire; John R. McGuire

1957-01-01

This is a report on the first comprehensive survey ever made of the timber resources of Rhode Island. It shows, for the years 1952 and 1953, the area and condition of the forest land, the volume and quality of standing timber, the rates of timber growth and mortality, and the extent of timber cutting for forest products. The survey was made by the Forest Service as...

CSMA/CCA: A Modified CSMA/CA Protocol Mitigating the Fairness Problem for IEEE 802.11 DCF

Directory of Open Access Journals (Sweden)

Wang Xin

2006-01-01

Full Text Available Carrier sense multiple access with collision avoidance (CSMA/CA has been adopted by the IEEE 802.11 standards for wireless local area networks (WLANs. Using a distributed coordination function (DCF, the CSMA/CA protocol reduces collisions and improves the overall throughput. To mitigate fairness issues arising with CSMA/CA, we develop a modified version that we term CSMA with copying collision avoidance (CSMA/CCA. A station in CSMA/CCA contends for the shared wireless medium by employing a binary exponential backoff similar to CSMA/CA. Different from CSMA/CA, CSMA/CCA copies the contention window (CW size piggybacked in the MAC header of an overheard data frame within its basic service set (BSS and updates its backoff counter according to the new CW size. Simulations carried out in several WLAN configurations illustrate that CSMA/CCA improves fairness relative to CSMA/CA and offers considerable advantages for deployment in the 802.11-standard-based WLANs.

Timber Curtain

DEFF Research Database (Denmark)

2015-01-01

Timber Curtain is a site specific architectural installation, which is part of a research project conducted at the Aarhus School of Architecture as collaboration between Ph.D. and associate professor Niels Martin Larsen and the author. Through a digitally scripted associative model we performed s...... of pinewood timber, machined with a CMS Antares 5-axis CNC router. The digital process generation and simulation was implemented with Rhinoceros 3D, Grasshopper and GHPython, and AlphaCAM was used for preparing the CNC-routing....

Probabilistic modeling of timber structures

DEFF Research Database (Denmark)

Köhler, Jochen; Sørensen, John Dalsgaard; Faber, Michael Havbro

2007-01-01

The present paper contains a proposal for the probabilistic modeling of timber material properties. It is produced in the context of the Probabilistic Model Code (PMC) of the Joint Committee on Structural Safety (JCSS) [Joint Committee of Structural Safety. Probabilistic Model Code, Internet...... Publication: www.jcss.ethz.ch; 2001] and of the COST action E24 ‘Reliability of Timber Structures' [COST Action E 24, Reliability of timber structures. Several meetings and Publications, Internet Publication: http://www.km.fgg.uni-lj.si/coste24/coste24.htm; 2005]. The present proposal is based on discussions...... and comments from participants of the COST E24 action and the members of the JCSS. The paper contains a description of the basic reference properties for timber strength parameters and ultimate limit state equations for timber components. The recommended probabilistic model for these basic properties...

Timber in Bridge Structures

OpenAIRE

Detkin, Viktoria

2016-01-01

The purpose of this final year project was to study the properties of timber as a structural material and the suitability of wood in load bearing members for bridge structures. For a case study, an existing timber bridge was selected. Due to its condition the bridge should be replaced. The design of a new bridge with steel beams holding a glulam deck was made. During the case study the replacement of steel beams by glulam timber ones was discussed. Some calculations were made in order to ...

Alabama's timber industry - an assessment of timber product output and use, 1995

Science.gov (United States)

Tony G. Johnson; Jim R. Gober; J. Stephen Nix

1998-01-01

Output of Industrial Timber Products.Note: The reader must understand that certain terms, namely-retained, export, import, production, and receipts-have specialized meanings and relationships. unique to the Forest Inventory and Analysis Units across the country that deal with timber products output.In 1995, the combined...

Three-dimensional dynamic magnetic resonance angiography for the evaluation of radiosurgically treated cerebral arteriovenous malformations

International Nuclear Information System (INIS)

Gauvrit, Jean-Yves; Oppenheim, Catherine; Naggara, Olivier; Trystram, Denis; Fredy, Daniel; Meder, Jean-Francois; Nataf, Francois; Roux, Francois-Xavier; Munier, Thierry; Pruvo, Jean-Pierre; Leclerc, Xavier

2006-01-01

We assessed the value of three-dimensional (3D) dynamic magnetic resonance angiography (MRA) for the follow-up of patients with radiosurgically treated cerebral arteriovenous malformations (AVMs). Fifty-four patients with cerebral AVMs treated by radiosurgery (RS) were monitored using conventional catheter angiography (CCA) and 3D dynamic MRA with sensitivity encoding based on the parallel imaging. Cerebral AVM was qualitatively classified by two radiologists into one of five categories in terms of residual nidus size and persistence of early draining vein (I, >6 cm; II, 3-6 cm; III, <3 cm; IV, isolated early draining vein; V, complete obliteration). 3D MRA findings showed a good agreement with CCA in 40 cases (κ=0.62). Of 23 nidus detected on CCA, 3D dynamic MRA showed 14 residual nidus. Of 28 occluded nidus on 3D dynamic MRA, 22 nidus were occluded on CCA. The sensitivity and specificity of 3D dynamic MRA for the detection of residual AVM were 81% and 100%. 3D dynamic MRA after RS may therefore be useful in association with MRI and can be repeated as long as opacification of the nidus or early venous drainage persists, one CCA remaining indispensable to affirm the complete occlusion at the end of follow-up. (orig.)

timber for structural use

African Journals Online (AJOL)

HOD

Logs of Apa timber were air-dried and along the stem, 324 pieces of test specimens were ..... (machine) manual with the load rate of 1mm/min ..... [16] Desch, H. E., Timber properties, 6th. Edition,. Revised by J. M. Dinwoodie. Macmillan ...

Music recommendation according to human motion based on kernel CCA-based relationship

Science.gov (United States)

Ohkushi, Hiroyuki; Ogawa, Takahiro; Haseyama, Miki

2011-12-01

In this article, a method for recommendation of music pieces according to human motions based on their kernel canonical correlation analysis (CCA)-based relationship is proposed. In order to perform the recommendation between different types of multimedia data, i.e., recommendation of music pieces from human motions, the proposed method tries to estimate their relationship. Specifically, the correlation based on kernel CCA is calculated as the relationship in our method. Since human motions and music pieces have various time lengths, it is necessary to calculate the correlation between time series having different lengths. Therefore, new kernel functions for human motions and music pieces, which can provide similarities between data that have different time lengths, are introduced into the calculation of the kernel CCA-based correlation. This approach effectively provides a solution to the conventional problem of not being able to calculate the correlation from multimedia data that have various time lengths. Therefore, the proposed method can perform accurate recommendation of best matched music pieces according to a target human motion from the obtained correlation. Experimental results are shown to verify the performance of the proposed method.

Advancing Coordination Between DRM and CCA in Integrated Flood Risk Management

DEFF Research Database (Denmark)

Jebens, Martin; Sørensen, Carlo Sass

Flood hazards in coastal regions induce risks toward lives, property, economy and the environment. In need of sustainable and holistic actions to reduce risks, these should include innovative Disaster Risk Management (DRM) and Climate Change Adaptation (CCA) measures. While differing on important...... flood events to exert pressure on the national government, and in a top-down approach the government could identify the needs among the civil society to include these in the decision-making process.......-structural measures is hampered by lack in coordination that should be improved to agree e.g. on an acceptable risk definition and to avoid duplicating efforts. To advance awareness and coordination between DRM and CCA and to improve measures, a bottom-up approach could by initiated by civil society using recent...

The impact of ultraviolet radiation on timber

International Nuclear Information System (INIS)

Dawson, B.

1993-01-01

Photochemical degradation of timber, the outcome of exposure of timber to ultraviolet radiation, is a light induced chemical and physical decay. Timber is a collection of dead wood cells. Impacts of radiation on the growing tree are therefore outside the scope of this paper, which is primarily concerned with timber as a material. (author). 5 refs. 2 figs

Evaluation of circulating cathodic antigen (CCA strip for diagnosis of urinary schistosomiasis in Hassoba school children, Afar, Ethiopia

Directory of Open Access Journals (Sweden)

Ayele B.

2008-03-01

Full Text Available A total of 206 urine samples collected from Hassoba Elementary schoolchildren, Afar, Ethiopia, a low Schistosoma haematobium endemic setting, was diagnosed to evaluate the performance of CCA strip using double references, urine filtration technique and urinalysis dipstick (Combur 10 Test® that detect schistosome eggs and blood in urine, respectively. The former was used as a gold standard reference method. Sensitivity, specificity, positive and negative predictive values for the CCA were 52%, 63.8%, 56.7% and 59% respectively, with reference to urine filtration technique whereas these parameters were 50.4%, 62.4%, 55.6% and 57.5% respectively, with reference to Combur 10 Test®. 47 S. haematobium egg-positive children were found negative by CCA strip while 38 egg-negative children were found positive by CCA strip. Moreover, among the pre-tests done in duplicate, inconsistent results were also recorded. Assays were also compared with regard to the cost of equipment and reagents, speed and simplicity of use. Though CCA strip was found to be rapid and could be performed with minimal training, it was found to be expensive (US $ 4.95 per test to use it for large-scale field use even if its diagnostic value would have been satisfactory. Further development and standardization of the CCA strip are required for its applicability for field use. It is also recommended that its cost per strip should be substantially cut down if it is to be used in poor schistosomiasis endemic countries.

Chinese adaptation of Emotion Regulation Questionnaire for Children and Adolescents (ERQ-CCA): A psychometric evaluation in Chinese children.

Science.gov (United States)

Liu, Wen; Chen, Liang; Tu, Xintian

2017-10-01

This study validated a Chinese adaptation of the Emotion Regulation Questionnaire for Children and Adolescents (ERQ-CCA), a self-report instrument that evaluates two emotion regulation (ER) strategies, based on the process model of ER. The ERQ-CCA was evaluated using a sample of 1381 Chinese children aged between 7 and 12 years. The internal consistencies of the two factors indicated adequate reliability. Confirmatory factor analysis (CFA) revealed good support as the structure proved to be identical with that of the original instrument. Multigroup CFA supported an invariant factor solution of the ERQ-CCA across several demographic variations (gender, age, registered permanent residence and migrant status) in different groups. Test-retest correlations over a 2-month period were calculated using a subsample of children (N = 70). Convergent validity was evaluated in relation to the model dimensions of the ERQ-CCA, Chinese version of the Children's Depression Inventory, and Chinese version of the Eysenck Personality Questionnaire for Children and Adolescents. Results indicated that the ERQ-CCA has generally satisfactory reliability and validity in investigating the use of two ER strategies during the middle childhood developmental period. © 2015 International Union of Psychological Science.

Monitoring of timber structures: Editorial

OpenAIRE

Kurz, Jochen Horst

2015-01-01

Timber structures have been in use for centuries, with proven durability. In recent years, timber has become particularly important, due to its standing as a truly renewable material for construction and carbon storage purposes. The material behaviour of wood is known and understood. The current design concepts for timber structures are also well developed. Nevertheless, the underlying processes of the ageing and deterioration of wood are complex, and the anisotropic structure of wood require...

Curved Folded Plate Timber Structures

OpenAIRE

Buri, Hans Ulrich; Stotz, Ivo; Weinand, Yves

2011-01-01

This work investigates the development of a Curved Origami Prototype made with timber panels. In the last fifteen years the timber industry has developed new, large size, timber panels. Composition and dimensions of these panels and the possibility of milling them with Computer Numerical Controlled machines shows great potential for folded plate structures. To generate the form of these structures we were inspired by Origami, the Japanese art of paper folding. Common paper tessellations are c...

Copper tolerance of brown-rot fungi : oxalic acid production in southern pine treated with arsenic-free preservatives

Science.gov (United States)

Frederick Green; Carol A. Clausen

2005-01-01

The voluntary withdrawal of chromated copper arsenate (CCA)-treated wood from most residential applications has increased the use of non-arsenical copper-based organic wood preservatives. Because the arsenic component of CCA controlled copper tolerant fungi, scientists have renewed interest in and concern about the decay capacity in the important copper-tolerant group...

Narrowing the broader autism phenotype: A study using the Communication Checklist - Adult Version (CC-A)

OpenAIRE

Whitehouse, AJ; Coon, H; Miller, J; Salisbury, B; Bishop, DV

2010-01-01

This study investigated whether the Communication Checklist – Adult (CC-A) could identify subtypes of social and communication dysfunction in autism probands and their parents. The CC-A is divided into subscales measuring linguistic ability as well as two aspects of social communication: the Pragmatic Skills subscale assesses the level of pragmatic oddities (e.g., excessive talking), while the Social Engagement subscale picks up on those behaviours that reflect a more passive communication st...

The 2005 RPA timber assessment update.

Science.gov (United States)

Richard W. Haynes; Darius M. Adams; Ralph J. Alig; Peter J. Ince; John R. Mills; Xiaoping. Zhou

2007-01-01

This update reports changes in the Nation's timber resource since the Analysis of the Timber Situation in the United States was completed in 2003. Prospective trends in demands for and supplies of timber, and the factors that affect these trends are examined. These trends include changes in the U.S. economy, increased salvage of British Columbia beetle-killed...

1970 Oregon timber harvest.

Science.gov (United States)

Brian R. Wall

1971-01-01

The 1970 Oregon timber harvest of 7.98 billion board feet was the lowest recorded since the recession year of 1961 when 7.41 billion board feet of timber was produced. The 1970 log production figure was 12.8 percent below the 1969 harvest, the second consecutive year of declining production in Oregon.

Robustness Evaluation of Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; čizmar, D.

2010-01-01

The present paper outlines results from working group 3 (WG3) in the EU COST Action E55 – ‘Modelling of the performance of timber structures’. The objectives of the project are related to the three main research activities: the identification and modelling of relevant load and environmental...... exposure scenarios, the improvement of knowledge concerning the behaviour of timber structural elements and the development of a generic framework for the assessment of the life-cycle vulnerability and robustness of timber structures....

Inventory analysis of the timber industry in Ghana

NARCIS (Netherlands)

Eshun, J.F.; Potting, J.; Leemans, R.

2010-01-01

Background, aim, and scope The timber sector, i.e., forestry and timber industry, plays an important role in the socioeconomic development of Ghana through timber products export. Timber production in this sector is associated with increasing environmental burdens in terms of use of materials and

Aesthetic Qualities of Cross Laminated Timber

DEFF Research Database (Denmark)

Bejder, Anne Kirkegaard

to its sustainable profile. In parallel to this, new production methods and further refined timber products have been developed. Among these are the engineered timber-based product Cross Laminated Timber (CLT) that show enhanced structural properties compared to unrefined timber. However, the question...... an undefined aesthetic potential that may innovate how we construct and perceive timber architecture, the overall aim of the thesis is to inquire into the architectural and aesthetic qualities of CLT. Through three chapters this thesis examines and discusses 1) the architectural qualities of CLT, 2......) the materiality of CLT, and 3) how one can deal with these qualitative aspects in the design process. This leads to: firstly, the development of an explicit model to help structuring the analysis and evaluation of the materiality of CLT, and secondly, a clarification and articulation of the aesthetic qualities...

Reliability Analysis of Structural Timber Systems

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Hoffmeyer, P.

2000-01-01

Structural systems like timber trussed rafters and roof elements made of timber can be expected to have some degree of redundancy and nonlinear/plastic behaviour when the loading consists of for example snow or imposed load. In this paper this system effect is modelled and the statistic...... of variation. In the paper a stochastic model is described for the strength of a single piece of timber taking into account the stochastic variation of the strength and stiffness with length. Also stochastic models for different types of loads are formulated. First, simple representative systems with different...... types of redundancy and non-linearity are considered. The statistical characteristics of the load bearing capacity are determined by reliability analysis. Next, more complex systems are considered modelling the mechanical behaviour of timber roof elements I stressed skin panels made of timber. Using...

CONTEMPORARY SLOVENIAN TIMBER ARCHITECTURE INTERNATIONAL RECOGNIZED

Directory of Open Access Journals (Sweden)

Manja Kitek Kuzman

2014-12-01

Full Text Available The book presents Slovenia' s contemporary timber architecture. Thanks to its abundant forests, Slovenia has preserved the tradition of wood construction. As much as 60% of its surface is covered by forests. Slovenia is also the third most forested country in Europe. The high share of forest-covered surface allows for a sustainable production of high-quality wood. In the past, wood was used primarily in the construction of farm buildings, but now timber architecture is used for everything from residences and office buildings to public buildings such as community centres and schools. Timber construction is becoming increasingly popular. Apart from larger companies taking this approach, a great number of wooden houses have sprung up, built either on personal initiative or with the support of carpenter workshops. Slovenian timber architecture has taken a new approach to environmental and energy-efficiency problems and received great international recognition. The book discusses over fifty projects built over a ten-year period, and includes descriptions, photographs, and plans. The projects include residential areas, administration, and office, as well as tourist, educational, and industrial buildings. Timber architecture is presented as an integral part of the Slovenian landscape. The monograph will be useful to designers and future experts in their planning of optimal timber buildings and will highlight the main benefits of using timber construction.

Projected US timber and primary forest product market impacts of climate change mitigation through timber set-asides

Science.gov (United States)

Prakash Nepal; Peter J. Ince; Kenneth E. Skog; Sun J. Chang

2013-01-01

Whereas climate change mitigation involving payments to forest landowners for accumulating carbon on their land may increase carbon stored in forests, it will also affect timber supply and prices. This study estimated the effect on US timber and primary forest product markets of hypothetical timber set-aside scenarios where US forest landowners would be paid to forego...

Control of borens in mine timbers

Energy Technology Data Exchange (ETDEWEB)

Yule, R A; Kennedy, M J

1978-07-01

The authors studied timber attack in Queensland mines by auger beetles and powder post beetles. When infested timber is taken into a mine the insects thrive at the temperatures (20 to 25 C) and relative humidities (70-90%) they encounter. Seven timber treatments were tested, and all were satisfactory except spraying with wood-preserving oil which contained a moderately effective insecticide.

General notes on ductility in timber structures

NARCIS (Netherlands)

Jorissen, A.J.M.; Fragiacomo, M.

2011-01-01

The paper discusses the implications of ductility in design of timber structures under static and dynamic loading including earthquakes. Timber is a material inherently brittle in bending and in tension, unless reinforced adequately. However connections between timber members can exhibit significant

IMPACTS OF TIMBER LEGALITY VERIFICATION SYSTEM IMPLEMENTATION ON THE SUSTAINABILITY OF TIMBER INDUSTRY AND PRIVATE FOREST

Directory of Open Access Journals (Sweden)

Elvida Yosefi Suryandari

2017-04-01

Full Text Available International market requires producers to proof the legality of their wood products to address the issues of illegal logging and illegal trade. Timber Legality Verification System (TLVS has been prepared by the Government of Indonesia that covering the upstream and downstream wood industries. This paper aims to evaluate gaps in the implementation of TLVS policy and its impact on the sustainability of timber industry. This study was using gap, descriptive and costs-structure analyzes. The study was conducted in three provinces, namely: DKI Jakarta, West Java and D.I. Yogyakarta. Research found that the effectiveness of the TLVS implementation was low due to relatively rapid policy changes. This situation became disincetive for investments in timber business. Private sector perceived that TLVS policy should be applied in the upstream of timber business. Hence, the industry and market in the downstream have not been fully support to this system. Furthermore, TLVS policy implementation was considered ineffective by timber industry as well as private forest managers, especially by micro industry and smallholder private forests. This situation threatened the sustainability of timber industry and private forests. Therefore, Institutions should be strengthened in order to improve the quality of human resources and the competitiveness of products.

Probabilistic Modeling of Timber Structures

DEFF Research Database (Denmark)

Köhler, J.D.; Sørensen, John Dalsgaard; Faber, Michael Havbro

2005-01-01

The present paper contains a proposal for the probabilistic modeling of timber material properties. It is produced in the context of the Probabilistic Model Code (PMC) of the Joint Committee on Structural Safety (JCSS) and of the COST action E24 'Reliability of Timber Structures'. The present...... proposal is based on discussions and comments from participants of the COST E24 action and the members of the JCSS. The paper contains a description of the basic reference properties for timber strength parameters and ultimate limit state equations for components and connections. The recommended...

36 CFR 223.32 - Timber sale operating plan.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Timber sale operating plan... SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER Timber Sale Contracts Contract Conditions and Provisions § 223.32 Timber sale operating plan. Sale contracts with a term of 2 years or more shall provide...

Long term contracts signed in Slovak timber business

International Nuclear Information System (INIS)

Haluza, I.

2005-01-01

The Slovak timber business is changing. The state-owned company, SR Forests, which cuts more then 50% of Slovak timber has signed long term agreements with major domestic timber processing companies - Smrecina, the Rettenmeier Tatra Timber saw mill in Liptovsky Mikulas and two paper mills - Mondi SCP Ruzomberok and Kappa Sturovo. In the past, only quarterly contracts were signed. Now, for the first time, two-year contracts have been signed that should help the timber processing industry and the forestry sector. The General Director of Lesy SR (SR Forests), Karol Vins, hopes for better sale prices. Company headquarters wants to maintain better control of prices than under the old system of timber sales by its branches. In the opinion of the General Director of the Forestry Section at the Ministry of Agriculture, long term contracts will guarantee a stable delivery of timber to processing companies, giving investors in new production capacity a better position in negotiations with banks regarding financing. According to K. Vins, long term contracts have so far only been negotiated with major timber processing companies which are mostly controlled by foreign capital and therefore have good payment discipline. The Association of the Timber Processing Industry is unhappy regarding developments and Lesy SR has not invited domestic companies to these negotiations

Rent-seeking and timber rights allocation in Ghana

DEFF Research Database (Denmark)

Carlsen, Kirsten; Hansen, Christian Pilegaard

2014-01-01

This paper describes types, processes and importance of rent-seeking in the allocation of timber rights in Ghana. It is based on an analysis of 30 interviews with large-, medium- and small-scale timber firms, as well as government officials and timber industry organizations in Ghana. The paper...... documents that timber rights allocation is associated with both bureaucratic and political corruption. The latter comes in two forms. First, the findings suggest that well-established relationships exist between politicians and senior bureaucrats on the one side and large-scale timber firms on the other...

Advancing Coordination Between DRM and CCA in Integrated Flood Risk Management

DEFF Research Database (Denmark)

Flood hazards in coastal regions induce risks toward lives, property, economy and the environment. In need of sustainable and holistic actions to reduce risks, these should include innovative Disaster Risk Management (DRM) and Climate Change Adaptation (CCA) measures. While differing on important...

characterisation and grading of two selected timber species grown

African Journals Online (AJOL)

HOD

Structural timber is the timber used in framing and load bearing ... The main challenge in design with timber as structural member is to .... is the classification of timber based on particular ..... Azadirachta indica leaf extract on serum lipid profile.

Timber resource statistics for eastern Washington, 1995.

Science.gov (United States)

Neil McKay; Patricia M. Bassett; Colin D. MacLean

1995-01-01

This report summarizes a 1990-91 timber resource inventory of Washington east of the crest of the Cascade Range. The inventory was conducted on all private and public lands except National Forests. Timber resource statistics from National Forest inventories also are presented. Detailed tables provide estimates of forest area, timber volume, growth, mortality, and...

Timber floors strengthened with concrete

NARCIS (Netherlands)

Blass, H.J.; Linden, M.L.R. van der; Schlager, M.

1998-01-01

Timber-concrete composite (tcc) beams may be used for the renovation of old timber floors. Although these systems are not new (Pokulka, 1997) and form a simple and practical solution, they are not widely adopted. One of the reasons for this is the Jack of uniform design rules. In this research

Timber-concrete composite floor systems

NARCIS (Netherlands)

Linden, M.L.R. van der; Blass, H.J.

1996-01-01

Timber-concrete composite (tcc) beams may be used for the renovation of old timber floors. Although these systems are a simple and practical solution, they are not widely adopted. One of the reasons for this is the lack of uniform design mies. In this research programme shear tests on four different

A PROBABILISTIC EXPOSURE ASSESSMENT FOR CHILDREN WHO CONTACT CCA-TREATED PLAYSETS AND DECKS USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL FOR THE WOOD PRESERVATIVE EXPOSURE SCENARIO

Science.gov (United States)

The U.S. Environmental Protection Agency has conducted a probabilistic exposure and dose assessment on the arsenic (As) and chromium (Cr) components of Chromated Copper Arsenate (CCA) using the Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS-Wood...

Structural Reliability of the Nigerian Grown Abura Timber Bridge ...

African Journals Online (AJOL)

Structural reliability analysis was carried out on the Nigerian grown Abura timber, to ascertain its structural performance as timber bridge beams. Samples of the Nigerian grown Abura timber were bought from timber market, seasoned naturally and their structural/strength properties were determined at a moisture content of ...

Timber resource statistics for southwest Washington.

Science.gov (United States)

Patricia M. Bassett; Daniel D. Oswald

1981-01-01

This report summarizes a 1978 timber-resource inventory of six counties in southwest Washington: Clark, Cowlitz, Lewis, Pacific, Skamania, and Wahkiakum. Detailed tables of forest area, timber volume, growth, mortality, and harvest are presented.

Methodology for safety evaluation of existing timber elements

OpenAIRE

Sousa, Hélder S.

2013-01-01

Tese de doutoramento em Engenharia Civil The past decades have seen a renewed interest in timber research related topics. As instance, timber engineering is not only confined to the design of new construction with innovative wood based products, but also an increasing awareness for the preservation of existing timber structures is visible in nowadays society. Therefore, arises the need for a better understanding of timber performance as a construction material aiming at a bette...

Timber frame walls

DEFF Research Database (Denmark)

Hansen, Ernst Jan de Place; Brandt, Erik

2010-01-01

A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber framed walls. Timber frame walls with no cavity are a logical alternative as they are slimmer and less expensive to produce and besides the risk of a two-sided fire behind the cladding....... It was found that the specific damages made to the vapour barrier as part of the test did not have any provable effect on the moisture content. In general elements with an intact vapour barrier did not show a critical moisture content at the wind barrier after four years of exposure....

W342F Mutation in CCaMK Enhances Its Affinity to Calmodulin But Compromises Its Role in Supporting Root Nodule Symbiosis in Medicago truncatula

Directory of Open Access Journals (Sweden)

Edgard Jauregui

2017-11-01

Full Text Available The calcium/calmodulin-dependent protein kinase (CCaMK is regulated by free Ca2+ and Ca2+-loaded calmodulin. This dual binding is believed to be involved in its regulation and associated physiological functions, although direct experimental evidence for this is lacking. Here we document that site-directed mutations in the calmodulin-binding domain of CCaMK alters its binding capacity to calmodulin, providing an effective approach to study how calmodulin regulates CCaMK in terms of kinase activity and regulation of rhizobial symbiosis in Medicago truncatula. We observed that mutating the tryptophan at position 342 to phenylalanine (W342F markedly increased the calmodulin-binding capability of the mutant. The mutant CCaMK underwent autophosphorylation and catalyzed substrate phosphorylation in the absence of calcium and calmodulin. When the mutant W342F was expressed in ccamk-1 roots, the transgenic roots exhibited an altered nodulation phenotype. These results indicate that altering the calmodulin-binding domain of CCaMK could generate a constitutively activated kinase with a negative role in the physiological function of CCaMK.

Timber resource statistics for eastern Washington.

Science.gov (United States)

Patricia M. Bassett; Daniel D. Oswald

1983-01-01

This report summarizes a 1980 timber resource inventory of the 16 forested counties in Washington east of the crest of the Cascade Range. Detailed tables of forest area, timber volume, growth, mortality, and harvest are presented.

A General Construction of IND-CCA2 Secure Public Key Encryption

DEFF Research Database (Denmark)

Kiltz, Eike; Malone-Lee, John

2003-01-01

We propose a general construction for public key encryption schemes that are IND-CCA2 secure in the random oracle model. We show that the scheme proposed in [1, 2] fits our general framework and moreover that our method of analysis leads to a more efficient security reduction....

Nailed timber beams with I composed section

Directory of Open Access Journals (Sweden)

Jorge Luís Nunes de Góes

2003-01-01

Full Text Available The employment of built-up timber beams, made of commercial dimensions pieces, is becoming increasingly important in timber structures in Brazil, mainly due to the ever-growing scarcity of timber elements in larger sizes. The built-up system has vast application, from beams for residential buildings to girders for small bridges. The objective of this work is the theoretical and experimental study of nailed timber beams with composed cross section I. The design procedure of EUROCODE 5/93 and NBR 7190/97 are shown and evaluated, as well as the theory about the subject matter. The experimental evaluation of the theoretical models was made by means of bending tests in prototypes of built-up timber beams. The obtained results shows that the EUROCODE 5/93 procedure is the most indicated for evaluating effective bending stiffness, normal and shear stresses as well as the load on fasteners.

The Materiality of Novel Timber Architecture

DEFF Research Database (Denmark)

Bejder, Anne Kirkegaard; Kirkegaard, Poul Henning; Wraber, Ida Kristina

2016-01-01

In recent years, wood as a building material has gained renewed focus and, in parallel, new production methods and further refined timber products have been developed. Many of these novel timber building materials have gained significantly enhanced technical qualities, and the question is whether...... this is at the expense of wood’s sensuous and poetic qualities. The proposed method to deal with these questions is to develop a discursive model that can clarify aspects essential for analyzing and discussing the materiality of timber in its contemporary engineered forms. Firstly, this paper presents a theoretical...

Determination of the distribution of copper and chromium in partly remediated CCA-treated pine wood using SEM and EDX analyses

DEFF Research Database (Denmark)

Christensen, Iben Vernegren; Ottosen, Lisbeth M.; Melcher, Eckhard

2005-01-01

. After soaking, a small amount of Cu and Cr was still present in the cell walls but larger particles were now found on wall surfaces. Most effective removal of Cu was obtained after soaking in phosphoric and oxalic acid followed by EDR; here numerous rice grain-shaped particles were observed containing...... large amounts of Cu and no Cr. Cr was most effectively removed after soaking in oxalic acid and subsequent EDR treatment or dual soaking in phosphoric acid and oxalic acid with and without subsequent EDR.......Soaking in different acids and electrodialytic remediation (EDR) were applied for removing copper and chromium from freshly Chromated Copper Arsenate (CCA) impregnated EN 113 pine wood samples. After remedial treatments, AAS analyses revealed that the concentration of copper (Cu) and chromium (Cr...

Reliability and Robustness Evaluation of Timber Structures

DEFF Research Database (Denmark)

Cizmar, Dean; Sørensen, John Dalsgaard; Kirkegaard, Poul Henning

In the last few decades there have been intensely research concerning reliability of timber structures. This is primarily because there is an increased focus on society on sustainability and environmental aspects. Modern timber as a building material is also being competitive compared to concrete...... and steel. However, reliability models applied to timber were always related to individual components but not the systems. as any real structure is a complex system, system behaviour must be of a particular interest. In the chapter 1 of this document an overview of stochastic models for strength and loads...... (deterministic, probabilistic and risk based approaches) of the robustness are given. Chapter 3 deals more detailed with the robustness of timber structures....

Graphic-Card Cluster for Astrophysics (GraCCA) -- Performance Tests

OpenAIRE

Schive, Hsi-Yu; Chien, Chia-Hung; Wong, Shing-Kwong; Tsai, Yu-Chih; Chiueh, Tzihong

2007-01-01

In this paper, we describe the architecture and performance of the GraCCA system, a Graphic-Card Cluster for Astrophysics simulations. It consists of 16 nodes, with each node equipped with 2 modern graphic cards, the NVIDIA GeForce 8800 GTX. This computing cluster provides a theoretical performance of 16.2 TFLOPS. To demonstrate its performance in astrophysics computation, we have implemented a parallel direct N-body simulation program with shared time-step algorithm in this system. Our syste...

Reinforcement and recovery of timber structures

Directory of Open Access Journals (Sweden)

Antonio Alves Dias

2006-02-01

Full Text Available Preservation of timber structures is a reason for constant concern because their deterioration often involves compromising the historical patrimony, besides endangering the safety of the structure, and consequently, of their users. Many are the examples of churches, residences or other constructions where this manifestation is a fact. The technique of reinforcing structurally endangered pieces with the addition of natural or synthetic fibers, is an alternative that has been researched. In the group of synthetic fibers, fiberglass, carbon and aramid ones are included. On the other hand, it has been frequent in the restoration of old buildings, especially in Europe, the employment of materials that were not available in the past, aiming to achieve structural, acoustic and aesthetic benefits. On an existing timber structure floor, a concrete slab has been carried out, with an appropriate connection system among the parts, constituting the composite timber-concrete structures. This alternative has been considered as extraordinarily viable, because it gathers a series of convenience related with the durability and it presents better mechanic performance than conventional timber structures. In this work, the state-of-the-art of the use of fibers as structural reinforcement and of the timber-concrete composite structures, is presented.

Value of timber continues to increase

International Nuclear Information System (INIS)

Haluza, I.

2007-01-01

The state owned company, Lesy SR (state forests) enjoys great power in the timber industry. It can influence which timber processing companies in Slovakia will be successful and which will not have easy access to the raw material. It manages half of the forests in Slovakia. It is the only seller of timber in this country. Four years ago, the former cabinet appointed banker, Karol Vins, as the director of the company. And he started making changes. He centralized the timber business and thousands of people left the company. The goal was clear -to increase quality and efficiency. The economic performance of the company improved. The company has finally managed to post a profit. Last year, the government changed and so has the director of the company The former banker was replaced by a new head from a forestry research background, Jozef Mindas. He approves of some of the changes introduced by his predecessor and plans to continue implementing them, although there also those he would like to change. The new manager is not concerned regarding the big change from research where he used to work in the past to director of a big company and rejects the allegation that he was nominated by HZDS. I was approached as an expert and I won a tender. I have never been a member of a political party, he stated. He appreciates that his predecessor managed to revitalize the company, which was assisted by the positive effect of out-sourcing. But on the other hand, during transformation forests were not divided up correctly. The division into units did not always take into account the specific requirements of forestry, i.e. some employees in forest units have too much work and some, working in another forest unit, less. We have to make sure that the workload is approximately at the same level everywhere. He is aware of the fact that Lesy SR, which controls two thirds of the timber market, effectively decides which factory will succeed and which one will not. But he adds that Lesy SR do

Effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood

International Nuclear Information System (INIS)

Cao Xinde; Ma, Lena Q.

2004-01-01

Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects of soil amendments on plant As accumulation. Carrot (Daucus carota L.) and lettuce (Lactuca sativa L.) were grown for ten weeks in the soil with or without compost and phosphate amendments. As expected, elevated As concentrations were observed in the pole soil (43 mg kg -1 ) and in the fence soil (27 mg kg -1 ), resulting in enhanced As accumulation of 44 mg kg -1 in carrot and 32 mg kg -1 in lettuce. Addition of phosphate to soils increased As accumulation by 4.56-9.3 times for carrot and 2.45-10.1 for lettuce due to increased soil water-soluble As via replacement of arsenate by phosphate in soil. However, biosolid compost application significantly reduced plant As uptake by 79-86%, relative to the untreated soils. This suppression is possibly because of As adsorbed by biosolid organic mater, which reduced As phytoavailability. Fractionation analysis showed that biosolid decreased As in soil water-soluble, exchangeable, and carbonate fraction by 45%, whereas phosphate increased it up to 2.61 times, compared to the untreated soils. Our results indicate that growing vegetables in soils near CCA-treated wood may pose a risk of As exposure for humans. Compost amendment can reduce such a risk by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils. Caution should be taken for phosphate application since it enhances As accumulation. - Capsule: Compost amendment can reduce As exposure risk for humans by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils

Effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood

Energy Technology Data Exchange (ETDEWEB)

Cao Xinde [Soil and Water Science Department, University of Florida, Gainesville, FL (United States)]. E-mail: xcao@stevens.edu; Ma, Lena Q. [Soil and Water Science Department, University of Florida, Gainesville, FL (United States)

2004-12-01

Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects of soil amendments on plant As accumulation. Carrot (Daucus carota L.) and lettuce (Lactuca sativa L.) were grown for ten weeks in the soil with or without compost and phosphate amendments. As expected, elevated As concentrations were observed in the pole soil (43 mg kg{sup -1}) and in the fence soil (27 mg kg{sup -1}), resulting in enhanced As accumulation of 44 mg kg{sup -1} in carrot and 32 mg kg{sup -1} in lettuce. Addition of phosphate to soils increased As accumulation by 4.56-9.3 times for carrot and 2.45-10.1 for lettuce due to increased soil water-soluble As via replacement of arsenate by phosphate in soil. However, biosolid compost application significantly reduced plant As uptake by 79-86%, relative to the untreated soils. This suppression is possibly because of As adsorbed by biosolid organic mater, which reduced As phytoavailability. Fractionation analysis showed that biosolid decreased As in soil water-soluble, exchangeable, and carbonate fraction by 45%, whereas phosphate increased it up to 2.61 times, compared to the untreated soils. Our results indicate that growing vegetables in soils near CCA-treated wood may pose a risk of As exposure for humans. Compost amendment can reduce such a risk by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils. Caution should be taken for phosphate application since it enhances As accumulation. - Capsule: Compost amendment can reduce As exposure risk for humans by reducing As accumulation by vegetables and can be an important strategy for remediating CCA

Evaluation of circulating cathodic antigen (CCA) strip for diagnosis of urinary schistosomiasis in Hassoba school children, Afar, Ethiopia

OpenAIRE

Ayele B.; Erko B.; Legesse M.; Hailu A.; Medhin G.

2008-01-01

A total of 206 urine samples collected from Hassoba Elementary schoolchildren, Afar, Ethiopia, a low Schistosoma haematobium endemic setting, was diagnosed to evaluate the performance of CCA strip using double references, urine filtration technique and urinalysis dipstick (Combur 10 Test®) that detect schistosome eggs and blood in urine, respectively. The former was used as a gold standard reference method. Sensitivity, specificity, positive and negative predictive values for the CCA were 52%...

Timber resource of Missouri's Prairie, 1972.

Science.gov (United States)

Jerold T. Hahn; Alexander Vasilevsky

1975-01-01

The third timber inventory of Missouri's Prairie Forest Survey Unit shows substantial declines in both growing-stock and sawtimber volumes between 1959 and 1972. Commercial forest area declined by one-fifth. Presents highlights and statistics on forest area and timber volume, growth, mortality, ownership, and use in 1972.

Timber Price Dynamics Following a Natural Catastrophe

OpenAIRE

Jeffrey P. Prestemon; Thomas P. Holmes

2000-01-01

Catastrophic shocks to existing stocks of a renewable resource can cause long-run price shifts. With timber, these long-run price shifts may be accompanied by a short-run price drop due to salvage. Hurricane Hugo damaged 20% of southern pine timber in the South Carolina Coastal Plain in 1989. To estimate the short- and long-run effects of the hurricane on the prices of timber stocks, we estimated an intervention model of the residuals of cointegration of South Carolina sawtimber and pulpwood ...

Modified traditional Japanese timber joint system with retrofitting abilities

NARCIS (Netherlands)

Shiratori, T.; Komatsu, K.; Leijten, A.J.M.

2008-01-01

Embedment is a key feature of timber joints envisioned as the ultimate solution in avoiding the devastating full collapse of timber structures in seismic countries. The Japanese traditional timber post-and-beam structural system utilizes moment-resisting joints based on embedment. Despite the

Timber resource statistics for western Washington.

Science.gov (United States)

Coffin D. MacLean; Patricia M. Bassett; Glenn. Yeary

1992-01-01

This report summarizes a 1988-90 timber resource inventory of 19 counties in western Washington: Clallam, Clark, Cowlitz, Grays Harbor, Island, Jefferson, King, Kitsap, Lewis, Mason, Pacific, Pierce, San Juan, Skagit, Skamania, Snohomish, Thurston, Wahkiakum, and Whatcom. Detailed tables of forest area, timber volume, growth, mortality, and harvest are presented.

On several parameters of mechanized timbering for working faces

Energy Technology Data Exchange (ETDEWEB)

Klorik' yan, S Kh

1979-08-01

Opinion is expressed that the two basic parameters characterizing mechanical timbers, the specific force in ton-forces per square meter of the supported roof surface over the working area and the one-meter length of installed timbering, do not permit selection of the optimum type of timber for a roof of the corresponding class. Experience has demonstrated that the most precise parameter is specific strength of the timber in ton-forces per meter and the determined ratio of the strength of all posts in a section to spacing of the section along the longwall. Also an operating width not exceeding 0.4 meter should serve as a criterion for using timbers on unstable hanging walls. (In Russian)

Sumoylation of the Plant Clock Transcription Factor CCA1 Suppresses DNA Binding

NARCIS (Netherlands)

Hansen, L.L.; Imrie, L.; Le Bihan, T.; van den Burg, H.A.; van Ooijen, G.

2017-01-01

In plants, the circadian clock regulates the expression of one-third of all transcripts and is crucial to virtually every aspect of metabolism and growth. We now establish sumoylation, a posttranslational protein modification, as a novel regulator of the key clock protein CCA1 in the model plant

Safety of timber : An analysis of quality control options

NARCIS (Netherlands)

Kovryga, A.; Stapel, P.; Van de Kuilen, J.W.G.

2014-01-01

The quality assurance of timber properties is important for the safety of timber structures. In the current study, the quality control options of timber are analysed under the prism of the different growth regions. Therefore, these options - machine and output control - are simulated in accordance

Online Sorting of Wood Treated with Chromated Copper Arsenate Using Laser Induced Breakdown Spectroscopy

National Research Council Canada - National Science Library

Moskal, Thomas

2001-01-01

.... While CCA treated wood has several benefits, with perhaps the most important being the saving of an estimated 225 million trees annually due to its longer service life, there are growing concerns...

Markets, Government Policy, and China’s Timber Supply

Science.gov (United States)

Han Zhang; Joseph Buongiorno

2012-01-01

China’s domestic demand and exports of wood products are rising rapidly compared to domestic supply. The determinants of timber supply in China were investigated with panel data from 25 provinces from 1999 to 2009. The results indicated that China’s timber supply had responded to both market forces, reflected by timber prices largely determined by world demand and...

FRP reinforcement of timber structures

OpenAIRE

Schober, Kay-Uwe; Harte, Annette M.; Kliger, Robert; Jockwer, Robert; Xu, Qingfeng; Chen, Jian-Fei

2015-01-01

Timber engineering has advanced over recent decades to offer an alternative to traditional materials and methods. The bonding of fibre reinforced plastics (FRP) with adhesives to timber structures for repair and strengthening has many advantages. However, the lack of established design rules has strongly restrained the use of FRP strengthening in many situations, where these could be a preferable option to most traditional techniques. A significant body of research has been carried out in rec...

Moisture Content Monitoring of a Timber Footbridge

Directory of Open Access Journals (Sweden)

Niclas Björngrim

2016-03-01

Full Text Available Construction of modern timber bridges has greatly increased during the last 20 years in Sweden. Wood as a construction material has several advantageous properties, e.g., it is renewable, sustainable, and aesthetically pleasing, but it is also susceptible to deterioration. To protect wood from deterioration and ensure the service life, the wood is either treated or somehow covered. This work evaluates a technology to monitor the moisture content in wood constructions. Monitoring the moisture content is important both to verify the constructive protection and for finding areas with elevated levels of moisture which might lead to a microbiological attack of the wood. In this work, a timber bridge was studied. The structure was equipped with six wireless sensors that measured the moisture content of the wood and the relative humidity every hour. Data for 744 days of the bridge are presented in this paper. Results show that the technology used to monitor the bridge generally works; however, there were issues due to communication problems and malfunction of sensors. This technology is promising for monitoring the state of wood constructions, but a more reliable sensor technology is warranted continuous remote monitoring of wood bridges over long periods of time.

36 CFR 223.62 - Timber purchaser road construction credit.

Science.gov (United States)

2010-07-01

... § 223.62 Timber purchaser road construction credit. Appraisal may also establish stumpage value as if... timber is appraised and sold on such basis, purchaser credit for road construction, not to exceed the estimated construction cost of such roads or other developments specified in the timber sale contract, shall...

Timber tracking

DEFF Research Database (Denmark)

Düdder, Boris; Ross, Omry

2017-01-01

Managing and verifying forest products in a value chain is often reliant on easily manipulated document or digital tracking methods - Chain of Custody Systems. We aim to create a new means of tracking timber by developing a tamper proof digital system based on Blockchain technology. Blockchain...

Ranking independent timber investments by alternative investment criteria

Science.gov (United States)

Thomas J. Mills; Gary E. Dixon

1982-01-01

A sample of 231 independent timber investments were ranked by internal rate of return, present net worth per acre and the benefit cost ratio—the last two discounted by 3, 6.4. 7.5. and 10 percent—to determine if the different criteria had a practical influence on timber investment ranking. The samples in this study were drawn from a group of timber investments...

Aggregate Timber Supply: From the Forest to the Market

Science.gov (United States)

David N. Wear; Subhrendu K. Pattanayak

2003-01-01

Timber supply modeling is a means of formalizing the production behavior of heterogeneous landowners managing a wide variety of forest types and vintages within a region. The critical challenge of timber supply modeling is constructing theoretically valid and empirically practical aggregate descriptions of harvest behavior. Understanding timber supply is essential for...

Enviromentally Sound Timber Extracting Techniques for Small Tree Harvesting

Science.gov (United States)

Lihai Wang

1999-01-01

Due to large area disturbed and great deal of energy cost during-its operations, introducing or applying the appropriate timber extracting techniques could significantly reduce the impact of timber extraction operations to forest environment while pursuing the reasonable operation costs. Four environmentally sound timber extraction techniques for small tree harvesting...

Collapse Analysis of Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2008-01-01

of Structures and a probabilistic modelling of the timber material proposed in the Probabilistic Model Code (PMC) of the Joint Committee on Structural Safety (JCSS). Due to the framework in the Danish Code the timber structure has to be evaluated with respect to the following criteria where at least one shall...... to criteria a) and b) the timber frame structure has one column with a reliability index a bit lower than an assumed target level. By removal three columns one by one no significant extensive failure of the entire structure or significant parts of it are obtained. Therefore the structure can be considered......A probabilistic based collapse analysis has been performed for a glulam frame structure supporting the roof over the main court in a Norwegian sports centre. The robustness analysis is based on the framework for robustness analysis introduced in the Danish Code of Practice for the Safety...

Section of mechanized timbering of an installation layer

Energy Technology Data Exchange (ETDEWEB)

Gur' yev, D K; Tomashevskiy, L P; Vorotnyak, M V

1980-07-28

A section of mechanized timbering of an installation layer is suggested which includes roof timber, base with cantilever, hydrostand, safety guard which consists of a lower and upper shield, where the lower shield in the lower part has a roll whose upper part is hinged to the cantilever base, and the upper shield is hinged to the roof timber. Its lower part is connected by a linkage to the cantilever of the base. There is also a correcting device, tie rod and holder with rolled material. In order to guarantee stability of the timbering section during work on thick beds and adaptability of the roof timber to the roofing of the bed, the connection between the cantilever and the lower part of the upper shield is made from a longitudinal slit on the cantilever and slide bar placed in it. It is attached by a pin to the lower part of the upper shield. In this case the tie bar is hinged to the linkage and by means of the slide bar to the roof timber, while the correcting device is made of an extension-type support with level which contacts with the wedge and the tightening element installed on the cantilever of the base.

Timber Management Opportunities for Nebraska 1983-1992

Science.gov (United States)

W. Brad Smith; Tom D. Wardle

1984-01-01

Reviews opportunities for treatment of timber stands in Nebraska for the decade 1983 - 1992. Under the assumptions and management guides specified, 52 percent of Nebraska''s commercial forest land would benefit from timber harvest or some other form of treatment during the decade.

Tall timber building technologies in The Netherlands

NARCIS (Netherlands)

Jorissen, A.J.M.; Leijten, A.J.M.

2008-01-01

In the last few decades, structural timber for residential buildings has lost popularity because of problems related to floor vibrations, acoustics and fire resistance. In recent years, however, solutions to these problems have been developed and timber-framed housing is becoming increasingly

Probabilistic Modelling of Timber Material Properties

DEFF Research Database (Denmark)

Nielsen, Michael Havbro Faber; Köhler, Jochen; Sørensen, John Dalsgaard

2001-01-01

The probabilistic modeling of timber material characteristics is considered with special emphasis to the modeling of the effect of different quality control and selection procedures used as means for grading of timber in the production line. It is shown how statistical models may be established...... on the basis of the same type of information which is normally collected as a part of the quality control procedures and furthermore, how the efficiency of different control procedures may be compared. The tail behavior of the probability distributions of timber material characteristics play an important role...... such that they may readily be applied in structural reliability analysis and the format appears to be appropriate for codification purposes of quality control and selection for grading procedures...

Operability and location of Wisconsin's timber resource.

Science.gov (United States)

Jerold T. Hahn; Mark H. Hansen

1989-01-01

Data collected during the 1983 Wisconsin Statewide forest inventory were used to examine operability of the timber resource based on seven operability components. Operability is the ease or difficulty of managing or harvesting timber because of physical conditions in the stand or on the site.

Operability and location of Michigan's timber resource.

Science.gov (United States)

Mark H. Hansen; Jerold T. Hahn

1987-01-01

Operability is the ease or difficulty of managing or harvesting timber because of physical conditions in the stand or on the site. Data collected during the 1980 Michigan statewide forest inventory were used to examine operability of the timber resource based on seven operability components.

Recommendations for sustainable development of non-timber forest products

Science.gov (United States)

Gina H. Mohammed

2001-01-01

Non-timber forest products--or NTFPs--are considered here to be botanical products harvested or originating from forest-based species, but excluding primary timber products, industrial boards and composites, and paper products. A recent study of non-timber forest products in Ontario, Canada, identified at least 50 types of NTFPs and hundreds of specific products used...

Pilot-scale investigation of the robustness and efficiency of a copper-based treated wood wastes recycling process

Energy Technology Data Exchange (ETDEWEB)

Coudert, Lucie [INRS-ETE (Canada); Blais, Jean-François, E-mail: blaisjf@ete.inrs.ca [INRS-ETE (Canada); Mercier, Guy [INRS-ETE (Canada); Cooper, Paul [University of Toronto (Canada); Gastonguay, Louis [IREQ (Canada); Morris, Paul [FPInnovations (Canada); Janin, Amélie; Reynier, Nicolas [INRS-ETE (Canada)

2013-10-15

Highlights: • A leaching process was studied for metals removal from CCA-treated wood wastes. • This decontamination process was studied at pilot scale (130-L reactor). • Removals up to 98% of As, 88% of Cr, and 96% of Cu were obtained from wood wastes. • The produced leachates can be treated by chemical precipitation. -- Abstract: The disposal of metal-bearing treated wood wastes is becoming an environmental challenge. An efficient recycling process based on sulfuric acid leaching has been developed to remove metals from copper-based treated wood chips (0 < x < 12 mm). The present study explored the performance and the robustness of this technology in removing metals from copper-based treated wood wastes at a pilot plant scale (130-L reactor tank). After 3× 2 h leaching steps followed by 3× 7 min rinsing steps, up to 97.5% of As, 87.9% of Cr, and 96.1% of Cu were removed from CCA-treated wood wastes with different initial metal loading (>7.3 kg m{sup −3}) and more than 94.5% of Cu was removed from ACQ-, CA- and MCQ-treated wood. The treatment of effluents by precipitation–coagulation was highly efficient; allowing removals more than 93% for the As, Cr, and Cu contained in the effluent. The economic analysis included operating costs, indirect costs and revenues related to remediated wood sales. The economic analysis concluded that CCA-treated wood wastes remediation can lead to a benefit of 53.7 US$ t{sup −1} or a cost of 35.5 US$ t{sup −1} and that ACQ-, CA- and MCQ-treated wood wastes recycling led to benefits ranging from 9.3 to 21.2 US$ t{sup −1}.

Rainfall prediction of Cimanuk watershed regions with canonical correlation analysis (CCA)

Science.gov (United States)

Rustiana, Shailla; Nurani Ruchjana, Budi; Setiawan Abdullah, Atje; Hermawan, Eddy; Berliana Sipayung, Sinta; Gede Nyoman Mindra Jaya, I.; Krismianto

2017-10-01

Rainfall prediction in Indonesia is very influential on various development sectors, such as agriculture, fisheries, water resources, industry, and other sectors. The inaccurate predictions can lead to negative effects. Cimanuk watershed is one of the main pillar of water resources in West Java. This watersheds divided into three parts, which is a headwater of Cimanuk sub-watershed, Middle of Cimanuk sub-watershed and downstream of Cimanuk sub- watershed. The flow of this watershed will flow through the Jatigede reservoir and will supply water to the north-coast area in the next few years. So, the reliable model of rainfall prediction is very needed in this watershed. Rainfall prediction conducted with Canonical Correlation Analysis (CCA) method using Climate Predictability Tool (CPT) software. The prediction is every 3months on 2016 (after January) based on Climate Hazards group Infrared Precipitation with Stations (CHIRPS) data over West Java. Predictors used in CPT were the monthly data index of Nino3.4, Dipole Mode (DMI), and Monsoon Index (AUSMI-ISMI-WNPMI-WYMI) with initial condition January. The initial condition is chosen by the last data update. While, the predictant were monthly rainfall data CHIRPS region of West Java. The results of prediction rainfall showed by skill map from Pearson Correlation. High correlation of skill map are on MAM (Mar-Apr-May), AMJ (Apr-May-Jun), and JJA (Jun-Jul-Aug) which means the model is reliable to forecast rainfall distribution over Cimanuk watersheds region (over West Java) on those seasons. CCA score over those season prediction mostly over 0.7. The accuracy of the model CPT also indicated by the Relative Operating Characteristic (ROC) curve of the results of Pearson correlation 3 representative point of sub-watershed (Sumedang, Majalengka, and Cirebon), were mostly located in the top line of non-skill, and evidenced by the same of rainfall patterns between observation and forecast. So, the model of CPT with CCA method

Selection of Nepalese Timber for Small Wind Turbine Blade Construction

DEFF Research Database (Denmark)

Sinha, R.; Acharya, Parash; Freere, Peter

2010-01-01

, weathering effect on coatings, price, growth and availability of the timber. Mechanical properties such as Young's modulus of elasticity, breaking strength, breaking strain and Brinell's hardness of selected Nepalese timbers are presented. The effects of weathering on timbers without coating...

The Level of Utilization of Secondary Timber Species among Furniture Producers

Directory of Open Access Journals (Sweden)

Charles Antwi-Boasiako

2016-06-01

Full Text Available Background and Purpose: Inadequate supply of wood raw material is one of the major obstacles for the global furniture industry’s growth. Several secondary timbers/Lesser-Utilized-Species (LUS that could substitute the scarce traditional timbers for furniture production exist in tropical forests. However, the industry continuously faces persistent timber shortages. The extent to which manufacturers utilize LUS as alternatives is unclear, which this study sought to ascertain. Materials and Methods: Data were collected from 300 Timber Firms from Ghana primarily through questionnaires using the stratified random sampling technique. Results: Continuous decline and non-availability of preferred traditional timbers and competition from imported furniture were the main challenges confronting the furniture industry. Data obtained indicated that most manufacturers (85% hardly use any LUS; 44% of these mentioned lack of information on their properties and prospective uses and 32% attributed it to non-availability on the domestic timber markets. However, 22% of these producers rely on traditionally ‘well-known’ timbers (e.g. mixed red wood, Guarea cedrata and Tectona grandis owing to their strength properties, 20% due to their strength and durability and 14% because of their strength and aesthetic properties. Many LUS (with prospects for furniture-making available in great quantities in many tropical forests could substitute the over-dependent timbers. However, information on their properties and uses are hardly available to local producers, which affects their popularity among timber suppliers and manufacturers. Conclusion: To improve on the level of utilization of secondary timbers, wood workers must be supplied with comprehensive information about their properties and economic values. This will contribute to reducing pressure on the primary timbers, ensuring consistent supply of timber and keeping the sector operational.

California’s forest products industry and timber harvest, 2006

Science.gov (United States)

Todd A. Morgan; Jason P. Brandt; Kathleen E. Songster; Charles E. Keegan; Glenn A. Christensen

2012-01-01

This report traces the flow of California’s 2006 timber harvest through the primary wood products industry (i.e., firms that process timber into manufactured products such as lumber, as well as facilities such as pulp mills and particleboard plants, which use the wood fiber or mill residue directly from timber processors) and provides a description of the structure,...

Case Studies on Timber Defects of Selected Traditional Houses in Malacca

Directory of Open Access Journals (Sweden)

Nor Haniza Ishak

2007-12-01

Full Text Available The effect of adverse environmental conditions on building materials and the extent of damage caused depends on both the materials used and the environmental conditions. Although timber is a diminishing resource, it is still widely used in today's construction. In Malaysia, timber is one of the main components of many historic buildings. Appropriate maintenance of such buildings requires an understanding of timber defects and its related problems. Timber defects are classified into two major groups: non-biological and biological deteriorations. Non-biological deterioration consists of physical decay, excessive moisture content, dimensional instability and chemical deterioration. These defects are mainly caused by the timber in service being subjected to environmental exposure. The most common and destructive timber biological deteriorations are those due to dry rot, we t rot as well as insect attacks . A study based on seven selected houses was conducted to identify the most common building defects, specifically on timber components amongst traditional Malay houses in Malacca, Malaysia, A building condition survey was carried out to determine the effect of the environment towards timber buildings and their main components. Data collected were based on the investigation and visual observation of the selected case studies. Findings of this research will serve as an indicator towards maintaining the buildings' timber components in good condition in order that the buildings' life span could be extended and primarily to conserve the valuable traditional timber houses in a historical city.

Robustness Issues for Design of Innovative Timber Structures

DEFF Research Database (Denmark)

Hald, Frederik; Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2013-01-01

Robustness of structural systems has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious conse-quences in case of failure. The present paper summaries issues with respect to robustness of timber structures. Two different...... large span timber structures are analyzed and based on these analyses the paper presents guidelines for the future development of innovative timber struc-tures which are robust with respect to design and execution errors, unforeseen degradation and other potential hazards....

Industrialized timber structures.

Science.gov (United States)

1974-01-01

It was recently learned that a number of innovations in structural timber components are available to the construction industry, but that they were largely unknown to bridge designers. The purpose of this study was to develop for the Department a fea...

Timber resource statistics for the Olympic Peninsula, Washington.

Science.gov (United States)

Patricia M. Bassett; Daniel D. Oswald

1961-01-01

This report summarizes a 1978-79 timber resource inventory of five counties in the Olympic Peninsula of Washington: Clallam, Grays Harbor, Jefferson, Mason, and Thurston. Detailed tables of forest area, timber volume, growth, mortality, and harvest are presented.

Procurement of timber for the Finnish forest industries

International Nuclear Information System (INIS)

Hakkila, P.

1995-01-01

The procurement of timber to the forest industries in the Nordic countries is based on the log-length or shortwood system, and employs load-carrying forwarders and chainsaw of single-grip harvesters. This technology is characterized by high productivity, safety, suitability for small-sized trees, high recovery of timber, and environmental friendliness. About one fourth of the industrial timber in the whole world is harvested using the log-length system. The challenge of ecological sustainability, multiple use of forests, adoption of thinnings as a tool of management, trend toward improved utilization of forest biomass, and shift from natural forests to plantations all increase the global interest in the log-length system. The paper presents a review of the Finnish forest sector, the technology of timber harvesting and transport, productivity of logging work, and costs of timber at the mill. The highly mechanized logging systems of the forest industries and the lighter technology of self-employed forest owners are discussed separately. Furthermore, the use of residual biomass as a source of clean and renewable energy, the Finnish logging machine industry, and forest operations research in Finland are also reviewed. (46 refs., 35 figs., 8 tabs.)

Modeling the Effects of Knots in Structural Timber

DEFF Research Database (Denmark)

Foley, Christina

The main purpose of the pursued research presented in this thesis is to increase knowledge of the effects of knots in structural timber so that characteristics of weaker timber may be determined and applied to improve current grading techniques. In the process, a three-dimensional fiber paradigm...... are given to Shigo's knot formation theory, and thus predicts two separate patterns of fiber direction within annual growth layers related to live knots. In order to determine the possibility to practically and non destructively predict local material directions in structural timber with the three...... was established, which describes variations of radial growth direction and fiber orientation related to knots in timber. The adaptability of the paradigm allows practically any softwood knot and its effect on surrounding wood material to be modeled with an accuracy that is limited only by input data. The knot...

Study on the ventilation resistance of timbered airways (II)

Energy Technology Data Exchange (ETDEWEB)

Oba, S; Takiguchi, I

1977-01-01

From the results of a model study described in a previous paper (I), (Vol.23, No.4), a timber factor Kr is determined as a specific parameter for type of timber and as a function of spacing ratio d/e where d and e are the spacing and the height of sets respectively. A general formula for the determination of the friction coefficient of timbered airways is also proposed.

Carotid stenosis measurement on colour Doppler ultrasound: Agreement of ECST, NASCET and CCA methods applied to ultrasound with intra-arterial angiographic stenosis measurement

International Nuclear Information System (INIS)

Wardlaw, Joanna M.; Lewis, Steff

2005-01-01

Purpose: Carotid stenosis is usually determined on Doppler ultrasound from velocity readings. We wondered if angiography-style stenosis measurements applied to ultrasound images improved accuracy over velocity readings alone, and if so, which measure correlated best with angiography. Materials and methods: We studied prospectively patients undergoing colour Doppler ultrasound (CDU) for TIA or minor stroke. Those with 50%+ symptomatic internal carotid artery (ICA) stenosis had intra-arterial angiography (IAA). We measured peak systolic ICA velocity, and from the ultrasound image, the minimal residual lumen, the original lumen (ECST), ICA diameter distal (NASCET) and CCA diameter proximal (CCA method) to the stenosis. The IAAs were measured by ECST, NASCET and CCA methods also, blind to CDU. Results: Amongst 164 patients (328 arteries), on CDU the ECST, NASCET and CCA stenosis measures were similarly related to each other (ECST = 0.54 NASCET + 46) as on IAA (ECST = 0.6 NASCET + 40). Agreement between CDU- and IAA-measured stenosis was similar for ECST (r = 0.51), and CCA (r = 0.48) methods, and slightly worse for NASCET (r = 0.41). Adding IAA-style stenosis to the peak systolic ICA velocity did not improve agreement with IAA over peak systolic velocity alone. Conclusion: Angiography-style stenosis measures have similar inter-relationships when applied to CDU, but do not improve accuracy of ultrasound over peak systolic ICA velocity alone

System Reliability of Timber Structures with Ductile Behaviour

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Čizmar, Dean

2011-01-01

The present paper considers the evaluation of timber structures with the focus on robustness due to connection ductility. The robustness analysis is based on the structural reliability framework applied to a simplified mechanical system. The structural timber system is depicted as a parallel system....... An evaluation method of the ductile behaviour is introduced. For different ductile behaviours, the system reliability is estimated based on Monte Carlo simulation. A correlation between the strength of the structural elements is introduced. The results indicate that the reliability of a structural timber system...

Feasibility Investigation into Strengthening of Timber Bridge Stringers

Science.gov (United States)

2007-05-01

12 Studies on timber members recycled from old timber structures...55 Figure 63. The load cell-hydraulic ram setup with spreader beam.....................................................56 Figure 64. The MTS...actuator and spreader beam................................................................................56 Figure 65. Effectiveness of a repair method

Timber price dynamics following a natural catastrophe

Science.gov (United States)

Jeffrey P. Prestemon; Thomas P. Holmes

2000-01-01

Catastrophic shocks to existing stocks of a renewable resource can cause long-run price shifts. With timber, these long-run price shifts may be accompanied by a short-run price drop due to salvage. Hurricane Hugo damaged 20 percent of southern pine timber in the South Carolina Coastal Plain in 1989. To estimate the...

Protection of timber constructions by using electro osmotic pulsing technology (PLEOT)

OpenAIRE

Treu, A.; Larnoy, E.; Ribeiro Nunes, L. M.; Duarte, S.; Halvorsen, H.

2011-01-01

Timber constructions are often built in combination with other materials such as concrete. These materials can influence the timber construction. Moist concrete can e.g. lead to development of molds which creates an unhealthy living area for people. Furthermore, moisture in wood buildings can negatively affect the wood material, which can lead to negative biological activity in timber and possible reduction of strength properties of timber constructions. The present paper introduces ...

Economic implications of manufacturing sawed ties and timbers

Science.gov (United States)

Lawrence D. Garrett; Lawrence D. Garrett

1969-01-01

The purpose of this paper is to discuss those factors that affect the profitability of manufacturing timbers and show that the combined manufacture of both lumber and timbers will provide a greater daily income than the manufacture of lumber alone.

Optimal control of raw timber production processes

Science.gov (United States)

Ivan Kolenka

1978-01-01

This paper demonstrates the possibility of optimal planning and control of timber harvesting activ-ities with mathematical optimization models. The separate phases of timber harvesting are represented by coordinated models which can be used to select the optimal decision for the execution of any given phase. The models form a system whose components are connected and...

Effect of timber supplies on the efficiency of coal mining

Energy Technology Data Exchange (ETDEWEB)

Kulish, S A; Ponikarov, V D

1977-01-01

An analysis is made of the system of supplying coal mining production associations with timber materials. The potential for greater efficiency in the use and processing of timber is indicated. The possibility of using methods of mathematical modelling and forecasting to improve the efficiency of supplying timber to coal associations is demonstrated. 1 table.

RILEM International Symposium on Materials and Joints in Timber Structures

CERN Document Server

Reinhardt, H-W; Garrecht, Harald

2014-01-01

This book contains the contributions from the RILEM International Symposium on Materials and Joints in Timber Structures that was held in Stuttgart, Germany from October 8 to 10, 2013. It covers recent developments in the materials and the joints used in modern timber structures. Regarding basic wooden materials, the contributions highlight the widened spectrum of products comprising cross-laminated timber, glulam and LVL from hardwoods and block glued elements. Timber concrete compounds, cement bonded wood composites and innovative light-weight constructions represent increasingly employed alternatives for floors, bridges and facades. With regard to jointing technologies, considerable advances in both mechanical connections and glued joints are presented. Self-tapping screws have created unprecedented options for reliable, strong as well as ductile joints and reinforcement technologies. Regarding adhesives, which constitute the basis of the jointing/laminating technology of modern timber products, extended o...

Reliability-Based Calibration of Load Duration Factors for Timber Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Svensson, Staffan; Stang, Birgitte Friis Dela

2005-01-01

John Dalsgaard Sørensen, Staffan Svensson, Birgitte Dela Stang : Reliability-Based Calibration of Load Duration Factors for Timber Structures     Abstract :   The load bearing capacity of timber structures decrease with time depending on the type of load and timber. Based on representative limit...... states and stochastic models for timber structures, load duration factors are calibrated using probabilistic methods. Load duration e.ects are estimated on basis of simulation of realizations of wind, snow and imposed loads in accordance with the load models in the Danish structural codes. Three damage...... accumulation models are considered, namely Gerhards model, Barrett and Foschi _ s model and Foschi and Yao _ s model. The parameters in these models are .tted by the Maximum Likelihood Method using data relevant for Danish structural timber and the statistical uncertainty is quanti .ed. The reliability...

A Pseudoproxy-Ensemble Study of Late-Holocene Climate Field Reconstructions Using CCA

Science.gov (United States)

Amrhein, D. E.; Smerdon, J. E.

2009-12-01

Recent evaluations of late-Holocene multi-proxy reconstruction methods have used pseudoproxy experiments derived from millennial General Circulation Model (GCM) integrations. These experiments assess the performance of a reconstruction technique by comparing pseudoproxy reconstructions, which use restricted subsets of model data, against complete GCM data fields. Most previous studies have tested methodologies using different pseudoproxy noise levels, but only with single realizations for each noise classification. A more robust evaluation of performance is to create an ensemble of pseudoproxy networks with distinct sets of noise realizations and a corresponding reconstruction ensemble that can be evaluated for consistency and sensitivity to random error. This work investigates canonical correlation analysis (CCA) as a late-Holocene climate field reconstruction (CFR) technique using ensembles of pseudoproxy experiments derived from the NCAR CSM 1.4 millennial integration. Three 200-member reconstruction ensembles are computed using pseudoproxies with signal-to-noise ratios (by standard deviation) of 1, 0.5, and 0.25 and locations that approximate the spatial distribution of real-world multiproxy networks. An important component of these ensemble calculations is the independent optimization of the three CCA truncation parameters for each ensemble member. This task is accomplished using an inexpensive discrete optimization algorithm that minimizes both RMS error in the calibration interval and the number of free parameters in the reconstruction model to avoid artificial skill. Within this framework, CCA is investigated for its sensitivity to the level of noise in the pseudoproxy network and the spatial distribution of the network. Warm biases, variance losses, and validation-interval error increase with noise level and vary spatially within the reconstructed fields. Reconstruction skill, measured as grid-point correlations during the validation interval, is lowest in

Tensile properties of machine strength graded timber for glued laminated timber

DEFF Research Database (Denmark)

Boström, Lars; Hoffmeyer, Preben; Solli, Kjell-Helge

1999-01-01

Special setting values based on tensile properties of Norway spruce are established for four different strength grading machines. The machines included are Computermatic, Cook-Bolinder, Ersson and Dynagrade.The study shows that the yield of timber to be used in tension, such as laminations...

Finite element analysis of composite concrete-timber beams

Directory of Open Access Journals (Sweden)

N. C. S. FORTI

Full Text Available AbstractIn the search for sustainable construction, timber construction is gaining in popularity around the world. Sustainably harvested wood stores carbon dioxide, while reforestation absorbs yet more CO2. One technique involves the combination of a concrete slab and a timber beam, where the two materials are assembled by the use of flexible connectors. Composite structures provide reduced costs, environmental benefits, a better acoustic performance, when compared to timber structures, and maintain structural safety. Composite structures combine materials with different mechanical properties. Their mechanical performance depends on the efficiency of the connection, which is designed to transmit shear longitudinal forces between the two materials and to prevent vertical detachment. This study contributes with the implementation of a finite element formulation for stress and displacement determination of composite concrete-timber beams. The deduced stiffness matrix and load vector are presented along to numerical examples. Numerical examples are compared to the analytical equations available in Eurocode 5 and to experimental data found in the literature.

Estudio psicométrico del Cuestionario de Conducta Antisocial (CC-A en adolescentes tempranos de Tucumán, Argentina

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Ana Betina Lacunza

2016-01-01

Full Text Available El comportamiento antisocial se refiere a una diversidad de actos que infringen las normas sociales y de convivencia. Su delimitación está dada tanto por la valoración social de la gravedad de los comportamientos como por su alejamiento a las pautas normativas de una sociedad. El objetivo de este trabajo fue analizar las propiedades psicométricas del cuestionario de Conducta Antisocial (CC-A en adolescentes de Tucumán, Argentina. Se aplicó el CC-A y la Batería de Socialización BAS-3 a quinientos once adolescentes escolarizados de once y doce años. Se encontró una solución de tres factores que explicaban el 35 % de la varianza, congruente con la propuesta original. Los coeficientes Alpha de Cronbach fueron adecuados en Agresividad (.735, Aislamiento (.769 y Ansiedad/Retraimiento (.681, y se establecieron relaciones entre CC-A y BAS-3. Así mismo, se observaron correlaciones negativas entre Agresividad, Consideración con los demás y Autocontrol mientras que fueron positivas entre Aislamiento y Retraimiento. Posteriormente, se determinaron las categorías percentilares de esta versión (CC-A de ventiocho ítems; 18% de los adolescentes presentaban percentiles de riesgo en Agresividad mientras que un 20.9% lo hacía en Aislamiento. El estudio aporta datos con respecto a las propiedades psicométricas del instrumento en población local, indicando su sensibilidad para la evaluación del comportamiento antisocial.

Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania

DEFF Research Database (Denmark)

Partal, Miriam Casacuberta; Kinunghi, Safari; Vennervald, Birgitte J

2016-01-01

of Lake Victoria in Mwanza Region, Tanzania, and to optimize the reading of the POC-CCA test lines by using a computer software image analysis. Initially, a pilot study in 106 school children indicated that time of urine collection did not have an impact on CCA results as 84.9% (90) had identical scores...... POC-CCAs were compared to six Kato-Katz smears (75.0% vs. 42.6%; p reading of the POC-CCA, a Software...... tool (Image Studio Lite®) was used to read and quantify the colour (expressed as pixels) of the test line on all positive tests, showing a positive correlation between number of pixels and the visually scored intensities and between number of pixels and egg counts. In conclusion, the POC-CCA assay...

Crystal structures of CCa2CuO5 and CSr1.9Ca1.1Cu2O7 refined from single crystal data

International Nuclear Information System (INIS)

Kopnin, E.M.; Matveev, A.T.; Salamakha, P.S.; Sato, A.; Takayama-Muromachi, E.

2003-01-01

Single crystals were grown for new layered oxycarbonates CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7 at 6 GPa using a belt-type apparatus. Their crystal structures were determined using single crystal X-ray diffraction data with R1(wR2)=0.0294(0.0659) and 0.0199(0.0457) for CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7 , respectively. These phases crystallize in the space group P4/mmm (No. 123), Z=1 with a=3.8157(1) Angst, c=7.1426(3) Angst for CCa 2 CuO 5 and a=3.8753(1) Angst, c=10.6765(5) Angst for CSr 1.9 Ca 1.1 Cu 2 O 7 . In contrast to CSr 2 CuO 5 , no ordering in the orientation of the triangular CO 3 groups was revealed in CCa 2 CuO 5 and CSr 1.9 Ca 1.1 Cu 2 O 7

[Influence of elevated homocystein level and selected lipid parameters in kidney transplant patients on the progression of atherosclerotic changes assessed by intima-media thickness index (CCA-IMT)].

Science.gov (United States)

Janda, Katarzyna; Aksamit, Dariusz; Drozdz, Maciej; Krzanowski, Marcin; Ignacak, Ewa; Kowalczyk-Michałek, Martyna; Tabor-Ciepiela, Barbara; Sułowicz, Władysław

2012-01-01

The aim of the study was to evaluate the influence of elevated homocystein (Hcy) level and selected lipid parameters on the progression of atherosclerotic changes in patients after kidney transplantation (KTx). The study included 51 pts (17 F, 34 M) aged 15-62 years (median 38.1) after cadaver KTx. The mean observation period equaled 21.2 months (6-24 months); while total observation period was 90 patients/ years. Hcy levels was measured using HPLC, Lp(a) and Apo-B levels using the nephelometric method and total cholesterol with its' HDL and LDL fractions, triglycerides and creatinine based on the Hitachi 917 analyzer. Patients' blood was drawn before renal transplantation and 3, 6, 9, 12, 15, 18, 21 and 24 months after KTx. Common carotid artery intima media thickness (CCA-IMT) was evaluated by ultrasound on 14 days, 12 and 24 months after KTx. CCA-IMT correlated significantly with Hcy levels after 12 months (R=0.53; p=0.0009) and 24 months (R=0.38; p=0.0356) after KTx. Significant differences were found 12 and 24 months after KTx in CCA-IMT between patients with normal (15 micromol/ l) mean Hcy concentrations: p=0.0035 and p= 0.015, respectively. Analyzing changes in CCA-IMT, significant differences were noted when comparing the CCA-IMT increment after 12 and 24 months post KTx in patients with normal (15 micromol/l) homocystein concentrations: p=0.049 and p=0.0039, respectively. Increment of CCA-IMT 12 months after KTx, significantly correlated with mean total cholesterol level (R=0.35; p=0.0333), whereas 24 months after procedure correlated significantly with 0.0315). Hcy level is an independent risk factor for atherosclerosis development in patients after KTx. Elevated Hcy level as well as increased cholesterol and Lp(a) levels enhance the progression of atherosclerotic changes evaluated by CCA-IMT in KTx patients.

Finite-Element Modeling of Timber Joints with Punched Metal Plate Fasteners

DEFF Research Database (Denmark)

Ellegaard, Peter

2006-01-01

The focus of this paper is to describe the idea and the theory behind a finite-element model developed for analysis of timber trusses with punched metal plate fasteners (nail plates). The finite-element model includes the semirigid and nonlinear behavior of the joints (nonlinear nail and plate...... elements) and contact between timber beams, if any (bilinear contact elements). The timber beams have linear-elastic properties. The section forces needed for design of the joints are given directly by the finite-element model, since special elements are used to model the nail groups and the nail plate...... the behavior of the joints very well at lower load levels. At higher load levels the stiffness is overestimated due to development of cracks in the timber and the linear-elastic timber properties in the finite-element model....

A new version of code Java for 3D simulation of the CCA model

Science.gov (United States)

Zhang, Kebo; Xiong, Hailing; Li, Chao

2016-07-01

In this paper we present a new version of the program of CCA model. In order to benefit from the advantages involved in the latest technologies, we migrated the running environment from JDK1.6 to JDK1.7. And the old program was optimized into a new framework, so promoted extendibility.

Spatial ecology of timber rattlesnakes on the hardwood ecosystem experiment: pre-treatment results

Science.gov (United States)

Brian J. MacGowan; Zachary J. Walker

2013-01-01

The timber rattlesnake (Crotalus horridus) is a species of conservation concern throughout much of its geographic range and may serve as a sentinel species in investigations of the effects of timber harvesting on forest reptiles. Our objective was to determine the effect of even-aged timber management regimes on timber rattlesnake home range and...

Impacts on South Carolina timber production over the last five decades.

Science.gov (United States)

Jinglong Mo; Thomas Straka; Richard Harper

2013-01-01

Timberland ownership patterns and national forest timber harvesting policy have undergone significant changes in South Carolina over the past five decades. Timber output studies for the state commonly focused on short time frames and seldom addressed timberland ownership patterns in detail. We describe fifty-year timber output for South Carolina, allowing us to address...

Influence of steaming on drying quality and colour of beech timber

Directory of Open Access Journals (Sweden)

Milić Goran

2015-01-01

Full Text Available This paper presents the results of an analysis of influence of the “light” steaming process on conventional drying and colour of beech timber. A stack consisting of steamed and unsteamed boards was dried. Moisture content and moisture content profiles were recorded, and at the end of drying final moisture content, moisture content difference across thickness, case-hardening and colour were determinated. No statistically significant difference between steamed and unsteamed timber was established in any of the examined parameters (MC, ΔMC, gap. The results indicate that equal (or even better drying quality can be expected with steamed beech timber than with unsteamed timber, given the same drying schedule. Dry steamed timber was darker and more reddish than the unsteamed one. An imprecision of measurement by probes in the kiln was noticed in measuring steamed and unsteamed beech timber having a moisture content of between 7% and 15%, and a solution for overcoming this problem was given. [Projekat Ministarstva nauke Republike Srbije, br. TR 31041

Alaska's timber harvest and forest products industry, 2005

Science.gov (United States)

Jeff M. Halbrook; Todd A. Morgan; Jason P. Brandt; Charles E. Keegan; Thale Dillon; Tara M. Barrett

2009-01-01

This report traces the flow of timber harvested in Alaska during calendar year 2005, describes the composition and operations of the state's primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, and sales of primary wood products....

Robustness Analysis of Timber Truss Structure

DEFF Research Database (Denmark)

Rajčić, Vlatka; Čizmar, Dean; Kirkegaard, Poul Henning

2010-01-01

The present paper discusses robustness of structures in general and the robustness requirements given in the codes. Robustness of timber structures is also an issues as this is closely related to Working group 3 (Robustness of systems) of the COST E55 project. Finally, an example of a robustness...... evaluation of a widespan timber truss structure is presented. This structure was built few years ago near Zagreb and has a span of 45m. Reliability analysis of the main members and the system is conducted and based on this a robustness analysis is preformed....

Growing Timber Structures

DEFF Research Database (Denmark)

Tamke, Martin; Evers, Henrik Leander; Stasiuk, David

2013-01-01

The contemporary design of timber structures has to answer questions concerning structural stability, production impact and energy implications in ever earlier stages. The interrelation of these levels creates a complexity that is difficult to resolve through contemporary linear parametric...... to integrate the behaviour of networked systems into structures made from wooden material....

Architectural and structural qualities in timber joints

DEFF Research Database (Denmark)

Christensen, Jesper Thøger; Christensen, Mogens Fiil; Damkilde, Lars

2016-01-01

Design of joints in timber structures is crucial to reach both elegant and structural efficient designs. Design of joints should therefore be an integral part of the conceptual design phase. Traditionally this is not the case, and joints are often solely designed and analysed in the engineering...... but also increase timbers competitiveness in the building industry. The paper is part of an ongoing research project aiming at providing tools for an integrated design process for timber structures. The focus of the paper is to identify how structure and its joints contributes to architecture and vice...... design phase. The result is joints that function structurally but do not add value to the design, and may even compromise the architectural ideas. With an approach, integrating both structural and architectural design from the beginning, one should not only gain better structures and architecture...

Comparative durability of timber bridges in the USA

Science.gov (United States)

James P. Wacker; Brian K. Brashaw

2017-01-01

As engineers begin to utilize life-cycle-cost design approaches for timber bridges, there is a necessity for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was...

Cattle and elk responses to intensive timber harvest.

Science.gov (United States)

Michael J. Wisdom; Bruce K. Johnson; Martin Vavra; Jennifer M. Boyd; Priscilla K. Coe; John G. Kie; Alan A. Ager; Norman J. Cimon

2004-01-01

Forested habitats for cattle and elk (Cervus elaphus) in the western United States have changed substantially in response to intensive timber management during the latter half of the 20th century. Consequently, the subject of how elk and other ungulates respond to timber management is a high-profile, long-standing issue that continues to be studied...

Whole tree transportation system for timber processing depots

Science.gov (United States)

John Lancaster; Tom Gallagher; Tim  McDonald; Dana Mitchell

2016-01-01

The growing demand for alternative energy has led those who are interested in producing sustainable energy from renewable timber to devise new concepts to satisfy those demands. The concept of timber processing depots, where whole stem trees will be delivered for future processing into wood products and high quality energy fuel, has led to the re-evaluation of our...

metaCCA: summary statistics-based multivariate meta-analysis of genome-wide association studies using canonical correlation analysis.

Science.gov (United States)

Cichonska, Anna; Rousu, Juho; Marttinen, Pekka; Kangas, Antti J; Soininen, Pasi; Lehtimäki, Terho; Raitakari, Olli T; Järvelin, Marjo-Riitta; Salomaa, Veikko; Ala-Korpela, Mika; Ripatti, Samuli; Pirinen, Matti

2016-07-01

A dominant approach to genetic association studies is to perform univariate tests between genotype-phenotype pairs. However, analyzing related traits together increases statistical power, and certain complex associations become detectable only when several variants are tested jointly. Currently, modest sample sizes of individual cohorts, and restricted availability of individual-level genotype-phenotype data across the cohorts limit conducting multivariate tests. We introduce metaCCA, a computational framework for summary statistics-based analysis of a single or multiple studies that allows multivariate representation of both genotype and phenotype. It extends the statistical technique of canonical correlation analysis to the setting where original individual-level records are not available, and employs a covariance shrinkage algorithm to achieve robustness.Multivariate meta-analysis of two Finnish studies of nuclear magnetic resonance metabolomics by metaCCA, using standard univariate output from the program SNPTEST, shows an excellent agreement with the pooled individual-level analysis of original data. Motivated by strong multivariate signals in the lipid genes tested, we envision that multivariate association testing using metaCCA has a great potential to provide novel insights from already published summary statistics from high-throughput phenotyping technologies. Code is available at https://github.com/aalto-ics-kepaco anna.cichonska@helsinki.fi or matti.pirinen@helsinki.fi Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

Robustness Analysis of a Timber Structure with Ductile Behaviour in Compression

DEFF Research Database (Denmark)

Čizmar, Dean; Sørensen, John Dalsgaard; Kirkegaard, Poul Henning

2011-01-01

This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness assessment. The complex timber structure with a large number of failure modes...... material ductility of timber is taken into account. The robustness is expressed and evaluated by a robustness index....

The 1993 timber assessment market model: structure, projections, and policy simulations.

Science.gov (United States)

Darius M. Adams; Richard W. Haynes

1996-01-01

The 1993 timber assessment market model (TAMM) is a spatial model of the solidwood and timber inventory elements of the U.S. forest products sector. The TAMM model provides annual projections of volumes and prices in the solidwood products and sawtimber stumpage markets and estimates of total timber harvest and inventory by geographic region for periods of up to 50...

Historic timber skeleton structures and the local seismic culture

Science.gov (United States)

Bostenaru, M.

2009-04-01

This presentation deals with the employment of timber skeleton structure and the local seismic culture. After the 1755 earthquake in the reconstruction of Lisbon a type of building with timber skeleton and masonry infill called "gaiola pombalina" was promoted, since this was designed to better resists earthquakes. "Gaiola" means cage, and it was also named after the Marques de Pombal who introduced it in the reconstruction following the earthquake. The „gaiola pombalina" presents a timber skeleton with Saint Andrew crosses in the interior walls with masonry infill and thick masonry load bearing walls loosing in thickness to the upper floors in the exterior walls. The masonry can fall out during earthquakes but the building remains staying given the interior timber skeleton. The type of buildings with timber structure and (masonry) infill behaved well in earthquakes in various parts of the earth, like Nepal (the dhaji dewary type), Pakistan, Turkey (the himiş type after the 1999 earthquake) [both latter types were researched by Langenbach, www.conservationtech.com and www.traditional-is-modern.net] and also in Germany after the 1356 earthquake (the Southern German subtype of Fachwerk). Also in Italy a subtype called "casa baraccata" was promoted in a construction code to a similar time (following the 1783 earthquake in Southern Italy, see Tobriner 1983) as that of the "gaiola pombalina", the time of the Baroque, when town planning acquired another status. Unlike at the "gaiola pombalina" the "casa baraccata" the timber skeleton is at the exterior walls. For this reason this type of buildings is considered to be an expression of the local seismic culture. However, this type of buildings is common also for areas where seismic risk is not an issue, like half-timbered in England and the northern subtype of Fachwerk in Northern Germany, and in some high seismic risk regions with mountains and timber resources like Romania is not spread. Given these premises the author

Supply Chain Planning for a Timber Harvesting Plus Sale Tender

Directory of Open Access Journals (Sweden)

Josef Holoubek

2015-01-01

Full Text Available Since 2010, the Czech State Forest Enterprise has been inviting timber-harvesting tenders while insisting on the forestry company purchasing the timber from the felled trees as well. To win, a tender must offer the greatest difference between the price of the timber purchased and the cost of the operations. Thus, the forest companies are now facing new problem: apart from minimizing the logging costs they are searching for a cross-cutting and mill-distribution strategy that maximizes the selling price of the harvested timber. The optimization model devised by the present paper provides support for finding an optimal timber selling strategy and, as an important contribution, include a detailed plan for cross-cutting the logs and assign them to the particular customers. We keep the support accessible via common office software and the cross-cutting and customer-assigning problem is formulated as a linear programming model for EXCEL, a particular real-world problem is solved and, using expert comparison, the model appears to provide very good results.

On calculating the pressure on cylindrical timbers of vertical shafts in clayey soils

Energy Technology Data Exchange (ETDEWEB)

Mizyumskii, V A

1979-11-01

In order to calculate the pressure built up on timbers which have been constructed to hold back freely moving soil in a clay environment, a formula is recommended which characterizes the state of clayey soil. The formula incorporates the parameters for volume information, momentary and long displacement modulus, decay factor of deformations of the after effect, viscosity factor in the starting zone of reforming. Because the timber creates a reaction pressure on the contour of the working, the radial travel of the timber is calculated and then the pressure on the timber. Correlation of the calculated pressure with the results of measurements in workings showed that the pressure of clayey soil on the timber is the result of viscous flow deformations. Disregarding these deformations, the pressures on the shaft timbering in the Yuzhno-Belozerskii deposit were calculated at 0.004 and 0.006 tons/m/sup 2/ respectively at a depth of 90 and 142 meters. After reworking the soil and setting up timbering the pressure was calculated at 2/3 of that of the highest measurements. The formula suggested is suitable for determining pressure on timbers having a large creep. (12 refs.) (In Russian)

Wisconsin timber industry--an assessment of timber product output and use, 1988.

Science.gov (United States)

W. Brad Smith; James W. Whipple

1990-01-01

Discusses recent Wisconsin forest industry trends; production and receipts of pulpwood, saw logs, and veneer logs; and production of other timber products in 1988. Reports on logging residue, on wood and bark residue generated at primary wood-using mills, and on disposition of this mill residue.

Improvement of POC-CCA Interpretation by Using Lyophilization of Urine from Patients with Schistosoma mansoni Low Worm Burden: Towards an Elimination of Doubts about the Concept of Trace.

Directory of Open Access Journals (Sweden)

Paulo Marcos Zech Coelho

2016-06-01

Full Text Available Accurate diagnostic techniques for schistosomiasis are essential for prevalence determination and identification of positive patients. A point-of-care test for detecting schistosome circulating cathodic antigen (POC-CCA has been evaluated for its accuracy in different endemic regions. This reagent strip/dipstick based assay has showed high sensitivity for individuals with high or moderate worm burden, but the interpretation of light infections is less clear, especially for trace readings.We introduced a urine lyophilization step to the POC-CCA assay to improve its sensitivity and clarify the interpretation of traces. We evaluated POC-CCA sensitivity and specificity within individuals with low parasite burdens in a Brazilian endemic area where a high number of traces were detected. Patients that were positive for other helminths were also evaluated for cross reactions. In all cases, a combined parasitological diagnosis using Kato-Katz (24 slides and Saline Gradient (1 g of feces were used as reference. At baseline, diagnosis by POC-CCA (1-2 cassettes showed 6% sensitivity, inaccurately predicting a low prevalence of Schistosoma mansoni infections (2 POC-CCA positives/32 egg positives. After urine lyophilization, the sensitivity was increased significantly (p < 0.05. Prevalence rates changed from 2% to 32% (27 POC-CCA positives/32 egg positives, equivalent to parasitological techniques. Most of the trace readings changed to positive after lyophilization while some negatives turned into traces. Cross reaction analysis confirmed the specificity of POC-CCA.Trace readings cannot be primarily defined as positive or negative cases. It is critical to verify case-by-case by concentrating urine 10 fold by lyophilization for the diagnosis. Following lyophilization, persistent trace readings should be read as negatives. No trained technician is needed and cost is restricted to the cost of a lyophilizer and the electricity to run it.

WELFARE IMPLICATIONS OF TIMBERLAND OWNERSHIP CHANGES IN THE U.S. TIMBER MARKETS

Directory of Open Access Journals (Sweden)

Mohammad Mahfuzur Rahman

2016-07-01

Full Text Available In the last two decades, many forest product firms in the U.S. either divested their timberlands to timber investment management organizations (TIMOs and conservation organizations or converted their corporate structures from C corporations to real estate investment trusts (REITs. All landowners sold smaller timberland tracts for nonforestry uses. Reduced timber supplies from conservation organizations and timberland loss to other nonforestry uses have consequences on producer and consumer surpluses in the U.S. timber markets. Equilibrium displacement model has been employed to evaluate the welfare changes in U.S. timber markets attributed to timberland ownership changes. Net reduction of timber supply contributed to the reduction of social surplus by $43 million in 2006. Compared to the $33 billion plus U.S. timber markets, this welfare reduction was small. Overall, this article explains the shifts of economic surpluses among producers and net surplus reduction for the society attributed to timberland ownership changes in the United States.

CCA 3101/4101 Environmental Humanities: The History of a Unit through an Ecopedagogical Lens

Science.gov (United States)

Ryan, John Charles

2012-01-01

In 2011 the author taught, for the first time, the well-established unit CCA3101/4101 Environmental Humanities in the School of Communications and Arts at ECU (Edith Cowan University) in Western Australia. The unit has a 20-year history through associate professor Rod Giblett and parallels the development of the environmental humanities as a field…

Lateral testing of glued laminated timber tudor arch

Science.gov (United States)

Douglas R. Rammer; Philip Line

2016-01-01

Glued laminated timber Tudor arches have been in wide use in the United States since the 1930s, but detailed knowledge related to seismic design in modern U.S. building codes is lacking. FEMA P-695 (P-695) is a methodology to determine seismic performance factors for a seismic force resisting system. A limited P-695 study for glued laminated timber arch structures...

Non-timber forest products and forest stewardship plans

Science.gov (United States)

Becky Barlow; Tanner Filyaw; Sarah W. Workman

2015-01-01

To many woodland owners “harvesting” typically means the removal of timber from forests. In recent years many landowners have become aware of the role non-timber forest products (NTFPs) can play in supplemental management strategies to produce income while preserving other forest qualities. NTFPs are a diverse group of craft, culinary, and medicinal products that have...

The functional interplay between protein kinase CK2 and CCA1 transcriptional activity is essential for clock temperature compensation in Arabidopsis.

Directory of Open Access Journals (Sweden)

Sergi Portolés

2010-11-01

Full Text Available Circadian rhythms are daily biological oscillations driven by an endogenous mechanism known as circadian clock. The protein kinase CK2 is one of the few clock components that is evolutionary conserved among different taxonomic groups. CK2 regulates the stability and nuclear localization of essential clock proteins in mammals, fungi, and insects. Two CK2 regulatory subunits, CKB3 and CKB4, have been also linked with the Arabidopsis thaliana circadian system. However, the biological relevance and the precise mechanisms of CK2 function within the plant clockwork are not known. By using ChIP and Double-ChIP experiments together with in vivo luminescence assays at different temperatures, we were able to identify a temperature-dependent function for CK2 modulating circadian period length. Our study uncovers a previously unpredicted mechanism for CK2 antagonizing the key clock regulator CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1. CK2 activity does not alter protein accumulation or subcellular localization but interferes with CCA1 binding affinity to the promoters of the oscillator genes. High temperatures enhance the CCA1 binding activity, which is precisely counterbalanced by the CK2 opposing function. Altering this balance by over-expression, mutation, or pharmacological inhibition affects the temperature compensation profile, providing a mechanism by which plants regulate circadian period at changing temperatures. Therefore, our study establishes a new model demonstrating that two opposing and temperature-dependent activities (CCA1-CK2 are essential for clock temperature compensation in Arabidopsis.

Infill Panels and the tube connection in timber frames

NARCIS (Netherlands)

Leijten, A.J.M.; Jorissen, A.J.M.; Hoenderkamp, J.C.D.

2012-01-01

In recent years timber infill panels have been proposed for multi-story column-beam frame structures with the aim to substitute the stabilizing function of column-beam moment connections. The preliminary study reported in this paper considers a column-beam timber frame where stability is assured by

Lateral Stiffness of Timber Frames with CLT Infill Panels

NARCIS (Netherlands)

Leijten, A.J.M.; Jorissen, A.J.M.; Hoenderkamp, J.C.D.; Haddad, Y.M.

2011-01-01

In recent years timber infill panels have been proposed for multi-story column-beam frame structures with the aim to substitute the stabilizing function of column-beam moment connections. The preliminary study reported in this paper considers a column-beam timber frame where stability is assured by

Multi-Scalar Modelling for Free-form Timber Structures

DEFF Research Database (Denmark)

Poinet, Paul; Nicholas, Paul; Tamke, Martin

2016-01-01

.The research explores the design probe of free-form structures composed of glue-laminated timber beams and looks at the different types of data that need to be shared among each discipline and across multiple scales from which different levels of resolution can be defined. A particular focus lies...... in the segmentation strategy of glue-laminated timber structures that depend on structural requirements and the different types of constraints related to fabrication, transportation and assembly. Where current working practices decouple segmentation processes within a discrete digital workflow, this research aims...... and techniques as a means to work within a continuous design environment in which an abstract network of timber beams is iteratively updated through geometrical and structural optimizations at different levels of resolution....

Timber Regulation and Value Chain in Community-Based Timber Enterprise and Smallholder Forestry in the Philippines

Directory of Open Access Journals (Sweden)

Juan M. Pulhin

2016-07-01

Full Text Available Forest tenure reform has no doubt attained significant gains in promoting social justice and equity in the forest sector, through legal recognition of the communities’ property rights over forest lands in many developing countries. This includes the right to harvest and market trees that the communities planted. Along these lines, the Philippines’ community-based forest management (CBFM and smallholder forestry have the potential to meet the country’s wood demand and contribute to its poverty alleviation goal. Realities on the ground, however, make this lofty aspiration seems too far-fetched. Formal and informal barriers along the timber value chain restrict the growth and obstruct opportunities for community-based timber enterprises (CBTEs and smallholder forestry. Using the case of CBFM and smallholder forestry in the Visayas and Mindanao Islands in the Philippines, respectively, this paper examines the hurdles posed by regulations and informal practices, such as restrictive policies and increased transaction costs, through a segment analysis of the timber value chain. It argues that failure to address these barriers would lead to the decline of CBTEs and smallholder enterprises, thus undermining the merits of the forest tenure reform.

Total Weight and Axle Loads of Truck Units in the Transport of Timber Depending on the Timber Cargo

Directory of Open Access Journals (Sweden)

Grzegorz Trzciński

2018-03-01

Full Text Available When transporting timber, the high variability of species, assortments and moisture content of the wood raw material does not allow the weight of the transported timber to be precisely determined. This often contributes to the excessive weight loading of the entire truck unit. The aim of the research is to present the variability of the total weight of truck units with wood cargoes (GVW—gross vehicle weight depending on the weight of the empty unit and the transported timber load, as well as to analyze the changes in GVW, unit loads of wood and load on individual truck unit axles depending on the season. This study analyzes the total weight of truck units for 376 transports of Scots pine timber at different times of the year. The total weight of the truck units depends on the weight of an empty unit and the weight of the load. GVW was determined by using a weighbridge to weigh the vehicles and then the empty unit after unloading. The weight of the load was obtained as the difference between GVW and the tare. It was found that GVW differed significantly depending on the truck unit used, ranging from 43.60–58.80 Mg, often exceeding permissible limits for public roads. The individual axle loads for various truck units were also analyzed. The obtained results indicate that these loads are more equally distributed in the case of five-axle trucks compared to six-axle ones.

Forensic timber identification: It's time to integrate disciplines to combat illegal logging

Science.gov (United States)

Eleanor E. Dormontt; Markus Boner; Birgit Braun; Gerhard Breulmann; Bernd Degen; Edgard Espinoza; Shelley Gardner; Phil Guillery; John C. Hermanson; Gerald Koch; Soon Leong Lee; Milton Kanashiro; Anto Rimbawanto; Darren Thomas; Alex C. Wiedenhoeft; Yafang Yin; Johannes Zahnen; Andrew J. Lowe

2015-01-01

The prosecution of illegal logging crimes is hampered by a lack of available forensic timber identification tools, both for screening of suspectmaterial and definitive identification of illegally sourcedwood. Reputable timber traders are also struggling to police their own supply chains and comply with the growing requirement for due diligence with respect to timber...

Temporal Decay in Timber Species Composition and Value in Amazonian Logging Concessions.

Science.gov (United States)

Richardson, Vanessa A; Peres, Carlos A

2016-01-01

Throughout human history, slow-renewal biological resource populations have been predictably overexploited, often to the point of economic extinction. We assess whether and how this has occurred with timber resources in the Brazilian Amazon. The asynchronous advance of industrial-scale logging frontiers has left regional-scale forest landscapes with varying histories of logging. Initial harvests in unlogged forests can be highly selective, targeting slow-growing, high-grade, shade-tolerant hardwood species, while later harvests tend to focus on fast-growing, light-wooded, long-lived pioneer trees. Brazil accounts for 85% of all native neotropical forest roundlog production, and the State of Pará for almost half of all timber production in Brazilian Amazonia, the largest old-growth tropical timber reserve controlled by any country. Yet the degree to which timber harvests beyond the first-cut can be financially profitable or demographically sustainable remains poorly understood. Here, we use data on legally planned logging of ~17.3 million cubic meters of timber across 314 species extracted from 824 authorized harvest areas in private and community-owned forests, 446 of which reported volumetric composition data by timber species. We document patterns of timber extraction by volume, species composition, and monetary value along aging eastern Amazonian logging frontiers, which are then explained on the basis of historical and environmental variables. Generalized linear models indicate that relatively recent logging operations farthest from heavy-traffic roads are the most selective, concentrating gross revenues on few high-value species. We find no evidence that the post-logging timber species composition and total value of forest stands recovers beyond the first-cut, suggesting that the commercially most valuable timber species become predictably rare or economically extinct in old logging frontiers. In avoiding even more destructive land-use patterns, managing

Design of timber groynes

NARCIS (Netherlands)

Perdok, U.; Crossman, M.; Verhagen, H.J.; Howard, S.; Simm, J.

2003-01-01

The performance and durability of timber groynes (or 'groins') is highly dependent on the design and detailing of the structure. Using knowledge and experience developed over generations an effective functional design can be achieved, which may ultimately result in lower whole life costs and provide

The Level of Utilization of Secondary Timber Species among Furniture Producers

OpenAIRE

Antwi-Boasiako, Charles; Boadu, Kwadwo Boakye

2016-01-01

Background and Purpose: Inadequate supply of wood raw material is one of the major obstacles for the global furniture industry’s growth. Several secondary timbers/Lesser-Utilized-Species (LUS) that could substitute the scarce traditional timbers for furniture production exist in tropical forests. However, the industry continuously faces persistent timber shortages. The extent to which manufacturers utilize LUS as alternatives is unclear, which this study sought to ascertain. Materials and ...

Risks, Information and Short-Run Timber Supply

Directory of Open Access Journals (Sweden)

Francesca Rinaldi

2013-12-01

Full Text Available Efforts to increase wood mobilization have highlighted the need to appraise drivers of short-run timber supply. The current study aims to shed further light on harvesting decisions of private forest owners, by investigating optimal harvesting under uncertainty, when timber revenues are invested on financial markets and uncertainty is mitigated by news releases. By distinguishing between aggregate economic risk and sector specific risks, the model studies in great detail optimal harvesting-investment decisions, with particular emphasis on the non-trivial transmission of risk on optimal harvesting, and on the way private forest owners react to news and information. The analysis of the role played by information in harvesting decisions is a novelty in forest economic theory. The presented model is highly relevant from a policy—information is a commonly used forest policy instrument—as well as a practical perspective, since the mechanism of risk transmission is at the basis of timber pricing.

Innovative Use and Characterization of Polymers for Timber-Related Construction

Directory of Open Access Journals (Sweden)

Mark Evernden

2010-02-01

Full Text Available Timber gridshells have become a very popular, efficient, sustainable and beautiful structural application of timber. However, given the slender laths involved in this form of construction, there is concern over the durability of timber for this purpose, and Glass FRP (GFRP laths have been proposed as a possible substitution. This paper considers this possibility. It goes on to look at the possible use of Basalt FRP (BFRP for the same purpose, from the perspective of its creep characteristics. It is shown that the use of GFRP gridshells is a viable form of construction, and that enhanced durability characteristics of BFRP could lead to their adoption for gridshells, given that the creep characteristics of basalt fibres presented here are comparable to those of glass fibres. An altogether different form of timber construction is that of joist-and-floorboard. In the UK, there are thousands of historic buildings which use this floor construction, and a sizeable proportion of this building stock now requires upgrade, strengthening and/or stiffening to allow these buildings to be fit for purpose into the future. This paper goes on to consider the possible use of Carbon FRP (CFRP to strengthen and stiffen such timber floors. It is shown that such strengthening and stiffening is entirely feasible, offering the potential for greatly enhanced stiffness, in particular. Further, it is shown that mechanical shear connection between CFRP and timber is best conducted using perpendicular-positioned screws, rather than raked screws.

Innovative Use and Characterization of Polymers for Timber-Related Construction

Science.gov (United States)

Darby, Antony; Ibell, Tim; Evernden, Mark

2010-01-01

Timber gridshells have become a very popular, efficient, sustainable and beautiful structural application of timber. However, given the slender laths involved in this form of construction, there is concern over the durability of timber for this purpose, and Glass FRP (GFRP) laths have been proposed as a possible substitution. This paper considers this possibility. It goes on to look at the possible use of Basalt FRP (BFRP) for the same purpose, from the perspective of its creep characteristics. It is shown that the use of GFRP gridshells is a viable form of construction, and that enhanced durability characteristics of BFRP could lead to their adoption for gridshells, given that the creep characteristics of basalt fibres presented here are comparable to those of glass fibres. An altogether different form of timber construction is that of joist-and-floorboard. In the UK, there are thousands of historic buildings which use this floor construction, and a sizeable proportion of this building stock now requires upgrade, strengthening and/or stiffening to allow these buildings to be fit for purpose into the future. This paper goes on to consider the possible use of Carbon FRP (CFRP) to strengthen and stiffen such timber floors. It is shown that such strengthening and stiffening is entirely feasible, offering the potential for greatly enhanced stiffness, in particular. Further, it is shown that mechanical shear connection between CFRP and timber is best conducted using perpendicular-positioned screws, rather than raked screws.

Topology Optimization and Robotic Fabrication of Advanced Timber Space-frame Structures

DEFF Research Database (Denmark)

Søndergaard, Asbjørn; Amir, Oded; Eversmann, Phillip

2016-01-01

This paper presents a novel method for integrated topology optimization and fabrication of advanced timber space-frame structures. The method, developed in research collaboration between ETH Zürich, Aarhus School of Architecture and Israel Institute of Technology, entails the coupling of truss...... processes solving timber joint intersections, robotically controlling member prefabrication, and spatial robotic assembly of the optimized timber structures. The implication of this concept is studied through pilot fabrication and load-testing of a full scale prototype structure.......-based topology optimization with digital procedures for rationalization and robotic assembly of bespoke timber members, through a procedural, cross-application workflow. Through this, a direct chaining of optimization and robotic fabrication is established, in which optimization data is driving subsequent...

Compression strength perpendicular to grain of structural timber and glulam

DEFF Research Database (Denmark)

Damkilde, Lars; Hoffmeyer, Preben; Pedersen, Torben N.

1998-01-01

The characteristic strength values for compression perpendicular to grain as they appear in EN 338 (structural timber) and EN 1194 (glulam) are currently up for discussion. The present paper provides experimental results based on EN 1193 that may assist in the correct assignment of such strength...... values. The dominant failure mode of glulam specimens is shown to be fundamentally different from that of structural timber specimens. Glulam specimens often show tension perpendicular to grain failure before the compression strength value is reached. Such failure mode is not seen for structural timber....... Nonetheless test results show that the levels of characteristic compression strength perpendicular to grain are of the same order for structural timber and glulam. The values are slightly lower than those appearing in EN 1194 and less than half of those appearing in EN 338. The paper presents a numerical...

Seismic retrofitting of timber framed walls

Directory of Open Access Journals (Sweden)

Gonçalves, A. M.

2014-12-01

Full Text Available After the 1755 earthquake that destroyed Lisbon, an innovative anti-seismic structural system was developed consisting of a timber skeleton, that included timber framed masonry walls. After more than 250 years these structures need rehabilitation to face the present demands. The research presented in this paper aimed at experimentally characterizing the cyclic behaviour of timber framed walls reinforced with three different methods, namely: (i elastic-plastic dampers on diagonal braces, (ii reinforcement of timber connections with steel plates, (iii application of a reinforced rendering. The elastic-plastic damper showed an unsymmetrical behaviour and some difficulties to implement in practice. The strengthening with reinforced render led to an initial stiffness increase but showed a limited deformation capacity. The walls with reinforcing steel plates at the timber connections showed the best behaviour in terms of strength, stiffness and energy dissipation.Después del terremoto de 1755 que destruyó Lisboa, un sistema estructural antisísmico muy innovador fue desarrollado. El sistema consistió en un esqueleto de madera, que incluyó la construcción de muros de mampostería con un entramado de madera. Transcurridos más de 250 años, estas estructuras necesitan rehabilitación para poder hacer frente a los requisitos estructurales actuales. La investigación presentada en este trabajo tiene como objetivo caracterizar experimentalmente el comportamiento cíclico de los muros con entramado de madera reforzados con tres métodos diferentes: (i amortiguadores elasto-plásticos, (ii refuerzo de las conexiones de madera con placas de acero, (iii aplicación de un mortero reforzado. El amortiguador elasto-plástico mostró un comportamiento asimétrico y algunas dificultades para aplicarlo en la práctica. El refuerzo con mortero reforzado condujo a un aumento de la rigidez inicial, pero reveló una capacidad de deformación limitada. Los muros con

State forest timber sales in 2006

International Nuclear Information System (INIS)

Office National des Forets

2007-01-01

For the first time since the 1999 storms, forest owners have experienced a favourable market. The combination of buoyant demand for both industrial round-wood and timber and consolidation of supply led to a significant increase in prices. With a logging volume of 15 million m 3 (standing timber equivalent), state forest timber supply has remained at a high level, slightly above that of 1999. The improved business cycle situation has pushed prices up, including for beech for which rates had stagnated for some time. However, in spite of the 15% rise compared to 2005, the average per cubic metre price sold by the ONF (31.20 euros), all categories of timber and all state forests taken together, remains well below the average for the 1996-1999 period (37.80 euros). While unsold stocks have fallen considerably, the ONF has sought to facilitate access to products by industry by modernising its sales methods in line with the new 2005 legislative and regulatory provisions. Greater flexibility in the rules applicable to privately negotiated spot sales and supply contracts should over time contribute to stabilizing and reducing the accessory costs of supply. The changes implemented over the last decade in favour of private sales, which now account for nearly 40% of volumes sold, should continue in the future. Of those volumes, 20% were sold under supply contracts, a proportion that is rising sharply. These contracts covered more than one million m 3 in 2006, encouraging the ONF to adopt a new sales scheme and establish structures for consultations with both forest municipalities and the downstream component of the industry. (authors)

Development of a six-year research needs assessment for timber transportation structures

Science.gov (United States)

Terry J. Wipf; Michael A. Ritter; Sheila Rimal Duwadi; Russell C. Moody

1993-01-01

A timber bridge, once a thing of the past, is now becoming a thing of the present. Interest in timber bridges and other transportation structures has been rapidly increasing. Much of this is due to new technologies in design and construction as well as advances in material manufacturing and presevative treatments. Although timber bridges and other transportation...

Grip for sawing round timber

Energy Technology Data Exchange (ETDEWEB)

1982-07-01

This paper describes a device development at Gedling Colliery, Nottinghamshire Area, United Kingdom. It is a gripping attachment, designed to overcome the safety hazards involved in cross cutting timbers with a circular saw.

Some background of monitoring and NDT also useful for timber structures

OpenAIRE

Kurz, Jochen Horst; Boller, Christian

2015-01-01

Extension of the life of existing and historic timber structures has increased steadily in the last decade. Sustainability and low carbon emission have influenced activities in the construction industry. In the frame of the European COST Action FP 1101, several activities related to timber structures have been clustered. The COST Action FP 1101 consists of three working groups, namely Assessment (Working Group 1), Reinforcement (Working Group 2) and Monitoring (Working Group 3) of Timber Stru...

Comparative study of Nd:YAG laser-induced breakdown spectroscopy and transversely excited atmospheric CO2 laser-induced gas plasma spectroscopy on chromated copper arsenate preservative-treated wood.

Science.gov (United States)

Khumaeni, Ali; Lie, Zener Sukra; Niki, Hideaki; Lee, Yong Inn; Kurihara, Kazuyoshi; Wakasugi, Motoomi; Takahashi, Touru; Kagawa, Kiichiro

2012-03-01

Taking advantage of the specific characteristics of a transversely excited atmospheric (TEA) CO(2) laser, a sophisticated technique for the analysis of chromated copper arsenate (CCA) in wood samples has been developed. In this study, a CCA-treated wood sample with a dimension of 20 mm × 20 mm and a thickness of 2 mm was attached in contact to a nickel plate (20 mm × 20 mm × 0.15 mm), which functions as a subtarget. When the TEA CO(2) laser was successively irradiated onto the wood surface, a hole with a diameter of approximately 2.5 mm was produced inside the sample and the laser beam was directly impinged onto the metal subtarget. Strong and stable gas plasma with a very large diameter of approximately 10 mm was induced once the laser beam had directly struck the metal subtarget. This gas plasma then interacted with the fine particles of the sample inside the hole and finally the particles were effectively dissociated and excited in the gas plasma region. By using this technique, high precision and sensitive analysis of CCA-treated wood sample was realized. A linear calibration curve of Cr was successfully made using the CCA-treated wood sample. The detection limits of Cr, Cu, and As were estimated to be approximately 1, 2, and 15 mg/kg, respectively. In the case of standard LIBS using the Nd:YAG laser, the analytical intensities fluctuate and the detection limit was much lower at approximately one-tenth that of TEA CO(2) laser. © 2012 Optical Society of America

Mechanical Properties of Longleaf Pine Treated with Waterborne Salt Preservatives.

Science.gov (United States)

1983-08-01

were measured on small clear bending specimens of longleaf pine sapwood treated with three wateroorne salt preservative systems. Preservative...wood, but the results of past research in this area (appendix I: Literature) are inconsistent and inconclusive, particularly at high loadings of...pine sapwood either air or kiln dried after treatment to retentions from 0.25 to 2.5 lb/ft3. ACA has no effect on MOR. but CCA-type preservatives

Probabilistic representation of duration of load effects in timber structures

DEFF Research Database (Denmark)

Svensson, Staffan

2011-01-01

Reliability analysis of structures for the purpose of code calibration or reliability verification of specific structures requires that the relevant failure modes are represented and analyzed. For structural timber, sustaining a life load, two failure cases for each failure mode have......-based design of timber structures in terms of a modification factor View the MathML source which is multiplied on the short-term resistance of the timber material. The scenario of a beam subject to office space life loads is analyzed and the modification factor View the MathML source is calibrated by using...... to be considered. These two cases are maximum load level exceeding load-carrying capacity and damage accumulation (caused by the load and its duration) leading to failure. The effect of both load intensity and load duration on the capacity of timber has been an area of large interest over the last decades...

Assessing the Sustainability of EU Timber Consumption Trends: Comparing Consumption Scenarios with a Safe Operating Space Scenario for Global and EU Timber Supply

Directory of Open Access Journals (Sweden)

Meghan O’Brien

2017-12-01

Full Text Available The growing demand for wood to meet EU renewable energy targets has increasingly come under scrutiny for potentially increasing EU import dependence and inducing land use change abroad, with associated impacts on the climate and biodiversity. This article builds on research accounting for levels of primary timber consumption—e.g., toward forest footprints—and developing reference values for benchmarking sustainability—e.g., toward land use targets—in order to improve systemic monitoring of timber and forest use. Specifically, it looks at future trends to assess how current EU policy may impact forests at an EU and global scale. Future demand scenarios are based on projections derived and adapted from the literature to depict developments under different scenario assumptions. Results reveal that by 2030, EU consumption levels on a per capita basis are estimated to be increasingly disproportionate compared to the rest of the world. EU consumption scenarios based on meeting around a 40% share of the EU renewable energy targets with timber would overshoot both the EU and global reference value range for sustainable supply capacities in 2030. Overall, findings support literature pointing to an increased risk of problem shifting relating to both how much and where timber needed for meeting renewable energy targets is sourced. It is argued that a sustainable level of timber consumption should be characterized by balance between supply (what the forest can provide on a sustainable basis and demand (how much is used on a per capita basis, considering the concept of fair shares. To this end, future research should close data gaps, increase methodological robustness and address the socio-political legitimacy of the safe operating space concept towards targets in the future. A re-use of timber within the economy should be supported to increase supply options.

Alaska’s timber harvest and forest products industry, 2011

Science.gov (United States)

Erik C. Berg; Charles B. Gale; Todd A. Morgan; Allen M. Brackley; Charles E. Keegan; Susan J. Alexander; Glenn A. Christensen; Chelsea P. McIver; Micah G. Scudder

2014-01-01

This report traces the flow of timber harvested in Alaska during calendar year 2011, describes the composition and operations of the state’s primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, export, sales of primary wood products,...

Pre-Stressing Timber-Based Plate Tensegrity Structures

DEFF Research Database (Denmark)

Falk, Andreas; Kirkegaard, Poul Henning

2012-01-01

Tensile structures occur in numerous varieties utilising combinations of tension and compression. Introducing structural plates in the basic tensegrity unit and tensegric assemblies varies the range of feasible topologies and provides the structural system with an integrated surface. The present...... paper considers the concept of plate tensegrity based on CLT plates (cross-laminated timber). It combines the principles of tensegrity with the principles of plate shells and is characterised by a plate shell stabilised by struts and cables. The paper deals with material aspects and robustness of timber...

Statistical Analysis of Data for Timber Strengths

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2003-01-01

Statistical analyses are performed for material strength parameters from a large number of specimens of structural timber. Non-parametric statistical analysis and fits have been investigated for the following distribution types: Normal, Lognormal, 2 parameter Weibull and 3-parameter Weibull...... fits to the data available, especially if tail fits are used whereas the Log Normal distribution generally gives a poor fit and larger coefficients of variation, especially if tail fits are used. The implications on the reliability level of typical structural elements and on partial safety factors...... for timber are investigated....

36 CFR 13.485 - Subsistence use of timber and plant material.

Science.gov (United States)

2010-07-01

... cutting of standing timber by local rural residents for appropriate subsistence uses, such as firewood or... materials for subsistence uses, and the noncommerical gathering of dead or downed timber for firewood, shall...

Automated radiofrequency-based US measurement of common carotid intima-media thickness in RA patients treated with synthetic vs synthetic and biologic DMARDs.

Science.gov (United States)

Naredo, Esperanza; Möller, Ingrid; Corrales, Alfonso; Bong, David A; Cobo-Ibáñez, Tatiana; Corominas, Hector; Garcia-Vivar, Ma Luz; Macarrón, Pilar; Navio, Teresa; Richi, Patricia; Iagnocco, Annamaria; Garrido, Jesús; Martínez-Hernández, David

2013-02-01

To compare the carotid intima-media thickness (IMT) assessed with automated radiofrequency-based US in RA patients treated with synthetic vs synthetic and biologic DMARDs and controls. Ninety-four RA patients and 94 sex- and age-matched controls were prospectively recruited at seven centres. Cardiovascular (CV) risk factors and co-morbidities, RA characteristics and therapy were recorded. Common carotid artery (CCA)-IMT was assessed in RA patients and controls with automated radiofrequency-based US by the same investigator at each centre. Forty-five (47.9%) RA patients had been treated with synthetic DMARDs and 49 (52.1%) with synthetic and biologic DMARDs. There were no significant differences between the RA patients and controls in demographics, CV co-morbidities and CV disease. There were significantly more smokers among RA patients treated with synthetic and biologic DMARDs (P = 0.036). Disease duration and duration of CS and synthetic DMARD therapy was significantly longer in RA patients treated with synthetic and biologic DMARDs (P radiofrequency-based measurement of CCA-IMT can discriminate between RA patients treated with synthetic DMARDs vs RA patients treated with synthetic and biologic DMARDs.

Robustness Analysis of a Wide-Span Timber Structure with Ductile Behaviour

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Cizmar, D.

2010-01-01

This paper considers robustness evaluation of a wide span timber truss structure where the ductile behavior is taken into account. The robustness analysis is based on a structural reliability framework used on a simplified mechanical system modelling a timber truss system. A measure of ductile...... behaviour is introduced and for different values of this measure the robustness indices are estimated. The results indicate that the robustness of a timber truss system can be increased by taking the ductile behavior into....

36 CFR 294.24 - Timber cutting, sale, or removal in Idaho Roadless Areas.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Timber cutting, sale, or..., DEPARTMENT OF AGRICULTURE SPECIAL AREAS Idaho Roadless Area Management § 294.24 Timber cutting, sale, or removal in Idaho Roadless Areas. (a) Wild Land Recreation. The cutting, sale, or removal of timber is...

125 Timber Dealers' Perception of their Knowledge of the Forest ...

African Journals Online (AJOL)

Nekky Umera

Abstract. This study investigated timber dealers' knowledge of the forest law and regulations in Uyo Senatorial District. Five timber markets were selected through two-stage sampling. Data were collected from 238 traders in the selected markets using structured questionnaires and subjected to descriptive and inferential ...

The Dendrochronological Dating of Timber Crossings in West Jutland, Denmark

DEFF Research Database (Denmark)

Daly, Aoife

2006-01-01

The dendrochronological analyses of a large number of timbers from two sites are described. Nybro causeway in west Jutland, Denmark, which was built in the 8th century AD, consists of numerous phases, identifiable due to the large number of dendrochronologically dated timbers, of which many had...

North Dakota timber industry: an assessment of timber product output and use, 2009

Science.gov (United States)

David E. Haugen; Robert A. Harsel

2013-01-01

Presents recent North Dakota forest industry trends; production and receipts of industrial roundwood; and production of saw logs and other products in 2009. Logging residue generated from timber harvest operations is reported, as well as wood and bark residue generated at primary wood-using mills and disposition of mill residues.

A CCA+ICA based model for multi-task brain imaging data fusion and its application to schizophrenia.

Science.gov (United States)

Sui, Jing; Adali, Tülay; Pearlson, Godfrey; Yang, Honghui; Sponheim, Scott R; White, Tonya; Calhoun, Vince D

2010-05-15

Collection of multiple-task brain imaging data from the same subject has now become common practice in medical imaging studies. In this paper, we propose a simple yet effective model, "CCA+ICA", as a powerful tool for multi-task data fusion. This joint blind source separation (BSS) model takes advantage of two multivariate methods: canonical correlation analysis and independent component analysis, to achieve both high estimation accuracy and to provide the correct connection between two datasets in which sources can have either common or distinct between-dataset correlation. In both simulated and real fMRI applications, we compare the proposed scheme with other joint BSS models and examine the different modeling assumptions. The contrast images of two tasks: sensorimotor (SM) and Sternberg working memory (SB), derived from a general linear model (GLM), were chosen to contribute real multi-task fMRI data, both of which were collected from 50 schizophrenia patients and 50 healthy controls. When examining the relationship with duration of illness, CCA+ICA revealed a significant negative correlation with temporal lobe activation. Furthermore, CCA+ICA located sensorimotor cortex as the group-discriminative regions for both tasks and identified the superior temporal gyrus in SM and prefrontal cortex in SB as task-specific group-discriminative brain networks. In summary, we compared the new approach to some competitive methods with different assumptions, and found consistent results regarding each of their hypotheses on connecting the two tasks. Such an approach fills a gap in existing multivariate methods for identifying biomarkers from brain imaging data.

Implementing CITES regulations for timber.

Science.gov (United States)

Blundell, Arthur G

2007-03-01

Foresters are currently confronted with a new challenge. For the first time a commonly traded timber species has been listed on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). At the 12th Conference of the Parties in November 2002, countries voted 68 to 30 to place the premier timber species of Latin America, big-leaf mahogany (Swietenia macrophylla King [Meliaceae]), on CITES Appendix II. Under Appendix II regulations, trade in mahogany requires that exporting countries verify that each shipment was legally obtained and that its harvest was non-detrimental to the survival of the species. Unfortunately, implementation has been weak, in part because countries have yet to develop a common, pragmatic, cost-effective system to make the legal and non-detriment findings. This paper recommends what such a system might include.

System Reliability of Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2010-01-01

elements, alternate load path(s) etc. in the structural design. In general these characteristics can have a positive influence on system reliability of a structure however, in Eurocodes ductility is only awarded for concrete and steel structures but not for timber structures. It is well......-know that structural systems can redistribute internal forces due to ductility of a connection, i.e. some additional loads can be carried by the structure. The same effect is also possible for reinforced concrete structures and structures of steel. However, for timber structures codes do not award that ductility......For reduction of the risk of collapse in the event of loss of structural element(s), a structural engineer may take necessary steps to design a collapse-resistant structure that is insensitive to accidental circumstances e.g. by incorporating characteristics like redundancy, ties, ductility, key...

Dowelled structural connections in laminated bamboo and timber

OpenAIRE

Reynolds, Thomas Peter; Sharma, Bhavna; Harries, Kent; Ramage, Michael Hector

2015-01-01

Structural sections of laminated bamboo can be connected using methods common in timber engineering, however the different material properties of timber and laminated bamboo suggest that the behaviour of connections in the two materials would not be the same. This study investigates the dowelled connection, in which a connector is passed through a hole in the material, and load is resisted by shear in the connector and embedment into the surrounding material. Steel dowels were used in a conne...

Assessment of demand and supply of timber products in Benue ...

African Journals Online (AJOL)

This study examines demand and supply of timber products in Benue State Nigeria with a view to highlighting the responsiveness of forest policy implementation. The scope of the study lies on plantation establishment targets and costs for 1999 to 2003, actual plantation establishment, timber supply and demand from ...

Guidelines for the on-site assessment of historic timber structures

NARCIS (Netherlands)

Cruz, H.; Yeomans, D.; Tsakanika, E.; Macchioni, N.; Jorissen, A.J.M.; Touza, M.; Mannucci, M.; Lourenco, P.B.

2014-01-01

In the scope of COST IE0601-WoodCulther (http://www.woodculther.org) it was agreed to produce Guidelines for the Assessment of Historic Timber Structures, covering the principles and possible approaches for the safety assessment of old timber structures of historical relevance, that could be used as

Influence Of Density On The Durabilities Of Three Ghanaian Timbers ...

African Journals Online (AJOL)

Review of factors influencing wood durability shows although density varies depending on trunk position, its role appears controversial for many timber species. Thus, for the first time, the influence of density on the durability of three Ghanaian timbers (Nauclea diderrichii (de Wild.) Merr., Nesogordonia papaverifera (A. Chev ...

Protection of mechanized timberings on beds dangerous for mine impacts

Energy Technology Data Exchange (ETDEWEB)

Budirsky, S

1982-01-01

In some stoping faces on beds which are dangerous for mine impacts, mechanized timbering is successfully used which is not equipped with protection from the effect of these dynamic phenomena. This generated the idea that in the indicated conditions, mechanized timbering may not be equipped with protective devices against dynamic loads. Theoretical studies have shown that the effects of mine impacts depends on the total energy of the impact, distance of this stoping face from the epicenter of the impact, as well as the capacity of the rock massif to transmit and absorb energy of the mine impact. This means that the effect of the mine impact under different conditions is not the same, the mine impacts of lower energy under definite conditions can result in greater damages to the mechanized timbering than mine impact with higher energy. It is believed that the effect of absorption of energy of the mine impact depends on the method of control of the roofing in the stoping face, the presence of hydraulic fill quarantees absorption of up to 80% of its energy. The experience of working beds which are dangerous for mine impacts in the upper Silesia coal basin indicated that the designs of the mechanized timbering, especially shield, in which the stands are not rigidly connected to the roof timber, during operation on beds with thickness 2.5-4 m withstand mine impacts with energy 10/sup 7/ J without significant disorders (mine impacts with this energy occur very frequently . For energy of mine impact of 108 J (impacts with this energy are observed comparatively rarely), the mechanized timberings are considerably damaged.

Long-term behaviour of timber structures in torrent control

Science.gov (United States)

Rickli, Christian; Graf, Frank

2014-05-01

Timber is widely used for protection measures in torrent control. However, life span of woody constructions such as timber check dams is limited due to fungal decay. However, only sparse scientific information is available on the long-term behaviour of timber structures and the colonisation with decay fungi. Related to this, in practice a controversial discussion has been going on if either Norway Spruce (Picea abies) or Silver Fir (Abies alba) is more enduring and if bark removal increases resistance against fungal decay. In order to going into this matter a series of 15 timber check dams built in 1996 has been monitored. The constructions were alternatively realised with Norway Spruce and Silver Fir, half of them each with remaining and removed bark, respectively. The scientific investigations included the documentation of colonisation with rot fungi and the identification of decayed zones with a simple practical approach as well as based on drilling resistance. Colonisation by decay fungi started three years after construction (e.g. Gloeophyllum sepiarium), detecting two years later first parts with reduced wood resistance. Sixteen years after construction decay was found on all check dams but two. Wood quality was markedly better in watered sections compared to the occasionally dry lateral abutment sections. Taking the whole check dams into consideration, slightly more decay was detected in Norway Spruce compared to logs in Silver Fir and both the practical approach and the drilling resistance measurement yielded in more defects on logs without bark. However, due to limited number of replications and fungal data, it was not possible to statistically verify these results. Statistical analysis was restricted to the drilling resistance data and fruit-bodies of decay fungi of the uppermost log of each check dam. Based on this limited analysis significant differences in the effect on the drilling resistance were found for watered sections and lateral abutments

Evaluation in vitro of the infection times of engorged females of Rhipicephalus (Boophilus microplus by the entomopathogenic nematode Steinernema glaseri CCA strain Avaliação in vitro dos tempos de infecção de fêmeas ingurgitadas de Rhipicephalus (Boophilus microplus pelo nematoide entomopatogênico Steinernema glaseri estirpe CCA

Directory of Open Access Journals (Sweden)

Leandro Barbiéri de Carvalho

2010-04-01

Full Text Available Studies have shown that ticks are susceptible to infection by entomopathogenic nematodes. These studies indicate different susceptibilities of ticks to infection by these fungi, depending on the tick species, development phase, entomopathogenic nematodes species and strains and the time the ticks are exposed to them. Usually this period ranges from 24 to 72 hours. The aim of this study was to evaluate the infection times in vitro of engorged Rhipicephalus (Boophilus microplus females by the entomopathogenic nematodes Steinernema glaseri CCA strain, by analysis of the ticks' biological parameters. The results show that a 2-hour exposure time was sufficient for the engorged R. microplus females to be infected by S. glaseri CCA, but that a minimum exposure time of 24 hours was necessary to generate treatment efficacy above 90%.Os carrapatos são susceptíveis à infecção por nematoides entomopatogênicos. Essa susceptibilidade diverge quanto às espécies de carrapato estudadas, à fase evolutiva, às espécies e estirpes dos nematoides e ao tempo ao qual os carrapatos ficam expostos a estes. O presente trabalho teve como objetivo avaliar os tempos de infecção in vitro de fêmeas ingurgitadas de Rhipicephalus (Boophilus microplus pelo nematoide entomopatogênico Steinernema glaseri estirpe CCA, pela análise dos parâmetros biológicos do carrapato. Os resultados obtidos demonstraram que um período de duas horas de exposição foi suficiente para que fêmeas ingurgitadas de R. microplus fossem infectadas por S. glaseri CCA e que um período de exposição mínimo de 24h foi necessário para que houvesse infecção de fêmeas ingurgitadas de R. microplus por S. glaseri estirpe CCA, capaz de gerar, in vitro, eficácia no tratamento superior a 90%.

Moment Capacity of Timber Reinforced with Punched Metal Plate Fasteners

DEFF Research Database (Denmark)

Nielsen, Jacob; Ellegaard, Peter

When designing timber trusses it is often found that the cross section controlling the dimensions of the top chord is located at a joint with a moment peak. However, the timber volume affected by the moment peak is rather limited and by embedding a punched metal plate in this area a reinforcement...... of the section is obtained, resulting in a more economic truss design. In order to develop design methods for sections with plate reinforcement, bending tests have been made. The timber is Swedish spruce of strength class K-18(S8) and K-24(S10) with a thickness of 45 mm. The punched metal plate is from Gang...

Timber - Material of the Future - Examples of Small Wooden Architectural Structures

Science.gov (United States)

Żmijewki, Tomasz; Wojtowicz-Jankowska, Dorota

2017-10-01

The aim of this article is to present various types of wood-based products, classified as engineered timber, while specifying the implications of their structural properties for their forms. Timber is used as a construction material due to its fire resistance, good structural characteristics and insulating properties. The advent of new technologies of wood processing and wood-based materials production has converted timber into a high-tech material, thus encouraging the architects to consider it ever more often in their projects. As wooden technologies overcome constraints, timber begins to compete with steel and concrete. The design characteristics of new wood-based products allow wooden structures to be higher, have larger spans, and more diverse forms than ever. Wood-based materials include materials made of solid wood, veneers, strand, and wood which, due to its inferior quality, would otherwise be unfit for constructions. Elements and layers of these products are glued using different kinds of strong and water-resistant adhesives. The article presents the history of development of new wood technologies, discussing increasingly popular wood-based materials such as glued laminated timber, cross-laminated timber, or structural composite lumber. The paper analyses their technical and fire-resistance properties, and points to ecological aspect, as factors contributing to the growing popularity of these materials. Finally, the timber’s characteristics are contrasted with those of steel and concrete. The article lists examples of wooden objects representing the so-called small architecture structures from across Europe. They illustrate the potential, the uniqueness and the versatility that wood-based materials offer for constructors and architects. All these features form sufficient grounds for stating that timber truly is a construction material of the 21st century.

Timber Elements: Traditional and Modern Strengthening Techniques

Directory of Open Access Journals (Sweden)

Raluca Hohan

2010-01-01

Full Text Available The main idea of this paper is to analyse the means for the rehabilitation of our cultural heritage timber structures. Several methods together with their application techniques are described, and also, the reasons for what these strengthening operations become imminent at a point. First of all, the necessity of the timber structural elements strengthening is explained through a short presentation of the factors which are degrading the material. Then, certain precautions and strengthening procedures are presented, all involving the usage of traditional materials like wood, metal, or concrete, and of modern materials like fiber reinforced polymeric composite.

South Dakota timber industry: an assessment of timber product output and use, 2009

Science.gov (United States)

Ronald J. Piva; Gregory J. Josten

2013-01-01

Presents recent South Dakota forest industry trends; production and receipts of industrial roundwood; and production of saw logs, veneer logs, pulpwood, and other products in 2009. Logging residue generated from timber harvest operations is reported, as well as wood and bark residue generated at primary wood-using mills and disposition of mill residues.

T-section glulam timber bridge modules : modeling and performance

Science.gov (United States)

Paul A. Morgan; Steven E. Taylor; Michael A. Ritter; John M. Franklin

1999-01-01

This paper describes the design, modeling, and testing of two portable timber bridges, each consisting of two noninterconnected longitudinal glued-laminated timber (glulam) deck panels 1.8 m (6 ft) wide. One bridge is 12.2 m (40 ft) long while the other bridge is 10.7 m (35 ft) long. The deck panels are fabricated in a unique double-tee cross section. The bridges...

Tree-mendous Timber Evaluation

Science.gov (United States)

2004-01-01

Funded and administered by NASA, the Affiliated Research Center (ARC) program transfers geospatial technologies from the Space Agency and participating universities to commercial companies, non-profit and trade organizations, and tribal governments. The origins of the ARC program date back to 1988, when NASA's Stennis Space Center initiated the Visiting Investigator Program to bring industry closer to spatial information technologies. The success of this trial program led to an expansion into the ARC program, whose goal is to enhance competitiveness of U.S. industries through more efficient use of remote sensing and related technologies. NASA's ARC program served as the foundation for the development of International Hardwood Resources, which then grew into Falcon Informatics with the acquisition of a technology from a European software company and a change of business models. Doylestown, Pennsylvania-based Falcon Informatics is now a world-leading information services company that combines in-depth timber industry experience with state-of-the-art software to serve the needs of national governments, international paper companies, and timber-investment management organizations.

Predicting moisture state of timber members in a continuously varying climate

DEFF Research Database (Denmark)

Svensson, Staffan; Turk, Goran; Hozjan, Tomaz

2011-01-01

A prerequisite for a sensible estimate of moisture induced stresses in timber members is an accurate prediction of the members’ moisture states during their service life. There are, however, an infinite number of possible moisture states for an arbitrary timber member in a natural varying climate...... the realizations were made, are based on a fully coupled transport model including a model for the influential sorption hysteresis of wood. A format containing required information suitable for assessing the “moisture” action on timber members is proposed. In addition it is illustrated how a model of high...

Reliability Analysis of Timber Structures through NDT Data Upgrading

DEFF Research Database (Denmark)

Sousa, Hélder; Sørensen, John Dalsgaard; Kirkegaard, Poul Henning

The first part of this document presents, in chapter 2, a description of timber characteristics and common used NDT and MDT for timber elements. Stochastic models for timber properties and damage accumulation models are also referred. According to timber’s properties a framework is proposed...... for a safety reassessment procedure. For that purpose a theoretical background for structural reliability assessment including probabilistic concepts for structural systems and stochastic models are given in chapter 3. System models, both series and parallel systems, are presented as well as methods...... for robustness are dealt in chapter 5. The second part of this document begins in chapter 6, where a practical application of the premise definitions and methodologies is given through the implementation of upgraded models with NDT and MDT data. Structural life-cycle is, therefore, assessed and reliability...

Appropriateness of Probit-9 in development of quarantine treatments for timber and timber commodities

Science.gov (United States)

Marcus Schortemeyer; Ken Thomas; Robert A. Haack; Adnan Uzunovic; Kelli Hoover; Jack A. Simpson; Cheryl A. Grgurinovic

2011-01-01

Following the increasing international phasing out of methyl bromide for quarantine purposes, the development of alternative treatments for timber pests becomes imperative. The international accreditation of new quarantine treatments requires verification standards that give confidence in the effectiveness of a treatment. Probit-9 mortality is a standard for treatment...

A Feasibility Study on Timber Damage Detection Using Piezoceramic-Transducer-Enabled Active Sensing

Directory of Open Access Journals (Sweden)

Jicheng Zhang

2018-05-01

Full Text Available In recent years, piezoelectric-based transducers and technologies have made significant progress towards structural health monitoring and damage evaluation for various metal and concrete structures. Timber is still commonly used as a construction material in practical engineering; however, there is a lack of research on the health monitoring of timber-based structures using piezoelectric-based transducers and methods. This paper conducts a feasibility study on timber damage detection using surface-mounted piezoelectric patches, which enable the stress-wave-based active sensing approach. Typical damage modes in timber frame structures, such as surface cracks and holes, were investigated in this study. In the active sensing approach, one piezoceramic transducer is used as an actuator to generate stress waves, which propagate along the surface of the timber structure, and other piezoceramic transducers function as sensors to detect the propagating stress waves. Defects, such as a crack or a hole, induce additional attenuation to the propagating stress wave. Based on this attenuation, the proposed method can detect the defects using the wavelet-packet-based damage index, demonstrating its implementation potential for real-time timber damage detection.

Agroforestry systems of timber species and cacao: survival and growth during the early stages

Directory of Open Access Journals (Sweden)

Wilmer Espinoza

2013-08-01

Full Text Available In recent times, increased emphasis has been placed on diversifying the types of trees to shade cacao (Theobromacacao L. and to achieve additional services. Agroforestry systems that include profitable and native timber trees are a viable alternative but it is necessary to understand the growth characteristics of these species under different environmental conditions. Thus, timber tree species selection should be based on plant responses to biotic and abiotic factors. The aims of this study were (1 to evaluate growth rates and leaf area indices of the four commercial timber species: Cordia thaisiana, Cedrela odorata, Swietenia macrophylla and Tabebuia rosea in conjunction with incidence of insect attacks and (2 to compare growth rates of four Venezuelan Criollo cacao cultivars planted under the shade of these four timber species during the first 36 months after establishment. Parameters monitored in timber trees were: survival rates, growth rates expressed as height and diameter at breast height and leaf area index. In the four Cacao cultivars: height and basal diameter. C. thaisiana and C. odorata had the fastest growth and the highest survival rates. Growth rates of timber trees will depend on their susceptibility to insect attacks as well as to total leaf area. All cacao cultivars showed higher growth rates under the shade of C. odorata. Growth rates of timber trees and cacao cultivars suggest that combinations of cacao and timber trees are a feasible agroforestry strategy in Venezuela.

Field investigations of historic covered timber bridges in the USA

Science.gov (United States)

James Wacker; Travis Hosteng; Brent. Phares

2012-01-01

The Federal Highway Administration is sponsoring a comprehensive research program on Historic Covered Timber Bridges in the USA. This national program's main purpose is to develop improved methods to preserve, rehabililate, and restore the timber bridge trusses that were developed during the early 1800s, and in many cases are still in service today. The overall...

Projecting national forest inventories for the 2000 RPA timber assessment.

Science.gov (United States)

John R. Mills; Xiaoping. Zhou

2003-01-01

National forest inventories were projected in a study that was part of the 2000 USDA Forest Service Resource Planning Act (RPA) timber assessment. This paper includes an overview of the status and structure of timber inventory of the National Forest System and presents 50-year projections under several scenarios. To examine a range of possible outcomes, results are...

Nondestructive assessment of timber bridges using a vibration-based method

Science.gov (United States)

Xiping Wang; James P. Wacker; Robert J. Ross; Brian K. Brashaw

2005-01-01

This paper describes an effort to develop a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the natural frequency of single-span timber bridges in the laboratory and field. An analytical model based on simple beam theory was proposed to represent the relationship...

Robustness of Long Span Reciprocal Timber Structures

DEFF Research Database (Denmark)

Balfroid, Nathalie; Kirkegaard, Poul Henning

2011-01-01

engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper makes a discussion of such robustness issues related to the future development of reciprocal timber structures. The paper concludes that these kind of structures can have...... a potential as long span timber structures in real projects if they are carefully designed with respect to the overall robustness strategies.......Robustness of structural systems has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. The interest has also been facilitated due to recently severe structural failures...

Global timber trade pattern: the cards have changed

OpenAIRE

Roda Jean-Marc; Rohana Abd Rahman; Ismariah Ahmad; Lim Hin Fui; Mohd Parid Mamat

2011-01-01

Since the 1960s, the global timber trade has gradually evolved from a South-North trade to a South-South trade, with an acceleration of the phenomenon in the mid 1990s. Nowadays, Asia consumes more than 70% (in round wood equivalent) of the forest products originating from the tropics. Africa becomes the new frontier for the supplies of wood material for Asian giants, which now source raw wood from all over the world. Since the mid 1990s, the dynamics of the tropical timber trade have been in...

Intelligent CAMAC crate controller with CC-A2 functionality and VICbus interface

International Nuclear Information System (INIS)

Erven, W.; Holzer, J.; Kopp, H.; Loevenich, H.W.; Meiling, W.; Zwoll, K.; Bovier, J.; Re, G.; Worm, F.

1992-01-01

This paper reports that for nuclear physics experiments at the Julich Cooler Synchrotron COSY a data acquisition system is under development. With this background, and in order to enhance existing CAMAC systems, an intelligent CAMAC crate controller with CC-A2 functionality was developed. The main enhancement is the replacement of the Branch Highway with a new standard of inter-crate connection: the VICbus. The other highlights are: optional use of a Motorola 68030 microprocessor as CAMAC list-processor and optimization of CAMAC blocktransfers, optional Ethernet or Cheapernet connection. This controller is commercially available from CES, Geneva and called VCC 2117

Responses of timber rattlesnakes to fire: Lessons from two prescribed burns

Science.gov (United States)

Steven J. Beaupre; Lara E. Douglas

2012-01-01

Timber rattlesnakes (Crotalus horridus) are excellent model organisms for understanding the effects of large scale habitat manipulations because of their low-energy lifestyle, rapid response to changes in resource environment, uniform diet (small mammals), and simple behaviors. We present two case studies that illustrate interactions between timber...

Elementary and advanced modelling of the splitting strength of timber connections

NARCIS (Netherlands)

Schoenmakers, J.C.M.D.

2008-01-01

The load-bearing capacity of a timber member loaded perpendicular-to-grain by a connection is governed by either the embedment strength, the bending yield strength of the steel fasteners, or the splitting strength of the timber. Only coarse models for predicting the splitting strength are

Timber resource statistics for non-federal forest land in northwest Oregon.

Science.gov (United States)

Donald R. Gedney; Patricia M. Bassett; Mary A. Mei

1986-01-01

This report summarizes a 1986 timber resource inventory of the non-Federal forest land in the 10 counties (Clackamas, Clatsop, Columbia, Hood River, Marion, Multnomah , Polk, Tillamook, Washington, and Yamhill) in northwest Oregon. Detailed tables of forest area, timber volume, growth, mortality, and harvest are presented.

Can Structural Timber Foster Short Procurement Chains within Mediterranean Forests? A Research Case in Sardinia

Directory of Open Access Journals (Sweden)

Massimo Fragiacomo

2015-06-01

Full Text Available Background and Purpose: The aim of this paper is to present the idea of a timber short procurement chain as a means to provide an increased value to Mediterranean forests. It is based on the evidence that timber buildings are increasingly used for a number of reasons including sustainability, the speed of erection, and excellent structural and seismic performance. However, most of the timber currently used around the Mediterranean is imported from outside this area. Materials and Methods: The idea is to use the best part of the tree to produce timber boards, while all the remaining part of the tree including the production waste is used for energy production. Important issues to address are the generally low mechanical properties of locally-grown timber such as maritime pine in Sardinia, which would make some wood-based products such as glue-laminated timber not technically viable. Cross-laminated timber panels are a possible solution to this problem because this wood-based product is manufactured in such a way that even with low-quality timber boards it is possible to obtain a medium quality panel. The panel is made of layers of timber boards with the adjacent layers glued under pressure at a right angle. Another issue is the need to grade the local timber, for which a number of specimens must be tested to destruction in order to identify a visual or a machine-stress grading procedure. Last but not least, the panels must be tested to destruction to correlate their mechanical properties to the properties of the boards. Results: The preliminary mechanical tests carried out on Sardinia maritime pine confirm that the material is low-grade because it is characterized by large knots and a significant grain deviation. Nevertheless, when used in the cross-laminated panels, the properties are significantly improved due to the layout of the panel which reduces the influence of defects in the boards on the mechanical properties of the panel. Conclusions

Robustness Analyses of Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Hald, Frederik

2013-01-01

The robustness of structural systems has obtained a renewed interest arising from a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. In order to minimise the likelihood of such disproportionate structural failures, many mo...... with respect to robustness of timber structures and will discuss the consequences of such robustness issues related to the future development of timber structures.......The robustness of structural systems has obtained a renewed interest arising from a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. In order to minimise the likelihood of such disproportionate structural failures, many...... modern building codes consider the need for the robustness of structures and provide strategies and methods to obtain robustness. Therefore, a structural engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper summaries issues...

Radiation technique in density and strength testing of coniferous structural timber

International Nuclear Information System (INIS)

Dzbenski, W.; Krzosek, S.

1998-01-01

The control process of intermediate and final wood products manufacturing is more and more frequently assisted by flow detectors. In radiation devices cesium isotope 137 Cs is replaced by less harmful americium 241 Am. Americium 241 Am was used in the measuring device made in The Academy of Mining and Metallurgy in Cracow. The device was applied in Warsaw Agricultural University (SGGW) in research on Polish structural timber. Negative influence of anatomical defects (knots, compression wood, resinasis, slope of grain, decay) was estimated by gammascopy method. Botanical species (pine, spruce), position in a stem (sapwood, heartwood), anatomical direction (radial, tangential) and moisture content were taken into account. The method of determination a critical place in timber were density is the lowest value (what is an obligatory criterion of stress graded structural timber according to EN standards) was developed. The practical implementation of the method can be reached when sawmills producing structural timber (especially for export) will be more interested in using miniaturized isotope densitometers. (author)

Timber drying kilns using solar energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-15

The objective of this project was to research the potential for solar kilns for drying timber in tropical countries (Guyana, Honduras and Belize) and produce a manual which will provide the knowledge necessary to build and operate a solar kiln. The main output of the project is the manual Solar Heated Timber Drying Kilns - a Manual on their Design and Operation. The manual covers:- background information; selection of construction materials; methods of kiln construction; kiln operation and maintenance procedure. The manual has been designed to provide the necessary knowledge and confidence to build and operate a solar kiln, and ultimately benefit from an improved product. Specifically, the manual will benefit small building construction units, furniture and joinery manufacturers and sawmill operators in developing and developed countries worldwide. (author)

Timber resource statistics for the Yakataga inventory unit, Alaska, 1976.

Science.gov (United States)

Willem W.S. van Hees

1985-01-01

Statistics on forest area, total gross and net timber volumes, and annual net growth and mortality are presented from the 1976 timber inventory of the Yakataga unit, Alaska. Timberland area is estimated at 209.3 thousand acres (84.7 thousand ha), net growing stock volume at 917.1 million cubic feet (26.0 million m3), and annual net growth and...

Simplified Analytical Model for a Queen-Post Covered Timber Bridge

Science.gov (United States)

F Fanous; D. Rammer; T. Wipf

2013-01-01

During the 19th century, the economic material to build bridges was timber due to its abundant availability, cost, and ease of construction. Many of the well-known timber bridge types are the Burr arch, Town lattice, Howe, Queen and King type of trusses. This paper summarizes an investigation that was sponsored by the Federal Highway Administration and the USDA Forest...

Metal loss from treated wood products in contact with municipal solid waste landfill leachate

Energy Technology Data Exchange (ETDEWEB)

Dubey, Brajesh [Department of Environmental Health, PO Box 70682, East Tennessee State University, Johnson City, TN 37614 (United States); Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States); Townsend, Timothy, E-mail: ttown@ufl.edu [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States); Solo-Gabriele, Helena [Department of Civil, Architectural and Environmental Engineering, University of Miami, Coral Gables, FL 33124-0630 (United States)

2010-03-15

The research presented in this paper evaluates the potential impact of municipal solid waste (MSW) landfill leachate quality on the loss of metals from discarded treated wood during disposal. The loss of arsenic (As), chromium (Cr), copper (Cu), and boron (B) from several types of pressure-treated wood (CCA: chromated copper arsenate, ACQ: alkaline copper quaternary, CBA: copper boron azole, and DOT: disodium octaborate tetrahydrate) using leachate collected from 26 MSW landfills in Florida was examined. The toxicity characteristic leaching procedure (TCLP), the synthetic precipitation leaching procedure (SPLP), and California's waste extraction test (WET) were also performed. The results suggested that loss of preservative components was influenced by leachate chemistry. Copper loss from CCA-, ACQ- and CBA-treated wood was similar in magnitude when in contact with landfill leachates compared to synthetic TCLP and SPLP solutions. Ammonia was found as one of the major parameters influencing the leaching of Cu from treated wood when leached with MSW landfill leachates. The results suggest that disposal of ACQ- and CBA-treated wood in substantial quantity in MSW landfills may elevate the Cu concentration in the leachate; this could be of potential concern, especially for a bioreactor MSW landfill in which relatively higher ammonia concentrations in leachate have been reported in recent literature. For the As, Cr and B the concentrations observed with the landfill leachate as the leaching solutions were over a range from some sample showing the concentrations below and some showing above the observed value from corresponding SPLP and TCLP tests. In general the WET test showed the highest concentrations.

A Probabilistic Approach for Robustness Evaluation of Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

of Structures and a probabilistic modelling of the timber material proposed in the Probabilistic Model Code (PMC) of the Joint Committee on Structural Safety (JCSS). Due to the framework in the Danish Code the timber structure has to be evaluated with respect to the following criteria where at least one shall...... to criteria a) and b) the timber frame structure has one column with a reliability index a bit lower than an assumed target level. By removal three columns one by one no significant extensive failure of the entire structure or significant parts of it are obatined. Therefore the structure can be considered......A probabilistic based robustness analysis has been performed for a glulam frame structure supporting the roof over the main court in a Norwegian sports centre. The robustness analysis is based on the framework for robustness analysis introduced in the Danish Code of Practice for the Safety...

A new shock wave assisted wood preservative injection system

Science.gov (United States)

Rao, K. S.; Ravikumar, G.; Lai, Ram; Jagadeesh, G.

Preservative treatment of many tropical hard woods and bamboo pose severe problem. A number of wood preservatives (chemical formulations toxic to wood decay/ destroying organisms like fungi, wood destroying termites, marine borers etc.) and wood impregnating techniques are currently in use for improving bio resistance of timber and bamboo and thereby enhancing service life for different end uses. How ever, some species of tropical hardwoods and many species of bamboo are difficult to treat, posing technical problems. In this paper we report preliminary results of treatment of bamboo with a novel Shockwave assisted injection treatment. Samples (30×2.5×1.00 cm) of an Indian species of bamboo Dendrocalamus strictus prepared from defect free culms of dry bamboo are placed in the driven section of a vertical shock tube filled with the 4Coppepr-Chrome-Arsenic(CCA) preservative solution.The bamboo samples are subjected to repeated shock wave loading (3 shots) with typical over pressures of 30 bar. The results from the study indicate excellent penetration and retention of CCA preservative in bamboo samples. The method itself is much faster compared to the conventional methods like pressure treatment or hot and cold process.

Computer software to estimate timber harvesting system production, cost, and revenue

Science.gov (United States)

Dr. John E. Baumgras; Dr. Chris B. LeDoux

1992-01-01

Large variations in timber harvesting cost and revenue can result from the differences between harvesting systems, the variable attributes of harvesting sites and timber stands, or changing product markets. Consequently, system and site specific estimates of production rates and costs are required to improve estimates of harvesting revenue. This paper describes...

36 CFR 223.195 - Procedures for identifying and marking unprocessed timber.

Science.gov (United States)

2010-07-01

... procedures required herein. (f) Waiver of branding requirements. Regional Foresters may waive the branding... individual timber sale basis, all or a portion of the branding requirements pursuant to paragraph (c)(2) of...) Regions 5 and 6. On an individual timber sale basis, the branding requirement pursuant to paragraph (c)(2...

Timber resources of Ohio

Science.gov (United States)

Neal P. Kingsley; Carl E. Mayer

1970-01-01

Under the authority of the McSweeney-McNary Forest Research Act of May 22, 1928, and subsequent amendments, the Forest Service, U. S. Department of Agriculture, conducts a series of continuing forest surveys of all states to provide up-to-date information about the forest resources of the Nation. A resurvey of the timber resources of Ohio was made in 1966 and 1967 by...

Timber resource statistics for non-Federal forest land in west-central Oregon.

Science.gov (United States)

Donald R. Gedney; Patricia M. Bassett; Mary A. Mei

1987-01-01

This report summarizes a 1985-86 timber resource inventory of the non-Federal forest land in the four counties (Benton, Lane, Lincoln, and Linn) in west-central Oregon. Detailed tables of forest area, timber volume, growth, mortality, and harvest are presented.

Development of a smart timber bridge girder with fiber optic sensors

Science.gov (United States)

James Wacker; Ursula Deza; Brent M. Phares; Terry J. Wipf

2010-01-01

Past timber bridge evaluation and maintenance efforts in the USA have principally focused on the internal integrity of timber components using various non-destructive evaluation tools to supplement visual inspection data. This project is part of a comprehensive effort to develop smart structure concepts for improving the long-term performance, maintenance, and...

Timber Curtain: Designing with material capabilities

DEFF Research Database (Denmark)

Lahmy, Maya; Larsen, Niels Martin

2015-01-01

of the generative phase to fabrication of the artefact. Brought together by various conceptual and structural elements the Timber Curtain forms a 4.5 x 2.5 x 0.5 m construct of assembled wood components, digitally crafted through advanced production techniques. Concerned with materiality and processing of the wood......Timber Curtain explores relations between digital precision and material indeterminacy. It is an installation engaging spatially through its presence as a 1:1 architectural component as well as it is exploring novel technologies in the architectural design process from the very beginning...... an associative digital model that could gather and compute in put from material behaviour and out put manufacturing data was scripted. This method enables material capacity to be pushed to the limit of its performance allowing novel sensuous and structural qualities to emerge. The method is developed with use...

Characteristics of Timbers Dried Using Kiln Drying and Radio Frequency-Vacuum Drying Systems

OpenAIRE

Rabidin Zairul Amin; Seng Gan Kee; Wahab Mohd Jamil Abdul

2017-01-01

Heavy hardwoods are difficult-to-dry timbers as they are prone to checking and internal stresses when dried using a conventional kiln drying system. These timbers are usually dried naturally to reach 15% to 19% moisture content with an acceptable defects. Besides long drying time, timbers at these moisture contents are not suitable for indoor applications since they will further dry and causing, for example, jointing and lamination failures. Drying to a lower moisture content could only be ac...

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.

Market of innovative timber products in Europe and Serbia and their contribution to climate change mitigation

Directory of Open Access Journals (Sweden)

Sretenović Predrag

2014-01-01

Full Text Available The paper shows results of researching the market of glued laminated timber as the most frequent innovative timber product in constructing timber framed residential facilities in Europe and Serbia. The research included the development of production, consumption and trade flows for the most significant countries in the European Union and Serbia. Additionally, the paper gives characteristics of this innovative timber product regarding dimensions, allowed deviations of dimensions defined in adequate European standard, wood species it is made of and fire resistance. The last part of the paper shows results of econometric modeling of the impact of building timber-framed houses on the consumption of glued laminated timber in Austria as one of the countries belonging to the group of the largest consumers of this innovative timber product in Europe. Taking into consideration that the substitution of classic building materials, primarily concrete, steel and aluminum, with glued laminated timber in residential construction contributes to the reduction of carbon-dioxide emission and climate change mitigation, research results of the effects of such substitution are presented in the last chapter in this paper. [Projekat Ministarstva nauke Republike Srbije, br. III43007: Istraživanje klimatskih promena na životnu sredinu: praćenje uticaja, adaptacija i ublažavanje

Dowel-type fastener connections in timber structures subjected to short-term loading

DEFF Research Database (Denmark)

Lauritzen Jensen, J.

Design of dowel-type fastener connections in framed timber structures usually involves a two-step analysis: determination of the distribution of the sectional forces, and design of the eccentrically loaded connections. This report presents an integrated model for design of framed timber structures...

Cut and Run: Illegal Logging and Timber Trade in the Tropics | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

Illegal logging and trade in timber is a major cause of forest degradation in the world ... But controlling this global problem is not a simple matter of enacting new laws ... practices in the logging industry and timber trade of four tropical countries.

Service life assessment of timber highway bridges in USA climate zones

Science.gov (United States)

James P. Wacker; Brian K. Brashaw; Thomas G. Williamson; P. David Jones; Matthew S. Smith; Travis K. Hosteng; David L. Strahl; Lola E. Coombe; V.J. Gopu

2014-01-01

As engineers begin to estimate life-cycle costs and sustainable design approaches for timber bridges, there is a need for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This...

Timber bridge evaluation : a global nondestructive approach using impact generated FRFs

Science.gov (United States)

Angus Morison; C.D. Van Karsen; H.A. Evensen; J.B. Ligon; J.R. Erickson; R.J. Ross; J.W. Forsman

2002-01-01

Bridges require periodic inspections to ensure the safety of those using the structure. A visual inspection has historically been the most common form of investigation for timber bridges. This poses many problems when inspecting bridge timbers since often the damage is internal, leaving no visible signs of decay on the surface. Localized nondestructive evaluation (NDE...

Time-of-Flight Adjustment Procedure for Acoustic Measurements in Structural Timber

Science.gov (United States)

Danbiel F. Llana; Guillermo Iñiguez-Gonzalez; Francisco Arriaga; Xiping Wang

2016-01-01

The effect of timber length on time-of-flight acoustic longitudinal measurements was investigated on the structural timber of four Spanish species: radiata pine (Pinus radiata D. Don), Scots pine (Pinus sylvestris L.), laricio pine (Pinus nigra Arn.), and maritime pine (Pinus pinaster Ait.). Time-of-flight longitudinal measurements were conducted on 120 specimens of...

Balancing Conservation and Economic Sustainability: The Future of the Amazon Timber Industry

Science.gov (United States)

Merry, Frank; Soares-Filho, Britaldo; Nepstad, Daniel; Amacher, Gregory; Rodrigues, Hermann

2009-09-01

Logging has been a much maligned feature of frontier development in the Amazon. Most discussions ignore the fact that logging can be part of a renewable, environmentally benign, and broadly equitable economic activity in these remote places. We estimate there to be some 4.5 ± 1.35 billion m3 of commercial timber volume in the Brazilian Amazon today, of which 1.2 billion m3 is currently profitable to harvest, with a total potential stumpage value of 15.4 billion. A successful forest sector in the Brazilian Amazon will integrate timber harvesting on private lands and on unprotected and unsettled government lands with timber concessions on public lands. If a legal, productive, timber industry can be established outside of protected areas, it will deliver environmental benefits in synergy with those provided by the region’s network of protected areas, the latter of which we estimate to have an opportunity cost from lost timber revenues of 2.3 billion over 30 years. Indeed, on all land accessible to harvesting, the timber industry could produce an average of more than 16 million m3 per year over a 30-year harvest cycle—entirely outside of current protected areas—providing 4.8 billion in returns to landowners and generating 1.8 billion in sawnwood sales tax revenue. This level of harvest could be profitably complemented with an additional 10% from logging concessions on National Forests. This advance, however, should be realized only through widespread adoption of reduced impact logging techniques.

Multi-objective room acoustic optimization of timber folded plate structure

DEFF Research Database (Denmark)

Skov, Rasmus; Parigi, Dario; Damkilde, Lars

2017-01-01

This paper investigates the application of multi-objective optimization in the design of timber folded plate structures in the scope of the architectural design process. Considering contrasting objectives of structural displacement, early decay time (EDT), clarity (C50) and sound strength (G......), the methodology applied in two benchmarks tests, encompasses both structural and acoustic performance when determining folding characteristics and directionality of surfaces in a timber folded plate structure....

Eleventh-century shift in timber procurement areas for the great houses of Chaco Canyon.

Science.gov (United States)

Guiterman, Christopher H; Swetnam, Thomas W; Dean, Jeffrey S

2016-02-02

An enduring mystery from the great houses of Chaco Canyon is the origin of more than 240,000 construction timbers. We evaluate probable timber procurement areas for seven great houses by applying tree-ring width-based sourcing to a set of 170 timbers. To our knowledge, this is the first use of tree rings to assess timber origins in the southwestern United States. We found that the Chuska and Zuni Mountains (>75 km distant) were the most likely sources, accounting for 70% of timbers. Most notably, procurement areas changed through time. Before 1020 Common Era (CE) nearly all timbers originated from the Zunis (a previously unrecognized source), but by 1060 CE the Chuskas eclipsed the Zuni area in total wood imports. This shift occurred at the onset of Chaco florescence in the 11th century, a time with substantial expansion of existing great houses and the addition of seven new great houses in the Chaco Core area. It also coincides with the proliferation of Chuskan stone tools and pottery in the archaeological record of Chaco Canyon, further underscoring the link between land use and occupation in the Chuska area and the peak of great house construction. Our findings, based on the most temporally specific and replicated evidence of Chacoan resource procurement obtained to date, corroborate the long-standing but recently challenged interpretation that large numbers of timbers were harvested and transported from distant mountain ranges to build the great houses at Chaco Canyon.

The Economics of Timber Supply: An Analytical Synthesis of Modeling Approaches

Science.gov (United States)

David N. Wear; Peter J. Parks

1994-01-01

The joint supply of timber and other services from forest environments plays a central role in most forest land debates. This paper defines a general conceptual model of timber supply that provides the context for discussing both individual harvest choice and aggregate supply models. While the structure and breadth of these models has developed considerably over the...

Evaluation of the AJCC 8th Edition Staging System for Pathologically Versus Clinically Staged Intrahepatic Cholangiocarcinoma (iCCA): a Time to Revisit a Dogma? A Surveillance, Epidemiology, and End Results (SEER) Analysis.

Science.gov (United States)

Kamarajah, Sivesh K

2018-03-07

Recently, the AJCC has released its 8th edition changes to the staging system for intrahepatic cholangiocarcinoma (iCCA). This study sought to validate the proposed changes to the 8th edition of AJCC system for T and N classification of iCCA using a population-based data set. Using the Surveillance, Epidemiology, and End Results (SEER) database (1998-2013), patients undergoing resection or non-surgical management for non-metastatic iCCA were identified. Overall survival was estimated using the Kaplan-Meier method and compared using log-rank tests. Concordance indices (c-indices) calculated from Cox proportional hazards models were calculated to evaluate discriminatory power. The study included 2630 patients resected (37%) or non-surgically managed (63%) for iCCA. Nodal staging was performed in 56%, of whom 31% had positive nodes. For all patients with iCCA, the median 5-year survival by AJCC T classification for T1a, T1b, T2, T3, and T4 was 32, 21, 14, 10, and 10 months, respectively (p < 0.001). The concordance index for the staging system was 0.57 for all patients, 0.62 for those who underwent resection, and 0.54 for patients who did not undergo resection. In summary, the new AJCC 8th edition staging system is comparable to the 7th edition and valid in stratifying patients with iCCA. However, the performance of the staging system is better in patients undergoing surgical resection than those undergoing non-surgical management. These findings further highlight the need for improved accuracy of radiological imaging in clinically staging patients to guide prognosis.

Probabilistic Modeling of Graded Timber Material Properties

DEFF Research Database (Denmark)

Faber, M. H.; Köhler, J.; Sørensen, John Dalsgaard

2004-01-01

The probabilistic modeling of timber material characteristics is considered with special emphasis to the modeling of the effect of different quality control and selection procedures used as means for quality grading in the production line. It is shown how statistical models may be established...... on the basis of the same type of information which is normally collected as a part of the quality control procedures and furthermore, how the efficiency of different control procedures may be quantified and compared. The tail behavior of the probability distributions of timber material characteristics plays...... such that they may readily be applied in structural reliability analysis and their format appears to be appropriate for codification purposes of quality control and selection for grading procedures....

Timber designers' manual

CERN Document Server

Ozelton, E C

2008-01-01

This major reference manual covers both overall and detail design of structural timber, including aspects such as shear deflection, creep, dynamic and lateral stability considerations for flexural members.Available for the first time in paperback, the Third Edition was substantially revised to take account of the many changes since the previous edition was published in 1984. It is based on British Standard BS 5268-2: 2002, which brought design concepts closer to European practice and Eurocode 5.Features of the Third Edition include:* information on bolt values including

Successful and unsuccessful attempts to resolve caribou management and timber harvesting issues in west central Alberta

Directory of Open Access Journals (Sweden)

David Hervieux

1996-01-01

Full Text Available Research studies of woodland caribou in west central Alberta began in 1979 in response to proposed timber harvesting on their winter ranges. Using results from initial studies, timber harvest guidelines were developed. A recent review of these guidelines, and the assumptions on which they were based, has resulted in a renegotiation by government and industry of timber harvesting on caribou range in west central Alberta. Caribou range in west central Alberta overlaps many jurisdictional boundaries: federal and provincial lands, four Forest Management Agreement Areas, three Alberta Land and Forest Service Regions and two Alberta Fish and Wildlife Service Regions. This jurisdictional complexity in combination with other factors such as total allocation of the timber resources, high levels of petroleum, natural gas and coal extraction activities, a high level of concern by public groups for caribou conservation and recent understanding of woodland caribou needs for abundant space has made resolution of caribou/timber harvest conflicts exceedingly slow and often relatively unproductive. This paper reviews 10 years of trying to resolve conflicts between timber harvesting and caribou conservation through meetings, committees, integrated resource planning, policy papers and public consultation. We describe what might be learned by other jurisdictions that are trying to resolve similar caribou/timber harvesting issues. We conclude with an overview of recent timber harvest planning initiatives on caribou range in west central Alberta.

Parametric Evaluation of Racking Performance of Platform Timber Framed Walls

OpenAIRE

Dhonju, R..; D’Amico, B..; Kermani, A..; Porteous, J..; Zhang, B..

2017-01-01

This paper provides a quantitative assessment of the racking performance of partially anchored timber framed walls, based on experimental tests. A total of 17 timber framed wall specimens, constructed from a combination of materials under different load configurations, were tested. The experimental study was designed toexamine the influence of a range of geometrical parameters, such as fastener size and spacings, wall length, arrangement of studs and horizontal members, as well as the effect ...

Timber resource statistics for Oregon.

Science.gov (United States)

Sally Campbell; Paul Dunham; David. Azuma

2004-01-01

This report is a summary of timber resource statistics for all ownerships in Oregon. Data were collected as part of several statewide multiresource inventories, including those conducted by the Pacific Northwest Region (Region 6) on National Forest System lands in Oregon, by the Bureau of Land Management (BLM) on BLM lands in western Oregon, and by the Pacific...

Evaluation of recycled timber members

Science.gov (United States)

Douglas R. Rammer

1999-01-01

An experimental study was conducted to evaluate the residual shear capacity of large Douglas-fir timbers used in a military facility in Ardeen Hills, MN. A S-point and 4-point bending test was used to determine the effects of checks and splits on the shear strength capacity. Experimental results are compared to past shear and flexural studies.

Timber management opportunities in Pennsylvania

Science.gov (United States)

Henry H. Webster

1960-01-01

The Pennsylvania Department of Forests and Waters serves the people in managing state forest lands and in helping private owners manage their forest lands. To produce more timber from Pennsylvania forests, the Department applies many different forestry practices. But the more effort it spends in one direction, the less it can spend in others. So the Department must...

A view from the top: US enrichment Corp.'s William H. Timbers, Jr

International Nuclear Information System (INIS)

Giltenan, E.

1993-01-01

Nick Timbers took over as the first Transition Manager of the US Enrichment Corporation upon its founding last July 1st. Although USEC is not involved in negotiating the HEU deal, the fledgling company will be in charge of actually buying and selling the resulting LEU. Whenever the deal is finally signed. After the politics and haggling are over, it will be up to Nick Timbers to make the deal work on the global uranium market. The view from USEC is resolute. No matter what shape the final HEU deal takes, Nick Timbers promises that USEC will remain a competitive supplier of enrichment services. Timbers pledges that any extra costs associated with the HEU deal will not be passed on to customers. He took time out from his recent busy schedule to share his thoughts on HEU and its aftermath

Reliability based Robustness of Timber Structures through NDT Data Updating

DEFF Research Database (Denmark)

Sousa, Hélder S.; Sørensen, John Dalsgaard; Kirkegaard, Poul Henning

2011-01-01

This work presents a framework for reliability-based assessment of timber structures / members using data gathered from non-destructive test results. These results are used for modeling an update of the mechanical characteristics of timber, using Bayesian methods. Results gathered from ultrasound...... of the structure, thus, being possible to evaluate reliability based in time dependent factors, as well to categorize that structure in terms of robustness. For exemplification of the underlined concepts, three different types of structures are studied....

Friction welding of wood – A fast, adhesive-free bonding technology for prefabricated elements in timber construction

OpenAIRE

Hahn, Benjamin; Hatt, Fred

2013-01-01

Up to now chemical adhesives based on polyurethane are used for the assembling of timber planks to large-scale structural elements, in particular cross-laminated timber panels (CLT), which opened new possibilities for architects and engineers in timber construction. The use of these adhesives still implicates, beside others, concerns about their impact on health and environment during application as well for later disposal. In order to overcome the geometrical limitations of timber by maintai...

Silver mirror reaction as an approach to construct a durable, robust superhydrophobic surface of bamboo timber with high conductivity

Energy Technology Data Exchange (ETDEWEB)

Jin, Chunde; Li, Jingpeng [School of Engineering, Zhejiang Agricultural and Forestry University, Lin’an 311300 (China); Key Laboratory of Wood Science and Technology, Zhejiang Province (China); Han, Shenjie; Wang, Jin; Yao, Qiufang [School of Engineering, Zhejiang Agricultural and Forestry University, Lin’an 311300 (China); Sun, Qingfeng, E-mail: zafuqfsun@163.com [School of Engineering, Zhejiang Agricultural and Forestry University, Lin’an 311300 (China); Key Laboratory of Wood Science and Technology, Zhejiang Province (China)

2015-06-25

Highlights: • Ag NPs were deposited onto the surface of bamboo timber by silver mirror reaction. • The Ag NPs made the intrinsic insulating bamboo timber have a high conductivity. • The modified surfaces displayed superhydrophobicity even for corrosive solutions. - Abstract: Silver nanoparticles (Ag NPs) were successfully in situ deposited onto the surface of the bamboo timber through a simple silver mirror reaction. Scanning electron microscopy (SEM) images showed that the surface of the bamboo timber was densely covered with the uniform Ag NPs, which made the intrinsic insulating bamboo timber conductive. With further modification by fluoroalkylsilane (FAS), the Ag NPs-covered bamboo timber showed superhydrophobicity with the water contact angle (WCA) of 155°. Simultaneously, the modified bamboo timber displayed a durable and robust superhydrophobic property even under corrosive solutions including acidic, alkali and NaCl solutions with different molar concentrations. Especially in harsh conditions of boiling water or intense water stirring, the modified bamboo timber remained superhydrophobicity and high conductivity.

Robustness Assessment of Spatial Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning

2012-01-01

Robustness of structural systems has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. In order to minimise the likelihood of such disproportionate structural failures many modern buildi...... to robustness of spatial timber structures and will discuss the consequences of such robustness issues related to the future development of timber structures.......Robustness of structural systems has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. In order to minimise the likelihood of such disproportionate structural failures many modern building...... codes consider the need for robustness of structures and provide strategies and methods to obtain robustness. Therefore a structural engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper summaries issues with respect...

Historic timber roof structures

OpenAIRE

Magina, Miguel Jorge

2013-01-01

Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Estruturas e Geotecnia This dissertation covers the study of historic timber roof structures in Transylvania area - Romania, the structures type, its elements and connection variety between them. Procedures to study a structure of this category are approached. It is also referred semi and non-destructive tests that can be done to better understand the present wood characteristics, and potential reparation or strengthening...

SOFRA and RPA: two views of the future of southern timber supply.

Science.gov (United States)

Darius Adams; John Mills; Ralph Alig; Richard. Haynes

2005-01-01

Two recent studies provide alternative views of the current state and future prospects of southern forests and timber supply: the Southern Forest Resource Assessment (SOFRA) and the Fifth Resources Planning Act Timber Assessment (RPA). Using apparently comparable data but different models and methods, the studies portray futures that in some aspects are quite similar...

On the use of NDT Data for Reliability-Based Assessment of Existing Timber Structures

DEFF Research Database (Denmark)

Sousa, Hélder S.; Sørensen, John Dalsgaard; Kirkegaard, Poul Henning

2013-01-01

The objective of this paper is to address the possibilities of using non-destructive testing (NDT) data for updating information and obtaining adequate characterization of the reliability level of existing timber structures and, also, for assessing the evolution in time of performance...... of these structures when exposed to deterioration. By improving the knowledge upon the mechanical properties of timber, better and more substantiated decisions after a reliability safety assessment are aimed at. Bayesian methods are used to update the mechanical properties of timber and reliability assessment......, and information of NDT is also used to calibrate these models. The proposed approach is used for reliability assessment of different structural timber systems. Reliability of the structural system is assessed regarding the failure consequences of individual elements defined as key elements which were determined...

Theory of timber connections with slender dowel type fasteners

DEFF Research Database (Denmark)

Svensson, Staffan; Munch-Andersen, Jørgen

2018-01-01

A theory on the lateral load-carrying capacity of timber connections with slender fasteners is presented. The base of the theory is the coupled mechanical phenomena acting in the connection, while the wood and the slender fastener deform and yield prior to failure. The objective is to derive...... a sufficient description of actions and responses which have determining influence on the load-carrying capacity of timber connections with slender fasteners. Model assumptions are discussed and made, but simplifications are left out. Even so, simple mathematical equations describing the lateral capacity......-carrying capacity of the tested connections....

Using TPO data to estimate timber demand in support of planning on the Tongass National Forest

Science.gov (United States)

Jean M. Daniels; Michael D. Paruszkiewicz; Susan J. Alexander

2015-01-01

Projections of Alaska timber products output, the derived demand for logs, lumber, residues, and niche products, and timber harvest by owner are developed by using a trend-based analysis. This is the fifth such analysis performed since 1990 to assist planners in meeting statutory requirements for estimating planning cycle demand for timber from the Tongass National...

Strategies for Sustainable Development of Non-Timber Forest Products in Senegal

OpenAIRE

Sene, Abdou

2001-01-01

In recent years, forests have been increasingly recognized as rich reservoirs for many valuable biological resources. As a result of the devastation caused by drought, clearing land for agriculture, and overexploitation of timber, there has been a growing interest in non-timber forest products (NTFPs). The Senegal Forestry Action Plan, designed to ensure sustainable forest management, stresses the importance of identifying the constraints to and opportunities for sustainable development of no...

The effects of population growth on timber management and inventories in Virginia

Science.gov (United States)

David N. Wear; Rei Liu; J. Michael Foreman; Raymond M. Sheffield

1999-01-01

Expanding human populations may have important effects on the availability of timber from private lands in the South. To examine the effects of development on timber supply, the authors compared the density of populations and various site variables with expert opinions on the future location of commercial timberland for a study site in Virginia. Population density is a...

Timber resource statistics for the San Joaquin and southern California resource areas.

Science.gov (United States)

Bruce Hiserote; Joel Moen; Charles L. Bolsinger

1986-01-01

This report is one of five that provide timber resource statistics for 57 of the 58 counties in California (San Francisco is excluded). This report presents statistics from a 1982-84 inventory of the timber resources of Alpine, Amador, Calaveras, Fresno, Imperial, Inyo, Kern, Kings, Los Angeles, Madera, Mariposa, Merced, Mono, Orange, Riverside, San Bernardino, San...

Dynamic programming for optimization of timber production and grazing in ponderosa pine

Science.gov (United States)

Kurt H. Riitters; J. Douglas Brodie; David W. Hann

1982-01-01

Dynamic programming procedures are presented for optimizing thinning and rotation of even-aged ponderosa pine by using the four descriptors: age, basal area, number of trees, and time since thinning. Because both timber yield and grazing yield are functions of stand density, the two outputs-forage and timber-can both be optimized. The soil expectation values for single...

Structural attributes of two old-growth Cross Timbers stands in western Arkansas

Science.gov (United States)

Don C. Bragg; David W. Stahle; K. Chris Cerny

2012-01-01

Comprised of largely non-commercial, xeric, oak-dominated forests, the Cross Timbers in Arkansas have been heavily altered over the last two centuries, and thus only scattered parcels of old-growth timber remain. We inventoried and mapped two such stands on Fort Chaffee Military Training Center in Sebastian County, Arkansas. The west-facing Christmas Knob site is...

Nondestructive assessment of single-span timber bridges using a vibration- based method

Science.gov (United States)

Xiping Wang; James P. Wacker; Angus M. Morison; John W. Forsman; John R. Erickson; Robert J. Ross

2005-01-01

This paper describes an effort to develop a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the natural frequency of single-span timber bridges in the laboratory and field. An analytical model based on simple beam theory was proposed to represent the relationship...

77 FR 2508 - Rogue River-Siskiyou National Forest, Powers Ranger District, Coos County, OR; Eden Ridge Timber...

Science.gov (United States)

2012-01-18

... Plan, page C-39). Specifically for the Eden Ridge Timber Sales project, Needs include: Improvement of... District, Coos County, OR; Eden Ridge Timber Sales AGENCY: Forest Service, USDA. ACTION: Corrected Notice of Intent to prepare an environmental impact statement for the Eden Ridge Timber Sales. The original...

Statistical Analysis of Data for Timber Strengths

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Hoffmeyer, P.

Statistical analyses are performed for material strength parameters from approximately 6700 specimens of structural timber. Non-parametric statistical analyses and fits to the following distributions types have been investigated: Normal, Lognormal, 2 parameter Weibull and 3-parameter Weibull...

Splitting behaviour of timber loaded perpendicular to the grain by punched metal plates

NARCIS (Netherlands)

Schoenmakers, J.C.M.; Jorissen, A.J.M.; Leijten, A.J.M.; Aratake, S. xx

2008-01-01

Nowadays, prefabricated timber trusses are widely used as load-bearing roof structures. The majority of these trusses are produced with punched metal plates (PMP) to connect two or more timber elements of the same thickness, see Figure 2. In these structures sufficient overlap is required to prevent

Framework for Robustness Assessment of Timber Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2011-01-01

This paper presents a theoretical framework for the design and analysis of robustness of timber structures. This is actualized by a more4 frequent use of advanced types of timber structures with limited redundancy and serious consequences in the case of failure. Combined with increased requirements...... to efficiency in design and execution followed by increased risk of human errors has made the need of requirements to robustness of new structures essential. Further, the collapse of the Ballerup Super Arena, the bad Reichenhall Ice-Arena and a number of other structural systems during the last 10 years has...... increased the interest in robustness. Typically, modern structural design codes require that ‘the consequence of damages to structures should not be disproportional to the causes of the damages’. However, although the importance of robustness for structural design is widely recognized, the code requirements...

Self-extinguishment of cross-laminated timber

NARCIS (Netherlands)

Crielaard, R.; van de Kuilen, J.W.G.; Terwel, K.C.; Ravenshorst, G.J.P.; Steenbakkers, P.; Breunesse, A.

2016-01-01

Cross-laminated timber, or CLT, is receiving attention for its potential use in tall buildings. As a combustible material, one of the challenges for the construction of these buildings is the fire risk that results from its use in the structure. Unprotected CLT can burn along with the fuel load

Understanding Loss Deductions for Timber

Science.gov (United States)

John Greene; Michael Jacobson

1998-01-01

Forestland owners whose timber has been destroyed may be eligible to take a deduction for the loss on their federal income tax. The loss must be physical in nature and caused by an identifiable event or combination of events that has run its course. There are two types of losses from natural events. Casualty losses are sudden, unexpected, and unusual - as from a fire...

Field performance of timber bridges. 7, Connell Lake stress-laminated deck bridge

Science.gov (United States)

L. E. Hislop; M. A. Ritter

The Connell Lake bridge was constructed in early 1991 on the Tongass National Forest, Alaska, as a demonstration bridge under the Timber Bridge Initiative. The bridge is a stress-laminated deck structure with an approximate 36-ft length and 18-ft width and is the first known stress-laminated timber bridge constructed in Alaska. Performance of the bridge was monitored...

Space-time modeling of timber prices

Science.gov (United States)

Mo Zhou; Joseph Buongriorno

2006-01-01

A space-time econometric model was developed for pine sawtimber timber prices of 21 geographically contiguous regions in the southern United States. The correlations between prices in neighboring regions helped predict future prices. The impulse response analysis showed that although southern pine sawtimber markets were not globally integrated, local supply and demand...

Velocity and uniformity of air circulation in conventional kilns for sawn timber

Directory of Open Access Journals (Sweden)

Kolin Branko

2012-01-01

Full Text Available This paper presents the results of a research of velocity of air circulation in the conventional kiln drying of sawn timber and its influence on the uniformity of final moisture content. The data showed that the air velocity (between 0.8 - 1.2 m•s -1 is significantly lower than the one that is optimal for timber drying of coniferous species (3 - 4 m•s-1. This results in a reduction in the capacity of installations for drying, increased energy (thermal and electrical consumption and thereby increase in the cost of drying. The correlation between the speed of air circulation and the final MC of timber due to prolonged drying was not established. Recommendations that should eliminate the identified deficiencies are also given.

High-frequency and microwave heating as a pretreatment to kiln drying of hollowed-out timber

International Nuclear Information System (INIS)

Yamada, N.; Okumura, S.; Taniguchi, Y.

2001-01-01

To dry hollowed-out timber without V-shaped drying checks, its inner part should be dried faster than the outer part. The feasibility of high frequency heating and microwave heating as a pretreatment of kiln drying of hollow timber was examined. During high frequency heating, the top and bottom parts of the timber were dried faster than the right and left parts because the central hollow acts as an air-gap. The outer part dried faster than the inner part during microwave heating, probably because of insufficient penetration of microwave energy into the inner part. The uneven heating of hollowed timber was improved by turning the specimen around its axis during high frequency heating and by setting the specimen upright in the microwave oven

Geology, Burnst Timber Creek, west of fifth meridian, Alberta

Energy Technology Data Exchange (ETDEWEB)

1966-01-01

The Burnt Timber Creek map-area lies in the southern Foothills of Alberta and includes a narrow strip of the Front Range of the Rocky Mts. along its western edge. The area may be divided into 3 principal structural units, underlain from west to east by the McConnell, Burnt Timber, and Fallentimber thrusts, respectively. McConnell thrust underlies the eastern edge of the mountains. Subsidiary folding and faulting are locally evident in the Paleozoic strata above the thrust. Beneath the McConnell thrust, Mesozoic and Paleozoic strata of the Burnt Timber thrust sheet are strongly overturned in the Panther anticline. The axis of this anticline trends northwest. A culmination along it, in the vicinity of Sheep Creek, deforms the McConnel thrust as well. A total of 16 wells have been drilled to date in 4 separate groups. Each group has revealed the presence of gas and 8 of the wells have been capped as potential gas producers. The reservoir rocks are of Mississippian and Devonian age. Shell Panther River No. 1 well (5-19-30-10W5) is remarkable in having tested at about 86% hydrogen sulfide.

Timber resource statistics for all forest land, except national forests, in eastern Oregon.

Science.gov (United States)

Donald R. Gedney; Patricia M. Bassett; Mary A. Mei

1989-01-01

This report summarizes a 1987 timber resource inventory of all forest land, except National Forests, in the 17 counties (Baker, Crook, Deschutes, Gilliam, Grant, Harney, Jefferson, Klamath, Lake, Malheur, Morrow, Sherman, Umatilla, Union, Wallowa, Wasco, and Wheeler Counties) in eastern Oregon. Detailed tables of forest area, timber volume, growth, mortality, and...

36 CFR 223.6 - Cutting and removal of timber in free-use areas.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Cutting and removal of timber... OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER General Provisions § 223.6 Cutting... or designated by forest officers may be cut and removed for personal use for domestic purposes...

Pocket Checklists of Indonesian timber trees

NARCIS (Netherlands)

Prawira, Soewanda A.; Tantra, I.G.M.; Whitmore, T.C.

1984-01-01

Indonesia as yet does not have a comprehensive account of the forest trees which reach timber size (35 cm dbh = 14 inch or 105 cm gbh = 42 inch). A project has been started in August 1983 by the Botany Section of the Forest Research Institute in Bogor, Indonesia, to prepare pocket checklists of the

Live-load performance evaluation of historic covered timber bridges in the United States

Science.gov (United States)

Junwon Seo; Travis K. Hosteng; Brent M. Phares; James P. Wacker

2015-01-01

The National Historic Covered Bridge Preservation Program (NHCBP), sponsored by the Federal Highway Administration (FHWA), was established to preserve the covered timber bridge structures that were constructed in the early 1800s. Today, many of the approximately 880 covered timber bridges still in existence in the United States are closed to vehicular traffic;...

Compressive capacity perpendicular to grain of fully supported timber beams of Poplar - model comparison

NARCIS (Netherlands)

Leijten, A.J.M.; Haddad, Y.M.

2015-01-01

In timber frame structures, for both residential and multi-storey purposes, timber elements are loaded perpendicular to grain. In the past, structural design code calculations were based on pre-set permissible strength values, applying empirical models with obscure background. Modern ultimate limit

Mexican oaks as a potential non-timber resource for Kombucha beverages

OpenAIRE

Vázquez-Cabral, Blanca D.; Moreno-Jiménez, Martha R.; Rocha-Guzmán, Nuria E.; Gallegos-Infante, José A.; González-Herrera, Silvia M.; Gamboa-Gómez, Claudia I.; González-Laredo, Rubén F.

2016-01-01

Abstract: Oaks (Quercus spp.) are some of the world's most important and abundant trees in nearly all temperate forests of the northern hemisphere. There are two diversity centers for this genus: one is in Southeast Asia, and the other is in Mexico. Studies on the use of oak have mainly highlighted its timber applications. However, its non-timber value is still unappreciated. Ethnobotanical tradition shows infusions from Quercus leaves, alone or in combination with other plants, which have an...

Analysis of the connection of the timber-fiber concrete composite structure

Science.gov (United States)

Holý, Milan; Vráblík, Lukáš; Petřík, Vojtěch

2017-09-01

This paper deals with an implementation of the material parameters of the connection to complex models for analysis of the timber-fiber concrete composite structures. The aim of this article is to present a possible way of idealization of the continuous contact model that approximates the actual behavior of timber-fiber reinforced concrete structures. The presented model of the connection was derived from push-out shear tests. It was approved by use of the nonlinear numerical analysis, that it can be achieved a very good compliance between results of numerical simulations and results of the experiments by a suitable choice of the material parameters of the continuous contact. Finally, an application for an analytical calculation of timber-fiber concrete composite structures is developed for the practical use in engineering praxis. The input material parameters for the analytical model was received using data from experiments.

Probabilistic Robustness Analysis of Timber Structures—Results from EU COST Action E55:WG3

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2011-01-01

The present paper outlines results from Working Group 3 (WG3) in the EU COST Action E55—‘Modelling of the performance of timber structures’. The objectives of the project are related to the three main research activities: the identification and modelling of relevant load and environmental exposure...... scenarios, the improvement of knowledge concerning the behaviour of timber structural elements and the development of a generic framework for the assessment of the life-cycle vulnerability and robustness of timber structures....

Development of Hybrid Kiln Drying System with Radio Frequency Heating for the Sugi Heart Timber

OpenAIRE

Piao, Jinji; Fujimoto, Noboru; Yamamoto, Yasushi; Nagata, Soji

2007-01-01

In this study, proper applied stage of the radio-frequency (RF) heating during kiln drying based on the quality concerning the surface checks of the boxed heart timbers was examined. At the stage of the RF heating the moisture contents decreased clearly at the internal parts of timbers. The surface stress of the sugi (Cryptomeria japonica D. Don) boxed heart timber changed into the compression stress by the RF heating in any drying stage. The surface checks increased according to the decrease...

Preparation of chitosan-collagen-alginate composite dressing and its promoting effects on wound healing.

Science.gov (United States)

Xie, Haixia; Chen, Xiuli; Shen, Xianrong; He, Ying; Chen, Wei; Luo, Qun; Ge, Weihong; Yuan, Weihong; Tang, Xue; Hou, Dengyong; Jiang, Dingwen; Wang, Qingrong; Liu, Yuming; Liu, Qiong; Li, Kexian

2018-02-01

The present study aimed to prepare a composite dressing composed of collagen, chitosan, and alginate, which may promote wound healing and prevent from seawater immersion. Chitosan-collagen-alginate (CCA) cushion was prepared by paintcoat and freeze-drying, and it was attached to a polyurethane to compose CCA composite dressing. The swelling, porosity, degradation, and mechanical properties of CCA cushion were evaluated. The effects on wound healing and seawater prevention of CCA composite dressing were tested by rat wound model. Preliminary biosecurity was tested by cytotoxicity and hemocompatibility. The results revealed that CCA cushion had good water absorption and mechanical properties. A higher wound healing ratio was observed in CCA composite dressing treated rats than in gauze or chitosan treated ones. On the fifth day, the healing rates of CCA composite dressing, gauze, and chitosan were 48.49%±1.07%, 28.02%±6.4%, and 38.97%±8.53%, respectively. More fibroblast and intact re-epithelialization were observed in histological images of CCA composite dressing treated rats, and the expressions of EGF, bFGF, TGF-β, and CD31 increased significantly. CCA composite dressing showed no significant cytotoxicity, and favorable hemocompatibility. These results suggested that CCA composite dressing could prevent against seawater immersion and promote wound healing while having a good biosecurity. Copyright © 2017. Published by Elsevier B.V.

Comparative design of the superstructure of timber bridges, using norm np 005 - 2003 and provisions of european standards

Directory of Open Access Journals (Sweden)

Chiotan Corina

2015-12-01

Full Text Available The norms and standards for design of timber bridges, as well as other structures built from this material, were obsolete, design standards that were used dated from 1978 to 1980. The introduction of European Standards has created a new legislative framework in the field of designing and building timber bridges. Currently the design of such constructions use Norm NP 005-2003 and SR EN 1995-1-1: 2004 Eurocode 5: Design of timber structures. Part 1-1: General. Common rules and rules for buildings, SR EN 1995-2: 2005 Eurocode 5: Design of timber structures. Part 2: Bridges, along with their national annexes. The aim of this paper is to analyze the design of the beams for timber bridges in parallel, using on one hand Norm NP 005 - 2003, and on the other hand provisions of European standards. The design requirements for both norms as well as the results of a case study for a structural element of a timber bridge will be presented.

A cut above: building the market for fair trade timber

Energy Technology Data Exchange (ETDEWEB)

MacQueen, Duncan

2008-02-15

Unlike coffee and cotton, timber has yet to become a fair trade commodity. But now its time has come. Rights over forest resources are increasingly ceded to small-scale community forest enterprises (CFEs), as large-scale industrial logging is now largely discredited in the sustainable development context. The fair trade emphasis on just pricing for poorer producers is exactly what CFEs need as incentive to invest in sustainable forest management — and secure environmental and poverty reduction benefits at one stroke. With fair trade timber, CFEs could boost their entrepreneurial capacity using democratic business models with in-built social and environmental responsibility. The Fair Trade Labelling Organizations International and Forest Stewardship Council are exploring the ways and means through a new partnership, but more is needed. Consumers must be made aware of why paying higher prices is key to creating CFE incentives for sustainable forest management and poverty reduction. Time and money are needed for consumer education and installing fair trade timber in producer country forest policies, market segregation and procurement policies at all levels.

Non-timber forest products in Hawaii

Science.gov (United States)

Katie Kamelamela; James B. Friday; Tamara Ticktin; Ashley. Lehman

2015-01-01

Hawaiian forests provide a wide array of non-timber forest products for both traditional and modern uses. Flowers, vines, and ferns are collected for creating garlands or lei for hula dances and parades. Lei made from materials gathered in the forest are made for personal use and sold, especially during graduation times. Bamboo is harvested for structures and for...

Community Based Ecological Monitoring of Non Timber Forest ...

International Development Research Centre (IDRC) Digital Library (Canada)

Community Based Ecological Monitoring of Non Timber Forest Products in the Nilgiri ... This project will allow Keystone Foundation to design, implement and test a ... traders, forest department officials and other stakeholders in the process.

36 CFR 251.14 - Conditions, rules and regulations to govern exercise of timber rights reserved in conveyance to...

Science.gov (United States)

2010-07-01

... timber products and in locating, constructing and using mills, logging roads, railroads, chutes, landings..., and to young growth or to trees left standing. All survey monuments and witness trees shall be preserved. (3) All trees, timber or timber products of species or sizes not specifically reserved which are...

Robustness Analysis of Typologies of Reciprocal Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Parigi, Dario

2013-01-01

to the future development of typologies of reciprocal timber structures. The paper concludes that these kinds of structures can have a potential as long span timber structures in real projects if they are carefully designed with respect to the overall robustness strategies.......Robustness of structural systems has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. In order to minimise the likelihood of such disproportionate structural failures many modern building...... codes consider the need for robustness in structures and provides strategies and methods to obtain robustness. Therefore a structural engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper outlines robustness issues related...

Small wind turbines with timber blades for developing countries: Materials choice, development, installation and experiences

DEFF Research Database (Denmark)

Mishnaevsky, Leon; Freere, Peter; Sinha, Rakesh

2011-01-01

The low cost wind turbines with timber blades represent a good solution for the decentralized energy production in off-grid regions of developing countries. This paper summarizes the results of investigations on the mechanical testing and choice of timber for wind blades, testing of different...... of the blades and turbines. It was further demonstrated that the low cost wind turbines with timber blades represent a promising and viable option for the decentralized energy production in developing countries, which also opens new areas for businesses....

Components interaction in timber framed masonry structures subjected to lateral forces

Directory of Open Access Journals (Sweden)

Andreea DUTU

2012-07-01

Full Text Available Structures with timber framed masonry represent a special typology that is frequently found in Europe and other countries of the world. They are traditional buildings, non-engineered, which showed an unexpected redundancy during earthquakes where reinforced concrete buildings (improperly constructed collapsed. In the paper, aspects regarding the interaction between timber elements and masonry are mainly addressed, that were observed both in experimental studies, but also in the in situ seismic behavior of this type of structure during important earthquakes.

Expanding the scale of forest management: allocating timber harvests in time and space

Science.gov (United States)

Eric J. Gustafson

1996-01-01

This study examined the effect of clustering timber harvest zones and of changing the land use categories of zones (dynamic zoning) over varying temporal and spatial scales. Focusing on the Hoosier National Forest (HNF) in Indiana, USA as a study area, I used a timber harvest allocation model to simulate four management alternatives. In the static zoning alternative,...

Estimating bridge stiffness using a forced-vibration technique for timber bridge health monitoring

Science.gov (United States)

James P. Wacker; Xiping Wang; Brian Brashaw; Robert J. Ross

2006-01-01

This paper describes an effort to refine a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the frequency response of several simple-span, sawn timber beam (with plank deck) bridges located in St. Louis County, Minnesota. Static load deflections were also measured to...

Influence of Compression Stresses on Timber Potentials of ...

African Journals Online (AJOL)

Eucalyptus camaldulensis Denhn in North-Western Nigeria. *1A. ... further research should be carried out on wood in service to study the peculiarities of timber behaviour under actual .... eastern Nigeria, Neem (Azadirachta indica) was found.

The study of carrying capacity of timber slabs with use the finite elements method

Directory of Open Access Journals (Sweden)

Demeshok Vitalii

2017-01-01

Full Text Available In the article, the results of the study of behavior of timber slab under influence of fire with the standard “time-temperature” curve are presented. The finite element method was used for it. For the calculation we constructed a grid models of timber slabs. As a result of solution of the thermal problem was obtained temperature distribution and the graphs of maximum deflection of timber slabs and its slew rate depending on the time of the test. The obtained graphs allow to obtain data on the occurrence of the limit state of loss of bearing capacity by comparing current values of displacements and velocities with the maximum allowable. Analysis of the graphs shows that the criteria limit state of loss of bearing capacity does not occur. Calculation method of evaluating the fire resistance of timber slabs was developed. For it use database about strain-stress state of this slabs in conditions of influence of the fire.

Timber resource of Minnesota's Prairie unit, 1977.

Science.gov (United States)

Jerold T. Hahn; W. Brad Smith

1980-01-01

The fourth inventory of Minnesota's Prairie Unit shows that although commercial forest area decreased 31.7% between 1962 and 1977, growing-stock volume increased 22%. This report gives statistical highlights and contains detailed tables of forest area as well as timber volume, growth, mortality, ownership, and use.

Reinforcement of Bolted Timber Joints Using GFRP Sheets in Poplar and Pine Woods

Directory of Open Access Journals (Sweden)

Mehrab Madhoushi

2013-01-01

Full Text Available Failure in timber structures occurs mainly in crucial points such as joints areas. Therefore, the idea of using composite sheets in timber joints has been intro-duced as a method in order to increase the strength and ductility behaviour of timber joints. This research aims to study the behaviour of bolted joints in poplar and pine woods, which are reinforced by two types of GFRP sheets. A single shear bolted joint consisted of 3 timber members whose length and width were 30 cm in length and 5 cm in width. The thickness of each member was 4 cm for internal part and 2 cm for external part. The employed steel bolt was 10 cm in length and 1 cm in diameter. In this respect, one layer of GFRP sheet was used to be bonded to timber members by using epoxy resin and left between the clamps for 24 hours. They were then kept at room temperature for three weeks. Also the effect of adding a wood veneer on the reinforced joints was investigated. The tensile strength of the reinforced and control samples (un-reinforced joints was measured according to ASTM D5652-92 standard. The results show that the reinforced samples have higher tensile strength compared to that of reinforced joints, although it is not statistically signifcant. Also, two types of sheets infuence the joint behaviour as the reinforced joints display more ductility behaviour.

Mushrooms, trees, and money: value estimates of commercial mushrooms and timber in the pacific northwest.

Science.gov (United States)

Alexander, Susan J; Pilz, David; Weber, Nancy S; Brown, Ed; Rockwell, Victoria A

2002-07-01

Wild edible mushrooms are harvested in the forests of the Pacific Northwest, where both trees and mushrooms grow in the same landscape. Although there has been some discussion about the value of trees and mushrooms individually, little information exists about the joint production of, and value for, these two forest products. Through four case studies, the information needed to determine production and value for three wild mushroom species in different forests of the Pacific Northwest is described, and present values for several different forest management scenarios are presented. The values for timber and for mushrooms are site- and species-specific. On the Olympic Peninsula in Washington, timber is highly valued and chanterelles are a low-value product by weight; timber has a soil expectation value (SEV) 12 to 200 times higher than chanterelles. In south-central Oregon, timber and American matsutake mushrooms have the potential to have about the same SEV. In eastern Oregon, timber is worth 20 to 110 times as much as the morels that grow in the forest. Production economics is concerned with choices about how much and what to produce with what resources. The choices are influenced by changes in technical and economic circumstances. Through our description and analysis of the necessary definitions and assumptions to assess value in joint production of timber and wild mushrooms, we found that values are sensitive to assumptions about changes in forest management, yields for mushrooms and trees, and costs.

Concurring Regulation in European Forest Law; Forest Certification and the New EU Timber Regulation

NARCIS (Netherlands)

Kistenkas, F.H.

2013-01-01

Newly made EU Timber Regulation (EUTR) may prima facie look like competing regulation and an overlap of the existing forest certification schemes of FSC and PEFC as also EUTR combats illegally harvested timber. The novel EUTR, however, is a public law scheme wheras FSC and PEFC are private law

36 CFR 223.193 - Procedures for reporting acquisition and disposition of unprocessed Federal timber.

Science.gov (United States)

2010-07-01

... for the calendar year listing, by company, from whom the timber was acquired; the date of acquisition... certificate stating that: (i) The certifier has read and understands the form; (ii) The certifier is eligible... applicable laws. (b) Transfer of unprocessed National Forest System timber. Each person who transfers to...

Leakage Implications for European Timber Markets from Reducing Deforestation in Developing Countries

Directory of Open Access Journals (Sweden)

Mattias Boman

2012-08-01

Full Text Available Forest management strategies and policies such as REDD (reduced emissions from deforestation and forest degradation may have unintentional implications for forest sectors in countries not targeted by such policies. The success of a policy effort like REDD would result in a significant reduction in deforestation and forest degradation and an ensuing reduction in the supply of natural forest timber production within participating countries. This could in turn result in price increases, inducing a supply response outside project boundaries with possible implications for forest management as well as global carbon emissions. This paper reviews the literature to discern potential timber market implications for countries sourcing wood products from developing countries affected by REDD related conservation efforts. The literature reviewed shows varying degrees of market effects leakage—policy actions in one place creating incentives for third parties to increase timber harvesting elsewhere through the price mechanism—ranging from negligible to substantial. However, wood products in the studies reviewed are dealt with on quite an aggregated scale and are assumed to be more or less perfect substitutes for wood products outside conservation effort boundaries. The review suggests that a thorough mapping of the end-uses of tropical timber is needed to comprehensively analyze impacts on wood-product markets in regions such as Europe from conservation efforts in tropical developing countries. The types of tropical timber expected to be affected, in which applications they are used, which are the most likely substitutes and where they would be sourced, are issues that, along with empirical analysis of supply and demand price elasticities and degree of substitutability, should be investigated when assessing the overall effectiveness of REDD.

Sustainability and Security: Timber Certification in Asia-Pacific Region

Directory of Open Access Journals (Sweden)

Antonina Ivanova

2008-10-01

Full Text Available The expansion of sustainable development initiatives since the 1990’s reflected an emphasis on integrated solutions to economic development, socio-political stability and environmental health in the global community. In the same context the traditional concept of security needed to be open in two directions. First, the notion of security should no longer be applied only to the military realm, but also to the economic, the societal, the environmental, and the political fields. Second, the referent object of the “security” should not be conceptualized solely in terms of the state, but should embrace the individual below the state, and the international system above it. The forests industry timber certification in Asia-Pacific region has been selected as a case study because it is an excellent example to illustrate the links between the sustainable development and the environmental security, including also certain elements of economic security. This article is presenting a critical overview of the forest industry and the status of timber certification globally, with an emphasis on Asia – Pacific countries applying the Systemic Thinking approach. In conclusion, an outlook is presented concerning the future of timber certification and possible impacts on security and sustainable development.

Timber Chips as the Insulation Material for Energy Saving in Prefabricated Offices

Directory of Open Access Journals (Sweden)

Yupeng Wang

2016-06-01

Full Text Available This research demonstrates the feasibility of a roof insulation method for prefabricated offices that uses vinyl packed timber chips to reduce air conditioning loads (hereinafter referred to as AC loads and which also improves indoor thermal comfort. The advantages of the new roof insulation method were revealed through comparing the impacts of four roof types on prefabricated offices. The AC load and indoor thermal comfort (surface temperature and air temperature were evaluated. The disposal of scrap timber discarded from building construction projects is costing money, and is also a waste of natural resources. The assessment of a new roof insulation method with timber chips demonstrates the advanced usage of timber chips, reducing the environmental load in the building construction process. On the other hand, since prefabricated offices have lower thermal storage capacities and are less airtight than RC (reinforced concrete or S (steel structured buildings, the AC load consumption and indoor thermal comfort exacerbation in prefabricated offices is more serious. Especially in summer, a large amount of solar energy absorption from the roof raises the indoor air temperature and significantly increases the cooling load. This research contributes to the environmental design for prefabricated offices, and develops a method for the reuse of wood chips.

Hinged roof timber

Energy Technology Data Exchange (ETDEWEB)

Shestov, P I; Golub, A G; Yefremov, V I

1980-08-07

A hinged roof timer is suggested which includes a beam with prong and loop on the end which have openings in the form of ring slits for the distance wedges and round for the pins. In this case the opening of the distance wedge in the ring is arranged in relation to the opening for the pin closer to the end of the beam, and in the prong, in the opposite order. In order to improve the operating quality by guaranteeing active support of the cantilever roof timber without increasing its overall dimensions for the height of the opening for the distance wedge in the prong and the ring, beams are arranged axisymmetrically to the longitudinal axis.

Commercial lumber, round timbers, and ties

Science.gov (United States)

David E. Kretschmann

2010-01-01

When sawn, a log yields round timber, ties, or lumber of varying quality. This chapter presents a general discussion of grading, standards, and specifications for these commercial products. In a broad sense, commercial lumber is any lumber that is bought or sold in the normal channels of commerce. Commercial lumber may be found in a variety of forms, species, and types...

Clustering Timber Harvests and the Effects of Dynamic Forest Management Policy on Forest Fragmentation

Science.gov (United States)

Eric J. Gustafson

1998-01-01

To integrate multiple uses (mature forest and commodity production) better on forested lands, timber management strategies that cluster harvests have been proposed. One such approach clusters harvest activity in space and time, and rotates timber production zones across the landscape with a long temporal period (dynamic zoning). Dynamic zoning has...

Outgrower timber schemes in KwaZulu-Natal – Do they build sustainable rural livelihoods and what interventions should be made?

CSIR Research Space (South Africa)

Cairns, RI

2000-01-01

Full Text Available Small-scale timber growers access commercial timber markets in KwaZulu-Natal through three mechanisms. These are; highly structured contractual arrangements (SAPPI, Lima and Mondi); membership in commercial forest-owners associations or timber...

26 CFR 1.611-3 - Rules applicable to timber.

Science.gov (United States)

2010-04-01

..., the total quantity under consideration, and the location of the timber in question with reference to... or shares, royalties and rentals, valuation for local or State taxation, partnership accountings...

Trade-offs between carbon stocks and timber recovery in tropical forests are mediated by logging intensity.

Science.gov (United States)

Roopsind, Anand; Caughlin, T Trevor; van der Hout, Peter; Arets, Eric; Putz, Francis E

2018-03-30

Forest degradation accounts for ~ 70% of total carbon losses from tropical forests. Substantial emissions are from selective logging, a land-use activity that decreases forest carbon density. To maintain carbon values in selectively logged forests, climate change mitigation policies and government agencies promote the adoption of reduced-impact logging (RIL) practices. However, whether RIL will maintain both carbon and timber values in managed tropical forests over time remains uncertain. In this study, we quantify the recovery of timber stocks and aboveground carbon at an experimental site where forests were subjected to different intensities of RIL (4 trees ha -1 , 8 trees ha -1 , and 16 trees ha -1 ). Our census data spans 20 years post-logging and 17 years after the liberation of future crop trees from competition in a tropical forest on the Guiana Shield, a globally important forest carbon reservoir. We model recovery of timber and carbon with a breakpoint regression that allowed us to capture elevated tree mortality immediately after logging. Recovery rates of timber and carbon were governed by the presence of residual trees (i.e., trees that persisted through the first harvest). The liberation treatment stimulated faster recovery of timber albeit at a carbon cost. Model results suggest a threshold logging intensity beyond which forests managed for timber and carbon derive few benefits from RIL, with recruitment and residual growth not sufficient to offset losses. Inclusion of the breakpoint at which carbon and timber gains outpaced post-logging mortality led to high predictive accuracy, including out-of-sample R 2 values >90%, and enabled inference on demographic changes post-logging. Our modeling framework is broadly applicable to studies that aim to quantify impacts of logging on forest recovery. Overall, we demonstrate that initial mortality drives variation in recovery rates, that the second harvest depends on old growth wood, and that timber

36 CFR 223.7 - Permission for free use of timber outside free-use areas.

Science.gov (United States)

2010-07-01

..., DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER General Provisions § 223.7 Permission for free use of timber outside free-use areas. Similar material may be cut outside of a free-use area without permit in cases of emergency, but the person taking such material shall promptly notify...

Projecting Timber Inventory at the Product Level

Science.gov (United States)

Lawrence Teeter; Xiaoping Zhou

1999-01-01

Current timber inventory projections generally lack information on inventory by product classes. Most models available for inventory projection and linked to supply analyses are limited to projecting aggregate softwood and hardwood. The research presented describes a methodology for distributing the volume on each FIA (USDA Forest Service Forest Inventory and Analysis...

31 CFR 593.510 - Transactions related to the importation of any round log or timber product originating in Liberia...

Science.gov (United States)

2010-07-01

... importation of any round log or timber product originating in Liberia authorized. 593.510 Section 593.510... importation of any round log or timber product originating in Liberia authorized. Except as otherwise... into the United States of any round log or timber product originating in Liberia are authorized. ...

2005 wood harvests in France - a definite recovery for timber and dendro-energy

International Nuclear Information System (INIS)

Cinotti, B.

2007-01-01

After dropping to 32.8 million m 3 in 2003, sales of wood harvests continue the recovery that began in 2004 and have reached 37.2 million m 3 (+ 5%) i.e., slightly more than the level reached prior to the 1999 storms (36.9 million m 3 ). Workable timber sales have increased by 5.9% up to 22.1 million m 3 but are nonetheless 4.5% below their 1999 level (23.2 million m 3 ). Industrial round-wood harvests have remained stable at 12.2 million m 3 (of which 11.8 are pulpwood). Sales of firewood have increased 23% (2.9 million m 3 ). Pre-tax roadside value of the entire wood harvest is estimated to be 1.64 billion Euro. French production of sawing timber is 9.7 million cubic metres with sawn softwood timber stagnating (+ 0.5%) and a drop in sawn hardwood timber (- 4.6%). The effects of the storms at the end of 1999 on the business cycle are no longer perceptible. Their consequences on the structure of harvests and of businesses are beginning to be understood. Average wood prices increased considerably in 2005 and 2006. These rosier market conditions for unprocessed timber could be an opportunity to continue with restructuring of the sector, in particular so as to further streamline harvests and narrow the wide gap between loggable and actually logged volumes, as well as to review the distribution of added value between the various players in the forest-based industries. (authors)

Fire resistance in American heavy timber construction history and preservation

CERN Document Server

Heitz, Jesse

2016-01-01

This volume presents a history of heavy timber construction (HTC) in the United States, chronicling nearly two centuries of building history, from inception to a detailed evaluation of one of the best surviving examples of the type, with an emphasis on fire resistance. The book does not limit itself in scope to serving only as a common history. Rather, it provides critical analysis of HTC in terms of construction methods, design, technical specifications, and historical performance under fire conditions. As such, this book provides readers with a truly comprehensive understanding and exploration of heavy timber construction in the United States and its performance under fire conditions.

Timber joints under long-term loading

DEFF Research Database (Denmark)

Feldborg, T.; Johansen, M.

This report describes tests and results from stiffness and strength testing of splice joints under long-term loading. During two years of loading the spicimens were exposed to cyclically changing relative humidity. After the loading period the specimens were short-term tested. The connectors were...... integral nail-plates and nailed steel and plywood gussets. The report is intended for designers and researchers in timber engineering....

Grading timber and glued structural members

Science.gov (United States)

David E. Kretschmann; Roland Hernandez

2006-01-01

Because of its biological nature, which is influenced by many factors as discussed in Chapter 6, the quality of timber is enormously variable. Therefore, some sort of arrangement or classification must be undertaken prior to its use, in order to get the most out of this valuable resource. It is obvious that not all lumber can be used for the same purposes because not...

Residual load carrying capacity of timber joints

NARCIS (Netherlands)

Kuilen, J.W.G. van de

1999-01-01

Timber joints that have been preloaded for 2 to 8 years have been short term tested in accordance with EN 26891. The applied load levels varied between 30% and 50% of the average short term strength. The study comprised nailed, toothed-plate and split-ring joints. All joints were made of spruce and

Forests, timber and rural livelihoods

DEFF Research Database (Denmark)

Hansen, Christian Pilegaard; Pouliot, Mariève; Marfo, Emmanuel

2015-01-01

Based on detailed income data of 478 rural households, the nexus between forest, trees and rural livelihoods in Ghana is investigated and applied to assess implications of the Voluntary Partnership Agreement (VPA) between the EU and Ghana on illegal logging. It is found that, after crops...... and benefits to trees on farm and fallow land to those occupying and cultivating the land. Such efforts would provide incentive for timber production and thus enhance rural livelihoods, while combatting illegal logging, deforestation and forest degradation....

Socio-economic factors influencing marketing of non-timber forest ...

African Journals Online (AJOL)

Socio-economic factors influencing marketing of non-timber forest products in ... enhance skills for product transformation, build innovative storage facilities, and ... the process of domestication and integration in traditional land-use systems.

NDE investigation of the timber foundation in the historic Kennecott Mine Concentration Mill Building

Science.gov (United States)

James P. Wacker; Xiping Wang; Douglas R. Rammer; Bessie M. Woodward

2011-01-01

The U.S. National Park Service acquired the National Historic Copper Mine at Kennecott, Alaska, in 1998. There was uncertainty about the condition of the timber-cribbing foundation supporting the concentration mill, the largest building in the mine complex. A comprehensive on-site evaluation of the timber cribbing foundation was performed in summer 2009. The inspection...

36 CFR 223.85 - Noncompetitive sale of timber.

Science.gov (United States)

2010-07-01

... further advertisement, at not less than appraised value, any timber previously advertised for competitive... degradation or resource damage, or as the result of administrative appeals, litigation, or court orders... any applicable appeals or objection process has been completed may be considered for replacement...

CONTRIBUTION TO THE POTENTIAL OF USING FRP MATERIALS IN THE REHABILITATION AND STABILIZATION OF TIMBERED BUILDINGS

Directory of Open Access Journals (Sweden)

Tomáš Čejka

2015-12-01

Full Text Available Wooden log, timbered perimeter and interior walls ranked among the most common building constructions used from the Early Middle Ages. In most cases, the local natural resources, i.e. wood, clay, straw and stone, were used for building houses with wooden framing. This article outlines typical defects and failures of timbered houses, “classic” techniques for the rehabilitation of these defects and failures indicating the potential of using composite materials based on high- strength fibres and epoxy resin in the rehabilitation and strengthening of timbered buildings.

Roof timber for fortifying mining works

Energy Technology Data Exchange (ETDEWEB)

Shirokov, A P; Kuntsevich, V IK; Pishchulin, V V; Seryi, A M; Volkov, P A

1981-05-15

The roof timber for fortifying mining works includes spring-mounted hinged elements made from a special rolled metal. In order to increase the carrying capacity of the support by increasing the deformation threshold, the springs are mounted by their expanded section to the lower side of the hinge; their ends are connected in turn to the elements made from the special rolled metal on both sides of the hinge.

ECOLOGICAL EFFECT OF TIMBER EXPRACTION IN OHIMINI LGA ...

African Journals Online (AJOL)

Shima

as Indonesia, Thailand, Malaysia, ... reduced biodiversity (Wikipedia, 2007). In many countries massive timber extraction is ongoing and is shaping climate and geography. logging affects the amount of water in the soil and groundwater and the moisture in the atmosphere. Forests support considerable biodiversity, providing.

Simulation-Based Multiobjective Optimization of Timber-Glass Residential Buildings in Severe Cold Regions

Directory of Open Access Journals (Sweden)

Yunsong Han

2017-12-01

Full Text Available In the current context of increasing energy demand, timber-glass buildings will become a necessary trend in sustainable architecture in the future. Especially in severe cold zones of China, energy consumption and the visual comfort of residential buildings have attracted wide attention, and there are always trade-offs between multiple objectives. This paper aims to propose a simulation-based multiobjective optimization method to improve the daylighting, energy efficiency, and economic performance of timber-glass buildings in severe cold regions. Timber-glass building form variables have been selected as the decision variables, including building width, roof height, south and north window-to-wall ratio (WWR, window height, and orientation. A simulation-based multiobjective optimization model has been developed to optimize these performance objectives simultaneously. The results show that Daylighting Autonomy (DA presents negative correlations with Energy Use Intensity (EUI and total cost. Additionally, with an increase in DA, Useful Daylighting Illuminance (UDI demonstrates a tendency of primary increase and then decrease. Using this optimization model, four building performances have been improved from the initial generation to the final generation, which proves that simulation-based multiobjective optimization is a promising approach to improve the daylighting, energy efficiency, and economic performances of timber-glass buildings in severe cold regions.

XAS studies of the effectiveness of iron chelating treatments of Mary Rose timbers

International Nuclear Information System (INIS)

Berko, A; Schofield, E J; Chadwick, A V; Smith, A D; Jones, A M; Mosselmans, J F W

2009-01-01

The oxidation of sulfur in marine archaeological timbers under museum storage conditions is a recently identified problem, particularly for major artefacts such as historic ships excavated from the seabed. Recent work on the Vasa has stressed the role of iron in catalysing the oxidative degradation of the wood cellulose and the polyethylene glycols used to restore mechanical integrity to the timbers. In developing new treatment protocols for the long term preservation of Henry VIII of England's flagship, the Mary Rose, we are investigating the potential of chelating agents to neutralise and remove the iron products from the ships timbers. We have explored the use of aqueous solutions of chelating agents of calcium phytate, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) and ammonium citrate to extract the iron compounds. All of these solutions exhibit some level of iron removal; however the key is to find the most effective concentration at pH of around 7 of the reagent solution, to minimise the treatment time and find the most cost-effective treatment for the whole of the Mary Rose hull. Fe K-edge XAFS data from samples of Mary Rose timbers, before and after treatment by the chelating agents mentioned has been collected. The data collected provide valuable insights into the effectiveness of the treatment solutions.

Effects of Inhalation of Emissions from Cedar Timber on Psychological and Physiological Factors in an Indoor Environment

Directory of Open Access Journals (Sweden)

Kenichi Azuma

2016-12-01

Full Text Available Components extracted from cedar timber have been reported to have stress-reducing effects in humans. If the positive effects of cedar timber in indoor environments are scientifically proven, an indoor environment that utilizes cedar timber may contribute to the improvement or promotion of well-being in humans. In this study, we evaluated the effects of inhaling emissions of volatile constituents from cedar timber (Cryptomeria japonica on the psychological and physiological factors in indoor environments. A case-control study with a crossover design was conducted with 10 subjects occupying two rooms that were controlled for interior materials, indoor climate, and room size. Cedrol and β-eudesmol were specifically detected in the case room. However, no significant differences were observed in psychological and physiological factors. There was a significant loss in vigor in the control group from the time before entering the room to the time after leaving the room; however, this loss in vigor was not seen in the case group. Temperature conditions were higher than the indoor environmental standard in Japan but similar in the two groups. Our results showed a minor positive change in vigor among participants exposed to cedar timber for a short term. Inhalation of emissions of volatile constituents from cedar timber may have positive effects in humans; however, further research on their efficacy is needed.

Experimental verification of a weak zone model for timber in bending

DEFF Research Database (Denmark)

Källsner, B.; Ditlevsen, Ove Dalager; Salmela, K.

1997-01-01

In order to verify a stochastic model for the variation of bending strength within and between structural timber members, tests with long members subjected to constant bending moment have been performed. The span with constant moment contained between five and nine weak zones, i.e. zones...... with a cluster of knots. In a previous investigation test specimens, each containing one weak zone, have been tested in bending separately. Based on these tests a hierarchical model with two levels was formulated. The test results show that the bending strength of the long timber members on the average is 5...

Sustainable forest management of tropical forests can reduce carbon emissions and stabilize timber production

Science.gov (United States)

N. Sasaki; G.P. Asner; Yude Pan; W. Knorr; P.B. Durst; H.O. Ma; I. Abe; A.J. Lowe; L.P. Koh

2016-01-01

The REDD+ scheme of the United Nations Framework Conventionon Climate Change has provided opportunities to manage tropical forests for timber production and carbon emission reductions. To determine the appropriate loggingtechniques, we analyzed potential timber production and carbon emission reductions under two logging techniques over a 40-year period of selective...

Timber harvesting patterns for major states in the central, northern, and mid-Atlantic hardwood regions

Science.gov (United States)

William G. Luppold; Matthew S. Bumgardner

2018-01-01

Timber harvesting is a major disturbance agent influencing the composition and structure of eastern hardwood forests. To better understand timber harvesting practices, we examined roundwood harvesting patterns in 13 eastern states in the Central, Mid-Atlantic, and Northern regions that contained high proportional volumes of hardwood in their forest inventories. Nearly...

The Load-Bearing Capacity of Timber-Glass Composite I-Beams Made with Polyurethane Adhesives

Science.gov (United States)

Rodacki, Konrad

2017-12-01

This article discusses the issue of composite timber-glass I-beams, which are an interesting alternative for load-bearing beams of ceilings and roofs. The reasoning behind the use of timber-glass I-beams is the combination of the best features of both materials - this enables the creation of particularly safe beams with regard to structural stability and post-breakage load capacity. Due to the significant differences between the bonding surfaces of timber and glass, a study on the adhesion of various adhesives to both surfaces is presented at the beginning of the paper. After examination, two adhesives were selected for offering the best performance when used with composite beams. The beams were investigated using a four-point bending test under quasi-static loading.

Analysis and modelling composite timber-concrete systems: Design of bridge structure according to EN

Directory of Open Access Journals (Sweden)

Manojlović Dragan

2016-01-01

Full Text Available Timber-concrete composite structures are already applied more than 80 years in engineering practice, went trought the intuitive problem solution to the fully prefabricated hybride assemblies for dry building. The development path of timber-concrete composites was always followed by extensive theoretical and experimental research, whose results were successfully implemented in practice, i.e. on the market, but till presence didn't result in modern designer's code. In expectation of new European codes for timber-concrete composites, the objective of the paper is to provide a comprehensive review of available standards provisions and recent conclusions from literature. The key issues for practical design are highlighted and ilustrated on the example of glulam composite arch bridge structure with concrete deck, according the Eurocodes.

epidemiology of eye diseases among timber workers in owerri

African Journals Online (AJOL)

LIVINGSTON

pinguecula and uveitis, each, accounting for 39.52%, 31.10%, 12.53%, 7.34% and 2.16% respectively ... Timber workers, eye diseases, work environment, prevalence, environmental pollutants. ... there was no interested family member to take.

Stiffness analysis of glued connection of the timber-concrete structure

Science.gov (United States)

Daňková, Jana; Mec, Pavel; Majstríková, Tereza

2016-01-01

This paper presents results of experimental and mathematical analysis of stiffness characteristics of a composite timber-concrete structure. The composite timberconcrete structure presented herein is non-typical compared to similar types of building structures. The interaction between the timber and concrete part of the composite cross-section is not based on metal connecting elements, but it is ensured by a glued-in perforated mesh made of plywood. The paper presents results of experimental and mathematical analysis for material alternatives of the solution of the glued joint. The slip modulus values were determined experimentally. Data obtained from the experiment evaluated by means of regression analysis. Test results were also used as input data for the compilation of a 3D model of a composite structure by means of the 3D finite element model. On the basis of result evaluation, it can be stated that the stress-deformation behaviour at shear loading of this specific timber-concrete composite structure can be affected by the type of glue used. Parameters of the 3D model of both alternative of the structure represent well the behaviour of the composite structure and the model can be used for predicting design parameters of a building structure.

Study on the changes of properties of Myanma lesser-used timber species following gamma-irradiation

International Nuclear Information System (INIS)

Kaye Thwe Kywe Aye; Win Kyi; Tin Hlaing

2001-01-01

The proper changes of some physical properties and mechanical properties of Leza [Laderstroemra tomentofa (PREFL.)] one of Myanmar lesser-used timber species, following radiation processing with 1 Mrad gamma-radiation has been studied. It is found that some properties of Leza-timber species are significantly changed at 95 percent confidence level. (author)

Melatonin-induced CBF/DREB1s are essential for diurnal change of disease resistance and CCA1 expression in Arabidopsis.

Science.gov (United States)

Shi, Haitao; Wei, Yunxie; He, Chaozu

2016-03-01

Melatonin (N-acetyl-5-methoxytryptamine) is an important regulator of circadian rhythms and immunity in animals. However, the diurnal changes of endogenous melatonin and melatonin-mediated diurnal change of downstream responses remain unclear in Arabidopsis. Using the publicly available microarray data, we found that the transcript levels of two melatonin synthesis genes (serotonin N-acetyltransferase (SNAT) and caffeate O-methyltransferase (COMT)) and endogenous melatonin level were regulated by diurnal cycles, with different magnitudes of change. Moreover, the transcripts of C-repeat-binding factors (CBFs)/Drought response element Binding 1 factors (DREB1s) were co-regulated by exogenous melatonin and diurnal changes, indicating the possible correlation among clock, endogenous melatonin level and AtCBFs expressions. Interestingly, diurnal change of plant immunity against Pst DC3000 and CIRCADIANCLOCK ASSOCIATED 1 (CCA1) expression were largely lost in AtCBFs knockdown line-amiR-1. Taken together, this study identifies the molecular pathway underlying the diurnal changes of immunity in Arabidopsis. Notably, the diurnal changes of endogenous melatonin may regulate corresponding changes of AtCBF/DREB1s expression and their underlying diurnal cycle of plant immunity and AtCCA1. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

36 CFR 223.187 - Determinations of unprocessed timber.

Science.gov (United States)

2010-07-01

... generally recognized by the industry as setting a selling standard; and, (ii) A statement by the... setting a selling standard. (3) Lumber, construction timbers, or cants for remanufacture, except western... or better, with a maximum cross section of 2,000 square centimeters (310 square inches) for any...

Advantages of DVW reinforced moment transmitting timber joints with steel flitch plates for colum-beam application

NARCIS (Netherlands)

Leijten, A.J.M.; Brandon, D.; Haddad, Y.M.

2013-01-01

This paper presents a study into the moment-rotation aspects of dvw (densified veneer wood) reinforced timber connections with an inter-connecting flitch plate used as middle member. Previous studies showed that reinforcing dowel-type timber connections with dvw and using expanded tube fasteners

Long-term monitoring and field testing of an innovative multistory timber building

Science.gov (United States)

Omenzetter, Piotr; Morris, Hugh; Worth, Margaret; Kohli, Varun; Uma, S. R.

2011-04-01

An innovative three-story timber building, using self-centering, post-tensioned timber shear walls as the main horizontal load resisting system and lightweight composite timber-concrete floors, has recently been completed in Nelson, New Zealand. It is expected to be the trailblazer for similar but taller structures to be more widely adopted. Performance based standards require an advanced understanding of building responses and in order to meet the need for in-situ performance data the building has been subjected to forced vibration testing and instrumented for continuous monitoring using a total of about 90 data channels to capture its dynamic and long-term responses. The first part of the paper presents a brief discussion of the existing research on the seismic performance of timber frame buildings and footfall induced floor vibrations. An outline of the building structural system, focusing on the novel design solutions, is then discussed. This is followed by the description of the monitoring system. The paper emphasizes the need for optimal placement of a limited number of sensors and demonstrates how this was achieved for monitoring floor vibrations with the help of the effective independence-driving point residue (EfI-DPR) technique. A novel approach to the EfI-DPR method proposed here uses a combinatorial search algorithm that increases the chances of obtaining the globally optimal solution. Finally, the results from the forced vibration tests conducted on the whole building at different construction stages are reviewed.

Implementation of fully coupled heat and mass transport model to determine the behaviour of timber elements in fire

DEFF Research Database (Denmark)

Pečenko, Robert; Huč, Sabina; Turk, Goran

2014-01-01

In this paper we present results of numerical analysis of timber beam exposed to fire. The numerical procedure is divided into two physically separated but closely related phases. In the first phase coupled problem of moisture and heat transfer over the timber beam is numerically solved using...... the enhanced finite element method. The results of the first computational stage were used as the input data for the numerical analysis of mechanical response of timber element....

Profitability of Clerodendrum volubile (eweta) , a non-timber forest ...

African Journals Online (AJOL)

Timber Forest product, in Okitipupa, Ondo State Nigeria. Purposive and simple random sampling techniques were used in the selection of markets and respondents. The sample size was 60 and instrument of data collection was structured and ...

Forest biomass flow for fuel wood, fodder and timber security among tribal communities of Jharkhand.

Science.gov (United States)

Islam, M A; Quli, S M S; Rai, R; Ali, Angrej; Gangoo, S A

2015-01-01

The study investigated extraction and consumption pattern of fuel wood, fodder and timber and forest biomass flow for fuel wood, fodder and timber security among tribal communities in Bundu block of Ranchi district in Jharkhand (India). The study is based on personal interviews of the selected respondents through structured interview schedule, personal observations and participatory rural appraisal tools i.e. key informant interviews and focus group discussions carried out in the sample villages, using multi-stage random sampling technique. The study revealed that the total extraction of fuel wood from different sources in villages was 2978.40 tons annum(-1), at the rate of 0.68 tons per capita annum(-1), which was mostly consumed in cooking followed by cottage industries, heating, community functions and others. The average fodder requirement per household was around 47.77 kg day(-1) with a total requirement of 14227.34 tons annum(-1). The average timber requirement per household was computed to be 0.346 m3 annum(-1) accounting for a total timber demand of 282.49 m3 annum(-1), which is mostly utilized in housing, followed by agricultural implements, rural furniture, carts and carriages, fencing, cattle shed/ store house and others. Forest biomass is the major source of fuel wood, fodder and timber for the primitive societies of the area contributing 1533.28 tons annum(-1) (51.48%) of the total fuel wood requirement, 6971.55 tons annum(-1) (49.00%) of the total fodder requirement and 136.36 m3 annum(-1) (48.27%) of the total timber requirement. The forest biomass is exposed to enormous pressure for securing the needs by the aboriginal people, posing great threat to biodiversity and environment of the region. Therefore, forest biomass conservation through intervention of alternative avenues is imperative to keep pace with the current development and future challenges in the area.

Effects of timber harvest on aquatic vertebrates and habitat in the North Fork Caspar Creek

Science.gov (United States)

Rodney J. Nakamoto

1998-01-01

I examined the relationships between timber harvest, creek habitat, and vertebrate populations in the North and South forks of Caspar Creek. Habitat inventories suggested pool availability increased after the onset of timber harvest activities. Increased large woody debris in the channel was associated with an increase in the frequency of blowdown in the riparian...

The Integration of Timber Enterprises of the Khanty-Mansiysk Autonomous Okrug — Yugra

Directory of Open Access Journals (Sweden)

Irina Anatolyevna Kislukhina

2018-03-01

Full Text Available The article investigates the timber enterprises’ integration in Khanty-Mansiysk Autonomous Okrug — Yugra as a way to improve the efficiency of the timber industry. Currently, in the region, only 10 of 130 timber enterprises are large and mediumsized enterprises. The other companies are small and chronically underfunded. These small enterprises use outdated equipment and production technology, are unable to organize wood processing and reforestation; to develop forest infrastructure. However, the integration of timber industry enterprises can become the way to address this situation. The article discusses various types of possible enterprises’ integration, such as vertical and horizontal integrations, the combined and unrelated diversification (financial integration. The combined diversification is a mixed type of the integration of enterprises from related and unrelated industries. This type of integration is most in keeping with the characteristics of the development of timber industry of Khanty- Mansiysk Autonomous Okrug — Yugra. The combined diversification will maximize the effect from the association of enterprises. The author has justified the rationale for establishing six integrated industrial and financial associations (IIFA according to improved forest and economical zoning of Okrug area. I defined the profile of each IIFA taking into account of special aspects of forest resources as well as social and economical development characteristics of the area and demand for the products. In Khanty-Mansiysk Autonomous Okrug — Yugra, the integrated industrial and financial associations will address four critical challenges of the socio-economic development of the region. Firstly, these associations will contribute to the diversification of the economy. Secondly, they will enable the production of new types of forest products. Thirdly, the creation of the integrated industrial and financial associations will increase the efficiency in

Timber resource of Wisconsin's Northwest Survey Unit, 1983.

Science.gov (United States)

W. Brad Smith

1984-01-01

The fourth inventory of the timber resource of the Northwest Wisconsin Survey Unit shows a 1.8% decline in commercial forest area and a 36% gain in growing-stock volume between 1968 and 1983. Presented are highlights and statistics on area, volume, growth, mortality, removals, utilization, and biomass.

Removal of muscle artifact from EEG data: comparison between stochastic (ICA and CCA) and deterministic (EMD and wavelet-based) approaches

Science.gov (United States)

Safieddine, Doha; Kachenoura, Amar; Albera, Laurent; Birot, Gwénaël; Karfoul, Ahmad; Pasnicu, Anca; Biraben, Arnaud; Wendling, Fabrice; Senhadji, Lotfi; Merlet, Isabelle

2012-12-01

Electroencephalographic (EEG) recordings are often contaminated with muscle artifacts. This disturbing myogenic activity not only strongly affects the visual analysis of EEG, but also most surely impairs the results of EEG signal processing tools such as source localization. This article focuses on the particular context of the contamination epileptic signals (interictal spikes) by muscle artifact, as EEG is a key diagnosis tool for this pathology. In this context, our aim was to compare the ability of two stochastic approaches of blind source separation, namely independent component analysis (ICA) and canonical correlation analysis (CCA), and of two deterministic approaches namely empirical mode decomposition (EMD) and wavelet transform (WT) to remove muscle artifacts from EEG signals. To quantitatively compare the performance of these four algorithms, epileptic spike-like EEG signals were simulated from two different source configurations and artificially contaminated with different levels of real EEG-recorded myogenic activity. The efficiency of CCA, ICA, EMD, and WT to correct the muscular artifact was evaluated both by calculating the normalized mean-squared error between denoised and original signals and by comparing the results of source localization obtained from artifact-free as well as noisy signals, before and after artifact correction. Tests on real data recorded in an epileptic patient are also presented. The results obtained in the context of simulations and real data show that EMD outperformed the three other algorithms for the denoising of data highly contaminated by muscular activity. For less noisy data, and when spikes arose from a single cortical source, the myogenic artifact was best corrected with CCA and ICA. Otherwise when spikes originated from two distinct sources, either EMD or ICA offered the most reliable denoising result for highly noisy data, while WT offered the better denoising result for less noisy data. These results suggest that

Modeling the complex impacts of timber harvests to find optimal management regimes for Amazon tidal floodplain forests

Science.gov (United States)

Fortini, Lucas B.; Cropper, Wendell P.; Zarin, Daniel J.

2015-01-01

At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine

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...

Local timber firm looking forward to develop on medium term

Directory of Open Access Journals (Sweden)

BUCS Lorant

2017-01-01

Full Text Available This article intends to outline the challenges faced by a local timber company in struggle to resist on medium-term on the market. There will be revealed the challenges the company is facing, and also the ways to adapt to the changing world of timber industry. There will be presented a short history of the founding and the evolution of the company on the local and international market, pointing out the relevant events which have marked the life of the company during the years. There will also be presented a short review of the competition on the market and the marketing strategy and policies which the company is using to be able to face the new challenges.

3 CFR - Establishment of the Interagency Committee on Trade in Timber Products from Peru and Assignment...

Science.gov (United States)

2010-01-01

... in Timber Products from Peru and Assignment of Function under Section 501 of the United States-Peru... Memorandum of May 1, 2009 Establishment of the Interagency Committee on Trade in Timber Products from Peru and Assignment of Function under Section 501 of the United States-Peru Trade Promotion Agreement...

32 CFR 644.551 - Equal opportunity-sales of timber, embedded sand, gravel, stone, and surplus structures.

Science.gov (United States)

2010-07-01

... § 644.551 Equal opportunity—sales of timber, embedded sand, gravel, stone, and surplus structures... 32 National Defense 4 2010-07-01 2010-07-01 true Equal opportunity-sales of timber, embedded sand, gravel, stone, and surplus structures. 644.551 Section 644.551 National Defense Department of Defense...

Engineering evaluation of 55-year-old timber columns recycled from an industrial military building

Science.gov (United States)

Robert H. Falk; David Green; Douglas Rammer; Scott F. Lantz

2000-01-01

A large sample of timber was collected from a 548,000-ft.2 (50,900-m2) World War II era industrial military building containing approximately 1, 875,000 board feet (4,400 m3) of lumber and timber. Sixty 12-foot- (3.6-m-) long, nominal 8- by 8-inches (190-by 190-mm) Douglas-fir columns were tested at the USDA Forest Service, Forest Products Laboratory, and the results...

The privately owned timber resources of western Oregon.

Science.gov (United States)

Donald R. Gedney

1983-01-01

Timber resource statistics from a 1973-76 inventory are presented for private timberland in western Oregon. Inventories usually classify private owners as either forest industry or nonindustrial private. For this report, however, the nonindustrial private classification has been further disaggregated into farmer, individual, and corporate owners. For all private owner...

Determining modulus of elasticity of ancient structural timber

Science.gov (United States)

Houjiang Zhang; Lei Zhu; Yanliang Sun; Xiping Wang; Haicheng Yan

2011-01-01

During maintenance of ancient timber architectures, it is important to determine mechanical properties of the wood component materials non-destructively and effectively, so that degraded members may be replaced or repaired to avoid structural failure. Experimental materials are four larch (Larix principis-rupprechtii Mayr.) components, which were taken down from the...

The Effect of Urban Sprawls on Timber Harvesting

Science.gov (United States)

Stephen A. Barlow; Ian A Munn; David A. Cleaves; David L. Evans

1998-01-01

In Mississippi and Alabama, urban population growth is pushing development into rural areas. To study the impact of urbanization on timber harvesting, census and forest inventory data were combined in a geographic information system, and a logistic regression model was used to estimate the relationship between several variables and harvest probabilities....

FIELD-SCALE LEACHING OF ARSENIC, CHROMIUM AND COPPER FROM WEATHERED TREATED WOOD

Science.gov (United States)

Hasan, A. Rasem; Hu, Ligang; Solo-Gabriele, Helena M.; Fieber, Lynne; Cai, Yong; Townsend, Timothy G.

2010-01-01

Earlier studies documented the loss of wood preservatives from new wood. The objective of this study was to evaluate losses from weathered treated wood under field conditions by collecting rainfall leachate from 5 different wood types, all with a surface area of 0.21 m2. Wood samples included weathered chromate copper arsenate (CCA) treated wood at low (2.7 kg/m3), medium (4.8 kg/m3) and high (35.4 kg/m3) retention levels, new alkaline copper quat (ACQ) treated wood (1.1 kg/m3 as CuO) and new untreated wood. Arsenic was found to leach at a higher rate (100 mg in 1 year for low retention) than chromium and copper (leached at the highest rate from the ACQ sample (670 mg). Overall results suggest that metals’ leaching is a continuous process driven by rainfall, and that the mechanism of release from the wood matrix changes as wood weathers. PMID:20053493

Amount of leachant and water absorption levels of wood treated with borates and water repellents.

Science.gov (United States)

Baysal, Ergun; Sonmez, Abdullah; Colak, Mehmet; Toker, Hilmi

2006-12-01

Wood protection efficacy of borates against biological agents, flame retardancy, and suitability to the environment is well known. Since borates can be applied to timber as water based solutions, they are preferred economically as well. Even though they are highly mobile in wood, boron compounds are widely used in timber preservation. Borates migrate in liquid and increase the hygroscopicity of wood in damp conditions. This study deals with the physical restriction of water access in wood by impregnating water repellent agents into wood to limit amount of leachant and water absorption levels of wood after boron treatment. Borates were incorporated with polyethylene glycol-400 (PEG-400) their bulking effect in wood was considered. Results indicated that the amount of leachates from wood treated with borates in PEG-400 was remarkably higher compared to those of wood treated with the aqueous solutions of borates. Water absorption (WA) levels of wood treated with aqueous solutions of borates were higher than those of their treated samples with the solutions in PEG-400. Secondary treatments of wood with the water repellent (WR) chemicals following borate impregnation reduced the leaching of chemicals from wood in water and also WA of the specimens were less than those of the wood treated with only borates from aqueous and PEG solutions. Styrene (St) was the most effective monomer among the other agents used in terms of immobility effect on borates and WA.

Impact of timber production and transport costs on stand management

Science.gov (United States)

Chris B. LeDoux; Chris B. LeDoux

1988-01-01

Evaluates the impact of cable logging technology, transportation network standards, and transport vehicles on stand management. Managers can use results to understand the impact of timber production costs on eastern hardwood management.

Montana's forest products industry and timber harvest, 2004

Science.gov (United States)

Timothy P. Spoelma; Todd A. Morgan; Thale Dillon; Alfred L. Chase; Charles E. Keegan; Larry T. DeBlander

2008-01-01

This report traces the flow of Montana's 2004 timber harvest through the primary wood-using industries; provides a description of the structure, capacity, and condition of Montana's primary forest products industry; and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as changes in harvest, production...

Timber resource statistics for Washington, January 1, 1973.

Science.gov (United States)

Patricia M. Bassett; Grover A. Choate

1974-01-01

Timber resource statistics to January 1, 1973, for the State of Washington show total land area, commercial timberland area, and growing stock and sawtimber inventory volumes by county and owner group. Growth and removals are shown by Forest Survey inventory unit for 1972. Each National Forest is updated to January 1, 1973.

Disruption of endocytic trafficking protein Rab7 impairs invasiveness of cholangiocarcinoma cells.

Science.gov (United States)

Suwandittakul, Nantana; Reamtong, Onrapak; Molee, Pattamaporn; Maneewatchararangsri, Santi; Sutherat, Maleerat; Chaisri, Urai; Wongkham, Sopit; Adisakwattana, Poom

2017-09-07

Alterations and mutations of endo-lysosomal trafficking proteins have been associated with cancer progression. Identification and characterization of endo-lysosomal trafficking proteins in invasive cholangiocarcinoma (CCA) cells may benefit prognosis and drug design for CCA. To identify and characterize endo-lysosomal trafficking proteins in invasive CCA. A lysosomal-enriched fraction was isolated from a TNF-α induced invasive CCA cell line (KKU-100) and uninduced control cells and protein identification was performed with nano-LC MS/MS. Novel lysosomal proteins that were upregulated in invasive CCA cells were validated by real-time RT-PCR. We selected Rab7 for further studies of protein level using western blotting and subcellular localization using immunofluorescence. The role of Rab7 in CCA invasion was determined by siRNA gene knockdown and matrigel transwell assay. Rab7 mRNA and protein were upregulated in invasive CCA cells compared with non-treated controls. Immunofluorescence studies demonstrated that Rab7 was expressed predominantly in invasive CCA cells and was localized in the cytoplasm and lysosomes. Suppression of Rab7 translation significantly inhibited TNF-α-induced cell invasion compared to non-treated control (p= 0.044). Overexpression of Rab7 in CCA cells was associated with cell invasion, supporting Rab7 as a novel candidate for the development of diagnostic and therapeutic strategies for CCA.

An improved method for calculating force distributions in moment-stiff timber connections

DEFF Research Database (Denmark)

Ormarsson, Sigurdur; Blond, Mette

2012-01-01

An improved method for calculating force distributions in moment-stiff metal dowel-type timber connections is presented, a method based on use of three-dimensional finite element simulations of timber connections subjected to moment action. The study that was carried out aimed at determining how...... the slip modulus varies with the angle between the direction of the dowel forces and the fibres in question, as well as how the orthotropic stiffness behaviour of the wood material affects the direction and the size of the forces. It was assumed that the force distribution generated by the moment action...

Using experimental modal analysis to assess the behaviour of timber elements

Science.gov (United States)

Kouroussis, Georges; Fekih, Lassaad Ben; Descamps, Thierry

2018-03-01

Timber frameworks are one of the most important and widespread types of structures. Their configurations and joints are usually complex and require a high level of craftsmanship to assemble. In the field of restoration, a good understanding of the structural behaviour is necessary and is often based on assessment techniques dedicated to wood characterisation. This paper presents the use of experimental modal analysis for finite element updating. To do this, several timber beams in a free supported condition were analysed in order to extract their bending natural characteristics (frequency, damping and mode shapes). Corresponding ABAQUS finite element models were derived which included the effects of local defects (holes, cracks and wood nodes), moisture and structural decay. To achieve the modal updating, additional simulations were performed in order to study the sensitivity of the mechanical parameters. With the intent to estimate their mechanical properties, a procedure of modal updating was carried out in MatLab with a Python script. This was created to extract the modal information from the ABAQUS modal analysis results to be compared with the experimental results. The updating was based on a minimum of unconstrained multivariable function using a derivative-free method. The objective function was selected from the conventional comparison tools (absolute or relative frequency difference, and/or modal assurance criterion). This testing technique was used to determine the dynamic mechanical properties of timber beams, such as the anisotropic Young's Moduli and damping ratio. To verify the modulus, a series of static 4-point bending tests and STS04 classifications were conducted. The results also revealed that local defects have a negligible influence on natural frequencies. The results demonstrate that this assessment tool offers an effective method to obtain the mechanical properties of timber elements, especially when on-site and non-destructive techniques are

MODAL ANALYSIS OF REAL TIMBER FRAME HOUSES WITH DIFFERENT INSULATION MATERIALS

Directory of Open Access Journals (Sweden)

Marcin Szczepański

2016-09-01

Full Text Available The aim of this article is to present the results of a numerical modal analysis of two actual structures of timber frame buildings and the different behaviour due to the used insulation material. One model of the timber structure was filled with mineral wool, while the other with polyurethane foam. During the modal analysis, eigenvalues for both models have been determined. The results of the analysis clearly show the increase of stiffness and damping properties of skeletal constructions achieved by the use of polyurethane foam as the skeleton filling. The numerical model was based on prior experimental test on real scale single frame elements, therefore the result can be assumed to be adequate.

Chapter 1: CLT Introduction to cross-laminated timber

Science.gov (United States)

Sylvan Gagnon; E.M.(Ted) Bilek; Lisa Podesto; Pablo Crespell

2013-01-01

Cross-laminated timber ( CLT), a new generation of engineered wood product developed initially in Europe, has been gaining increased popularity in residential and non-residential applications in several countries. Many impressive low- and mid-rise buildings built around the world using CLT showcase the many advantages this product has to offer to the construction...

Global timber investments, wood costs, regulation, and risk

Science.gov (United States)

F. Cubbage; S. Koesbandana; P Mac Donagh; R. Rubilar; G Balmelli; V. Morales Olmos; R. De La Torre; M. Murara; V.A. Hoeflich; H. Kotze; R Gonzalez; O. Carrero; G. Frey; T. Adams; J. Turner; R. Lord; J. Huang; C. MacIntyre; Kathleen McGinley; R. Abt; R. Phillips

2010-01-01

We estimated financial returns and wood production costs in 2008 for the primary timber plantation species. Excluding land costs, returns for exotic plantations in almost all of South America e Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay e were substantial. Eucalyptus species returns were generally greater than those for Pinus species in each...

Forest soil biology-timber harvesting relationships: a perspective

Science.gov (United States)

M. F. Jurgensen; M. J. Larsen; A. E. Harvey

1979-01-01

Timber harvesting has a pronounced effect on the soil microflora by wood removal and changing properties. This paper gives a perspective on soil biology-harvesting relationships with emphasis on the northern Rocky Mountain region. Of special significance to forest management operations are the effects of soil micro-organisms on: the availability of soil nutrients,...

75 FR 21577 - Rogue River-Siskiyou National Forest, Powers Ranger District, Coos County, OR; Eden Ridge Timber...

Science.gov (United States)

2010-04-26

... Plan, page C-39). Specifically for the Eden Ridge Timber Sales project, Needs include: Improvement of... District, Coos County, OR; Eden Ridge Timber Sales AGENCY: Forest Service, USDA. ACTION: Notice of intent... Forest's Probable Sale Quantity. The planning area is located approximately four (4) air miles southeast...

Profitability of timber harvesting and timber transportation enterprises

International Nuclear Information System (INIS)

Rajamaeki, J.

1996-01-01

In co-operation with the major companies contracting out forestry work and Statistics Finland, Metsaeteho carried out a project with the objective of analysing the economic profitability of timber harvesting and transportation enterprises in 1994. The calculation of profitability was based on utilisation of last livelihoods taxation data (EVR) that Statistics Finland was in possession of. The basic material comprised data that the companies contracting out forestry work had full-time entrepreneurs. There were 255 forestry machine contractor enterprises and 270 trucking enterprises. Statistics Finland was responsible for computations of the results of the project. The calculation of the indicators of profitability was based on the recommendations of Yritystutkimusneuvottelukunta, a committee looking into the functioning of enterprises. The year 1994 was a good year from the viewpoint of profitability of both forestry machine contractors as well as trucking enterprises. With full depreciations and salary adjustments attended to, both enterprise groups still showed a mean profitability of ca. 8 %. The yield of invested capital was ca. 25 %. The differences in profitability among enterprises were great in both groups and in different parts of the country

In situ assessment of structural timber elements of a historic building by infrared thermography and ultrasonic velocity

Science.gov (United States)

Kandemir-Yucel, A.; Tavukcuoglu, A.; Caner-Saltik, E. N.

2007-01-01

The infrared thermography (IRT) and the ultrasonic velocity measurements (UVM) promise to be particularly important to assess the state of deterioration and the adequacy of the boundary and microclimatic conditions for timber elements. These non-destructive methods supported by laboratory analyses of timber samples were conducted on a 13th century monument, Aslanhane Mosque in Ankara, Turkey. The combined interpretation of the results was done to assess the condition of structural timber elements in terms of their state of preservation, the dampness problems and the recent incompatible repairs affecting them. Results indicated that moist areas in the structure were associated with roof drainage problems and the repairs undertaken with cement-based mortars and plasters and oil-based paints. Juxtaposition of the IRT and UVM together with laboratory analyses was found to be useful to assess the soundness of timber, enhanced the accuracy and effectiveness of the survey and facilitated to build up the urgent and long-term conservation programs.

Development of flexural vibration inspection techniques to rapidly assess the structural health of timber bridge systems

Science.gov (United States)

Xiping Wang; James P. Wacker; Robert J. Ross; Brian K. Brashaw; Robert Vatalaro

2005-01-01

This paper describes an effort to develop a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the natural frequency of single-span timber bridges in the laboratory and field. An analytical model based on simple beam theory was proposed to represent the relationship...

26 CFR 1.631-2 - Gain or loss upon the disposal of timber under cutting contract.

Science.gov (United States)

2010-04-01

... cutting contract. 1.631-2 Section 1.631-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... loss upon the disposal of timber under cutting contract. (a) In general. (1) If an owner disposes of... deemed to be the date such timber is cut. However, if payment is made to the owner under the contract for...

Idaho's forest products industry and timber harvest, 2011

Science.gov (United States)

Eric A. Simmons; Steven W. Hayes; Todd A. Morgan; Charles E. Keegan; Chris Witt

2014-01-01

This report traces the flow of Idaho’s 2011 timber harvest through the primary industries; provides a description of the structure, capacity, and condition of Idaho’s industry; and quantifies volumes and uses of wood fiber. Historical wood products industry trends are discussed, as well as changes in harvest, production, employment, and sales.

36 CFR 223.118 - Appeal process for small business timber sale set-aside program share recomputation decisions.

Science.gov (United States)

2010-07-01

... appeal: (i) The appellant's name, mailing address, and daytime telephone number; (ii) The title or type... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Appeal process for small... FOREST SYSTEM TIMBER Timber Sale Contracts Contract Administration § 223.118 Appeal process for small...

Identification case of evidence in timber tracing of Pinus radiate, using high-resolution melting (HRM) analysis.

Science.gov (United States)

Solano, Jaime; Anabalón, Leonardo; Encina, Francisco

2016-03-01

Fast, accurate detection of plant species and their hybrids using molecular tools will facilitate assessment and monitoring of timber tracing evidence. In this study the origin of unknown pine samples is determined for a case of timber theft in the region of Araucania southern Chile. We evaluate the utility of the trnL marker region for species identification applied to pine wood based on High Resolution Melting. This efficient tracing methods can be incorporated into forestry applications such as certification of origin. The object of this work was genotype identification using high-resolution melting (HRM) and trnL approaches for Pinus radiata (Don) in timber tracing evidence. Our results indicate that trnL is a very sensitive marker for delimiting species and HRM analysis was used successfully for genotyping Pinus samples for timber tracing purposes. Genotyping samples by HRM analysis with the trnL1 approach allowed us to differentiate two wood samples from the Pinaceae family: Pinus radiata (Don) and Pseudotsuga menziesii (Mirb.) Franco. The same approach with Pinus trnL wood was not able to discriminate between samples of Pinus radiata, indicating that the samples were genetically indistinguishable, possibly because they have the same genotype at this locus. Timber tracing with HRM analysis is expected to contribute to future forest certification schemes, control of illegal trading, and molecular traceability of Pinus spp. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Essays on the economics of British Columbian timber policy

NARCIS (Netherlands)

Niquidet, Kurt

2007-01-01

This thesis examines the process of institutional change in British Columbia’s timber sector. It is composed of a series of essays which highlight the underlying political and economic factors that have shaped past and current reforms. Taking center stage in the analysis, are the resource rents

Timber beams loaded perpendicular to grain by multiple connections

NARCIS (Netherlands)

Leijten, A.J.M.; Schoenmakers, J.C.M.

2014-01-01

In timber structures, beams which are loaded perpendicular to grain by connections along the span may fail by splitting, resulting in the collapse of the beam. In the past, empirical, semi-empirical and fracture mechanical models have been developed aiming at predicting the splitting failure load.

Metals determination in wood treated by synchrotron radiation X-ray fluorescence analysis

International Nuclear Information System (INIS)

Vives, Ana Elisa Sirito de; Medeiros, Jean Gabriel da Silva; Tomazello Filho, Mario

2005-01-01

The paper describes the use of X-Ray fluorescence analysis for distribution and quantification of metals in the hardwood (Eucalyptus sp) and softwood (Pinus sp) treated with CCA (copper-chromium-arsenic). The sapwood/heartwood for hardwood sample and the growth-rings for softwood sample were analyzed. The samples were scanned in 320 mm steps in the vertical direction. For excitation of the elements a white beam synchrotron radiation of ∼ 320 x 180 mm was employed and for the X-ray detection a Si(Li) semiconductor detector. The elements K, Ca, Cr, Mn, Cu, Zn and As were determined. Fundamental parameters were used to quantify the elements concentrations. (author)

Metals determination in wood treated by synchrotron radiation X-ray fluorescence analysis

Energy Technology Data Exchange (ETDEWEB)

Vives, Ana Elisa Sirito de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Silva, Richard Maximiliano da Cunha [Centro de Energia Nuclear na Agricultura, Piracicaba, SP (Brazil)]. E-mail: maxcunha@cena.usp.br; Medeiros, Jean Gabriel da Silva; Tomazello Filho, Mario [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mail: jeangm@esalq.usp.br; mtomazel@esalq.usp.br; Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Zucchi, Orgheda Luiza Araujo Domingues [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Barroso, Regina Cely [Universidade do Estado, Rio de Janeiro, RJ (Brazil)]. E-mail: cely@uerj.br

2005-07-01

The paper describes the use of X-Ray fluorescence analysis for distribution and quantification of metals in the hardwood (Eucalyptus sp) and softwood (Pinus sp) treated with CCA (copper-chromium-arsenic). The sapwood/heartwood for hardwood sample and the growth-rings for softwood sample were analyzed. The samples were scanned in 320 mm steps in the vertical direction. For excitation of the elements a white beam synchrotron radiation of {approx} 320 x 180 mm was employed and for the X-ray detection a Si(Li) semiconductor detector. The elements K, Ca, Cr, Mn, Cu, Zn and As were determined. Fundamental parameters were used to quantify the elements concentrations. (author)

78 FR 73818 - Information Collection; Timber Sale Contract Operations and Administration

Science.gov (United States)

2013-12-09

.... Forest Service officers collect the information from contractors who may be individuals, private sector... timber and other forest products, in order to: (1) Plan and schedule contract administration workloads...

Seismic Strengthening of Carpentry Joints in Traditional Timber Structures

International Nuclear Information System (INIS)

Parisi, Maria A.; Cordie, Cinzia; Piazza, Maurizio

2008-01-01

The static and dynamic behavior of timber structures largely depends on their connections. In traditional timber construction, elements are usually connected with carpentry joints based on contact pressure and friction, often with only minor reinforcement generically intended to avoid disassembling. In current practice, interventions for the upgrading of carpentry joints are mainly based on empirical knowledge according to tradition. Often they produce a general strengthening of the connection, but are not specific for the case of seismic action. Strengthening on heuristic bases may be only partially effective or possibly disproportioned. The behavior of the carpentry joints most used in roof structures is examined. The birdsmouth joint, connecting rafters to the tie beam, has been studied first, characterizing its behavior numerically and experimentally in monotonic and cyclic conditions. Other forms of the rafter-to-tie connection, the double notch joint and the case of parallel rafters, are discussed. Some general criteria for the seismic strengthening of these joints are presented

Seismic Strengthening of Carpentry Joints in Traditional Timber Structures

Science.gov (United States)

Parisi, Maria A.; Cordié, Cinzia; Piazza, Maurizio

2008-07-01

The static and dynamic behavior of timber structures largely depends on their connections. In traditional timber construction, elements are usually connected with carpentry joints based on contact pressure and friction, often with only minor reinforcement generically intended to avoid disassembling. In current practice, interventions for the upgrading of carpentry joints are mainly based on empirical knowledge according to tradition. Often they produce a general strengthening of the connection, but are not specific for the case of seismic action. Strengthening on heuristic bases may be only partially effective or possibly disproportioned. The behavior of the carpentry joints most used in roof structures is examined. The birdsmouth joint, connecting rafters to the tie beam, has been studied first, characterizing its behavior numerically and experimentally in monotonic and cyclic conditions. Other forms of the rafter-to-tie connection, the double notch joint and the case of parallel rafters, are discussed. Some general criteria for the seismic strengthening of these joints are presented.

Simulating Harvest Schedule for Timber Management and Multipurpose Management in Teak Plantations

Directory of Open Access Journals (Sweden)

Tatang Tiryana

2016-04-01

Full Text Available Sustainable management of teak plantations in Java requires an improvement of the existing yield regulation method to optimize multiple benefits of the plantations at risk of stand destruction. This study was therefore aimed to formulate an alternative harvest scheduling model that integrates risk of stand destruction for supporting multipurpose management of teak plantations. The proposed model used a state-space planning model to simulate the dynamic of plantations due to timber harvesting and stand destruction, and then sought optimal solutions for 2 management scenarios, i.e. timber management that optimized total harvest volume and multipurpose management that optimized net present value (NPV while increasing carbon stocks. Using a case study on a typical teak plantation, this study confirmed that increasing destruction rates reduced harvest volumes, NPV, carbon stocks, and resulted in imbalanced ending age-class structures. Reducing cutting-age limit increased harvest volumes and NPV, but it also reduced carbon stocks of the plantations. Although the multipurpose management generated lower financial benefit, it maintained carbon stocks and produced better ending age-class structures compared to timber management. The proposed harvest scheduling model provides a useful planning tool for managing teak plantations.

An experimental study on damage detection of structures using a timber beam

International Nuclear Information System (INIS)

Choi, Fook Choon; Li, Jianchun; Samali, Bijan; Crews, Keith

2007-01-01

Using vibration methods for the damage detection and structural health monitoring in bridge structures is rapidly developing. However, very little work has so far been reported on timber bridges. This paper intends to address such shortcomings by experimental investigation on a timber beam using a vibration based method to detect damage. A promising damage detection algorithm based on modal strain energy was adopted and modified to locate/evaluate damage. A laboratory investigation was conducted on a timber beam inflicted with various damage scenarios using modal tests. The modal parameters obtained from the undamaged and damaged state of the test beam were used in the computation of damage index, were then applied using a damage detection algorithm utilising modal strain energy and a statistical approach to detect location of damage. A mode shape reconstruction technique was used to enhance the capability of the damage detection algorithm with limited number of sensors. The test results and analysis show that location of damage can be accurately identified with limited sensors. The modified method is less dependent on the number of modes selected and can detect damage with a higher degree of confidence

Habitat change and restoration: responses of a forest-floor mammal species to manipulations of fallen timber in floodplain forests

Directory of Open Access Journals (Sweden)

Mac Nally, R

2002-05-01

Full Text Available In forests and woodlands, fallen timber (logs and large branches is an important habitat element for many species of animals. Fallen timber has been systematically stripped in many forests, eliminating an important structural element. This study describes results of a ‘meso-scale’ experiment in which fallen timber was manipulated in a floodplain forest of the Murray River in south-eastern Australia. A thousand tons of wood were redistributed after one-year’s pre-manipulation monitoring, while a further two-year’s post-manipulation monitoring was conducted. The response of the main forest-floor small-mammal species, the Yellow-footed Antechinus Antechinus flavipes, to alterations of fallen-wood loads is documented. Results of the experiment will help to frame guidelines for fallen-timber management in these extensive floodplain forests.

Modelling the potential consequences of future worldwide biomass energy demand for the french forests and timber

International Nuclear Information System (INIS)

Buongiorno, Joseph; Raunikar, Ronald; Zhu, Shushuai

2011-01-01

This article describes an investigation conducted, using a world model for the forestry and forest-based industries, on the effects of the current unpredictable changes in worldwide demand for biomass energy on this sector in France. Two contrasting scenarios are tested. The results are commented and the potential conflict between various would uses - workable timber, industrial timber and dendro-energy - is underscored. (authors)

A Study of Bond of Structural Timber and Carbon Fiber Reinforced Polymer Plate

Directory of Open Access Journals (Sweden)

Yongtaeg LEE

2015-11-01

Full Text Available The increase of well-being culture of problem related to environmental depletion of resource is not the growing interest in timber the natural material of construction markets. Also, the perception for historic preservation has been increased in respond to heightened interest. However, it is fairly difficult for architectural properties to maintain their durability because it was made by timber construction. Preventing traditional structure from damage and structural performance reduction is paramount in maintenance problem. A number of studies of reinforced method have been conducted in order to solve such a problem. In this paper, external bonded reinforcement and near-surface mounted was used as a way to reinforce timber structure’s durability. Bond strength for specimens with different bond length was investigated. As a result showed, maximum bond strength in bond length 300 mm from all method, was found to be not increased of bond strength over the certain bond length.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9702

Form Exploration of Folded Plate Timber Structures based on Performance Criteria

DEFF Research Database (Denmark)

Falk, Andreas; Buelow, Peter Von

2011-01-01

This paper presents an explorative study on applications of cross-laminated timber (CLT) elements in shell structures. Previous studies of plate tensegrity, folded plate roofs interacting with stabilising steel-based systems and studies inspired by origami show a widening range of possibilities...... to develop timber-based shells. Steadily rising interest in rationality during pre-fabrication, transport and on-site construction in contemporary industrialised production increases the competitiveness of CLT-based elements and systems and the architectural applications are getting more common and more...... experimental. Folded plate structures which are the focus of this paper present several issues of structural importance – potential mechanisms, subdivision of surfaces etc. – and the hereby presented study aims at exploring developed typologies, using computer tools for developed optimisation procedures...

Timber resource of Michigan's Southern Lower Peninsula Unit, 1980.

Science.gov (United States)

Jerold T. Hahn

1982-01-01

The fourth inventory of the timber resource of Michigan's Southern Lower Peninsula Survey Unit shows a 12% decline in commercial forest area and a 26% gain in growing-stock volume between 1966 and 1980. Presented are highlights and statistics on area, volume, growth, mortality, removals, utilization, and biomass.

36 CFR 261.6 - Timber and other forest products.

Science.gov (United States)

2010-07-01

... such product is identified as required in such permit or contract. (f) Selling or exchanging any timber... 74 FR 26091, June 1, 2009, the amendment was delayed indefinitely. For the convenience of the user..., memorandum of agreement, memorandum of understanding, or personal-use authorization (f) Selling or exchanging...

Gender analysis of non-timber forest products (NTFPs) collection ...

African Journals Online (AJOL)

Millions of people, especially those living in rural areas in developing countries collect Non-Timber Forest products (NTFPs) daily. Women are known to play a prominent role in forestry and agricultural production in Nigeria despite not been captured as economically productive. This work looked into gender dimension ...

Efficiency and precision for estimating timber and non-timber attributes using Landsat-based stratification methods in two-phase sampling in northwest California

Science.gov (United States)

Antti T. Kaartinen; Jeremy S. Fried; Paul A. Dunham

2002-01-01

Three Landsat TM-based GIS layers were evaluated as alternatives to conventional, photointerpretation-based stratification of FIA field plots. Estimates for timberland area, timber volume, and volume of down wood were calculated for California's North Coast Survey Unit of 2.5 million hectares. The estimates were compared on the basis of standard errors,...

Analysis of the Strength of Timber and Glulam Timber Beams with Steel Reinforcement

Directory of Open Access Journals (Sweden)

Arie Putra Usman

2015-12-01

Full Text Available Indonesia is a tropical country with abundant tropical timber that can be used as a building material. Wood is a renewable material, thus making it an environmentally friendly construction material. However, the dimensional limitations of solid wood may pose problems in structural constructions. Wood material also has some disadvantages, such as brittle failure. However, the ductility of wood can be increased because of plasticity occurring in the compression zone. Wood material with good ductility can be obtained by reinforcing it in the tensile zone. This study is about the strength of wood material for use as a material for structural elements. Based on the analytical findings, the bending capacity of wood can be improved by adding reinforcements to the tensile zone.

structural reliability of the nigerian grown abura timber bridge beam

African Journals Online (AJOL)

ENGR. J. I. AGUWA

2013-07-02

Jul 2, 2013 ... Structural analysis and deterministic design of a timber bridge beam using the Nigerian ... practice especially when it involves naturally occuring materials .... the beam due to distributed loads is; from [15]. (4). It is assumed that ...

Empowering Women and Ethnic Minority Groups to Collectively Market non Timber Forest Products from Community Forests in Cameroon

NARCIS (Netherlands)

Eijnatten, van Judith; Mala, William Armand; Ingram, V.J.; Belibi, M.B.

2016-01-01

Community forestry (CF) was introduced in Cameroon in 1994 as a way to reduce poverty and enhance sustainable forest management. CF activities have primarily focused on timber exploitation rather than non-timber forest product (NTFP) collection processing or marketing. The study reports on a two

2nd International Conference on Historic Earthquake-Resistant Timber Frames in the Mediterranean Area

CERN Document Server

Machado, José; Costa, Alfredo; Candeias, Paulo; Ruggieri, Nicola; Catarino, José

2016-01-01

This book presents a selection of the best papers from the HEaRT 2015 conference, held in Lisbon, Portugal, which provided a valuable forum for engineers and architects, researchers and educators to exchange views and findings concerning the technological history, construction features and seismic behavior of historical timber-framed walls in the Mediterranean countries. The topics covered are wide ranging and include historical aspects and examples of the use of timber-framed construction systems in response to earthquakes, such as the gaiola system in Portugal and the Bourbon system in southern Italy; interpretation of the response of timber-framed walls to seismic actions based on calculations and experimental tests; assessment of the effectiveness of repair and strengthening techniques, e.g., using aramid fiber wires or sheets; and modelling analyses. In addition, on the basis of case studies, a methodology is presented that is applicable to diagnosis, strengthening and improvement of seismic performance ...

Timbered masonry for earthquake resistance in Europe

OpenAIRE

Dutu, A.; Gomes Ferreira, J.; Guerreiro, L.; Branco, F.; Gonçalves, A. M.

2012-01-01

Europe is a continent that is subject to significant seismic activity. Thus, the buildings’ seismic behaviour must be analysed, including not only the new structures, designed under more rigorous codes, but also older ones. This article examines a traditional type of building that uses timber frame/masonry, which is found in Portugal, Turkey, France, England, Greece, Romania, Italy, Spain, Germany and Scandinavia. Although the structures differ in terms of construction details, their struc...

Timbered masonry for earthquake resistance in Europe

OpenAIRE

Dutu, A.; Gomes Ferreira, J.; Guerreiro, L.; Branco, F.; Gonçalves, A. M.

2012-01-01

Europe is a continent that is subject to significant seismic activity. Thus, the buildings’ seismic behaviour must be analysed, including not only the new structures, designed under more rigorous codes, but also older ones. This article examines a traditional type of building that uses timber frame/masonry, which is found in Portugal, Turkey, France, England, Greece, Romania, Italy, Spain, Germany and Scandinavia. Although the structures differ in terms of construction details, their str...

Non-timber forest products in sustainable forest management

Science.gov (United States)

James L. Chamberlain; A.L. Hammett; Philip A. Araman

2001-01-01

The forests of Southern United States are the source of many non-timber forest products (NTFPs). The collection, trade and use of these products have been important to rural economies since Europeans settled in this country. At the same time the plants from which these products originate are crucial to healthy ecosystems. Over the last decade, the market demand and the...

The supply and demand situation for oak timber

Science.gov (United States)

Kenneth L. Quigley

1971-01-01

Twenty oak species in the eastern United States account for one-third of the hardwood sawtimber volume and almost 10 percent of both hardwood and softwood growing-stock volume. The oak-hickory and oak-pine forest types occupy about 38 percent of the forest land in the eastern United States. Oak timber volume is increasing. Annual growth exceeds annual removals by about...

Timber market research, private forests, and policy rhetoric

Science.gov (United States)

David N. Wear; Jeffrey P. Prestemon

2004-01-01

The development of the profession and practice of forestry in the United States can be linked to urgent concerns regarding timber shortages in the late 19th century (Williams 1989). These were based largely on perceived failures of forest landowners to protect or invest enough in the productive capacity of their forests (Manthy 1977). The South, as the only major...

Timber resource statistics for Oregon, January 1, 1973.

Science.gov (United States)

Patricia M. Bassett; Grover A. Choate

1974-01-01

Timber resource statistics as of January 1, 1973, for the State of Oregon show total land area, commercial timberland area, and growing stock and sawtimber inventory volumes by county and owner group. Growth and removals are shown by Forest Survey inventory unit for 1972. Each National Forest is updated to January 1, 1973, as well as each Bureau of Land Management...

Emissions from prescribed burning of timber slash piles in Oregon.

Science.gov (United States)

Emissions from burning piles of post-harvest timber slash (Douglas fir) in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matte...

Temperature development and sterilization of red pine poles during CCA treatment, elevated temperature fixation and drying

Energy Technology Data Exchange (ETDEWEB)

Cooper, P.; Albright, M.; Srinivasan, U.; Ung, A. [New Brunswick Univ., Fredericton, NB (Canada). Wood Science and Technology Centre

2002-07-01

The application of chromated copper arsenate (CCA) treatment and fixation and drying under the conditions of the study to large red pine poles left for an air seasoning period of 10 months in Quebec, Canada progressively reduced the number of micro-organisms present. A large number of microfungi isolations were effected before the treatment from the sapwood and heartwood of all poles and wood decay fungi on 8 selected poles from the 20 test poles. They originated from the sapwood zone. A reduction of approximately 50 per cent in the number of microfungi isolated from the sapwood was noted after the CCA treatment. In the case of 9 of 30 poles, basidiomycetes were isolated after treatment primarily from the untreated heartwood. There were a few instances where basidiomycetes were isolated from unpenetrated sapwood (wet pockets). Temperatures of 55 to 60 degrees Celsius were achieved under moderate temperature fixation schedules (20 hours) for approximately 5 hours at full sapwood depth. Only by the end of the schedule was a temperature of 55 degrees celsius achieved at the centre of the poles. Most of the microfungi were eliminated by this temperature regime. Trichoderma was eliminated, and only one isolation of basidiomycetes was left from the heartwood of one pole. Temperatures of 55 to 60 degrees Celsius were achieved in the wood core for 9 to 10 days during kiln drying. No basidiomycete isolations remained after this exposure. In several of the poles, there was evidence of Paecilomyces variotii, a thermo-tolerant species and a number of species of Penicillium moulds. It was concluded that there was a negligible probability of decay fungi surviving the sequence of processes as described, given the effectiveness of the fixation exposure and the higher wood temperatures sustained for longer periods. 16 refs., 5 tabs., 2 figs.

36 CFR 223.201 - Limitations on unprocessed timber harvested in Alaska.

Science.gov (United States)

2010-07-01

... Conservation and Shortage Relief Act of 1990 Program § 223.201 Limitations on unprocessed timber harvested in... or serious deterioration of logs unsalable locally because of an unforeseen loss of market, (c...

50 CFR 36.15 - Subsistence uses of timber and plant material.

Science.gov (United States)

2010-10-01

... appropriate subsistence uses, such as firewood or house logs, may be permitted in Alaska National Wildlife... timber for firewood, shall be allowed without a permit. (c)(1) Notwithstanding any other provision of...

Marketing of Non-Timber Forest Products in Kajola Local ...

African Journals Online (AJOL)

Marketing of Non-Timber Forest Products in Kajola Local Government Area of Oyo State, Nigeria. ... International Journal of Tropical Agriculture and Food Systems ... The results of the marketing margin reveal that charcoal commanded the highest margin of ₦2500, followed by bush meat (₦300), while wrapping had the ...

Modeling ground-based timber harvesting systems using computer simulation

Science.gov (United States)

Jingxin Wang; Chris B. LeDoux

2001-01-01

Modeling ground-based timber harvesting systems with an object-oriented methodology was investigated. Object-oriented modeling and design promote a better understanding of requirements, cleaner designs, and better maintainability of the harvesting simulation system. The model developed simulates chainsaw felling, drive-to-tree feller-buncher, swing-to-tree single-grip...

Process and device for producing a timber gear case for tunnels and mines

Energy Technology Data Exchange (ETDEWEB)

Foik, A

1977-09-08

A device is described for producing a timber gear case for tunnels and mines. Plank shaped pillars, partly overlapping one another are driven in parallel planes at an angle to the tunnel axis, close together and advancing relative to the face. The pillars are taken through supports erected one after the other in the longitudinal direction of the tunnel, and are supported. The process can be extended by producing a timber gear case to secure any type of underground space. The process produces further mechanisation of tunnelling and mining and also ensures greater safety for the miners.

Calcification rates of crustose coralline algae (CCA) derived from Calcification Accretion Units (CAUs) deployed at coral reef sites in Batangas, Philippines in 2012 and recovered in 2015 (NCEI Accession 0162831)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Laboratory experiments reveal calcification rates of crustose coralline algae (CCA) are strongly correlated to seawater aragonite saturation state. Predictions of...

Condition Assessment of the Timber Structures of a Century-Old Industrial Building Using a Nondestructive Inspection Procedure

Science.gov (United States)

Xiping Wang; Marko Teder; James Wacker

2013-01-01

This paper reports an in situ inspection project conducted on heavy timber structures of a century-old industrial building at a paper manufacturing facility. A nondestructive inspection procedure was employed to evaluate the true condition of the heavy timbers that serve as the main framing structure of the building. The on-site investigation involved monitoring of the...

Assessments of the market prospects for Myanmar timber

International Nuclear Information System (INIS)

Tin-Maung-Win

2001-08-01

Myanmar has been exporting teak and hardwood logs and conversions for a long time. It is found that there are three types of market situations with regard to logs and conversions. They are: situation that the demand of the market is strong; situation that the market has just picked up; situation that the demand is sluggish. Countries where the demand is strong are India, Thailand and Malaysia. Countries where the market is picking up are Singapore, PRC and the Middle East. Similarly, Europe's market is on the rise. Japan, Korea, Hong Kong and Pakistan markets are sluggish temporarily. North America's market can be said to be sluggish too. It is found that Australia has not been buying timber directly from Myanmar for the last few years and that it may not be in a position to buy Myanmar teak voluminously in the near future either. This paper is therefore a report focused on Myanmar Timber Enterprises' endeavour to earn foreign exchange in US Dollars and its assessment and evaluation of the market. The international market situation is studied and each country's situation focused on and presented. (author)

75 FR 63419 - Surety Bond Guarantee Program; Timber Sales

Science.gov (United States)

2010-10-15

... with the contract terms. 36 CFR 223.35. Generally, the Performance Bond, as defined in 13 CFR 115.10, ensures that the Principal, as defined in 13 CFR 115.10, complies with all contract terms and conditions... timber sale contracts awarded by the Federal Government or other public or private landowners. DATES...

Forest ecosystem services: Provisioning of non-timber forest products

Science.gov (United States)

James L. Chamberlain; Gregory E. Frey; C. Denise Ingram; Michael G. Jacobson; Cara Meghan Starbuck Downes

2017-01-01

The purpose of this chapter is to describe approaches to calculate a conservative and defensible estimate of the marginal value of forests for non-timber forest products (NTFPs). 'Provisioning" is one of four categories of benefits, or services that ecosystems provide to humans and was described by the Millennium Ecosystem Assessment as 'products...

A Numerical Analysis of the Resistance and Stiffness of the Timber and Concrete Composite Beam

Science.gov (United States)

Szumigała, Ewa; Szumigała, Maciej; Polus, Łukasz

2015-03-01

The article presents the results of a numerical analysis of the load capacity and stiffness of the composite timber and concrete beam. Timber and concrete structures are relatively new, they have not been thoroughly tested and they are rarely used because of technological constraints. One of the obstacles to using them is difficulty with finding a method which would allow successful cooperation between concrete and timber, which has been proposed by the authors of the present article. The modern idea of sustainable construction design requires the use of new more environmentally-friendly solutions. Wood as an ecological material is easily accessible, less energy-consuming, and under certain conditions more corrosion-resistant than steel. The analysis presented in the article showed that cooperation between a wooden beam and a concrete slab on profiled steel sheeting is possible. The analysed composite beam has a greater load capacity and stiffness than the wooden beam.