WorldWideScience

Sample records for maximum allowable timber

  1. Maximum allowable load on wheeled mobile manipulators

    International Nuclear Information System (INIS)

    Habibnejad Korayem, M.; Ghariblu, H.

    2003-01-01

    This paper develops a computational technique for finding the maximum allowable load of mobile manipulator during a given trajectory. The maximum allowable loads which can be achieved by a mobile manipulator during a given trajectory are limited by the number of factors; probably the dynamic properties of mobile base and mounted manipulator, their actuator limitations and additional constraints applied to resolving the redundancy are the most important factors. To resolve extra D.O.F introduced by the base mobility, additional constraint functions are proposed directly in the task space of mobile manipulator. Finally, in two numerical examples involving a two-link planar manipulator mounted on a differentially driven mobile base, application of the method to determining maximum allowable load is verified. The simulation results demonstrates the maximum allowable load on a desired trajectory has not a unique value and directly depends on the additional constraint functions which applies to resolve the motion redundancy

  2. 49 CFR 230.24 - Maximum allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

  3. 32 CFR 842.35 - Depreciation and maximum allowances.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Depreciation and maximum allowances. 842.35... LITIGATION ADMINISTRATIVE CLAIMS Personnel Claims (31 U.S.C. 3701, 3721) § 842.35 Depreciation and maximum allowances. The military services have jointly established the “Allowance List-Depreciation Guide” to...

  4. Scientific substantination of maximum allowable concentration of fluopicolide in water

    Directory of Open Access Journals (Sweden)

    Pelo I.М.

    2014-03-01

    Full Text Available In order to substantiate fluopicolide maximum allowable concentration in the water of water reservoirs the research was carried out. Methods of study: laboratory hygienic experiment using organoleptic and sanitary-chemical, sanitary-toxicological, sanitary-microbiological and mathematical methods. The results of fluopicolide influence on organoleptic properties of water, sanitary regimen of reservoirs for household purposes were given and its subthreshold concentration in water by sanitary and toxicological hazard index was calculated. The threshold concentration of the substance by the main hazard criteria was established, the maximum allowable concentration in water was substantiated. The studies led to the following conclusions: fluopicolide threshold concentration in water by organoleptic hazard index (limiting criterion – the smell – 0.15 mg/dm3, general sanitary hazard index (limiting criteria – impact on the number of saprophytic microflora, biochemical oxygen demand and nitrification – 0.015 mg/dm3, the maximum noneffective concentration – 0.14 mg/dm3, the maximum allowable concentration - 0.015 mg/dm3.

  5. Maximum allowable heat flux for a submerged horizontal tube bundle

    International Nuclear Information System (INIS)

    McEligot, D.M.

    1995-01-01

    For application to industrial heating of large pools by immersed heat exchangers, the socalled maximum allowable (or open-quotes criticalclose quotes) heat flux is studied for unconfined tube bundles aligned horizontally in a pool without forced flow. In general, we are considering boiling after the pool reaches its saturation temperature rather than sub-cooled pool boiling which should occur during early stages of transient operation. A combination of literature review and simple approximate analysis has been used. To date our main conclusion is that estimates of q inch chf are highly uncertain for this configuration

  6. 49 CFR 192.619 - Maximum allowable operating pressure: Steel or plastic pipelines.

    Science.gov (United States)

    2010-10-01

    ... plastic pipelines. 192.619 Section 192.619 Transportation Other Regulations Relating to Transportation... Operations § 192.619 Maximum allowable operating pressure: Steel or plastic pipelines. (a) No person may operate a segment of steel or plastic pipeline at a pressure that exceeds a maximum allowable operating...

  7. Pressurizer /Auxiliary Spray Piping Stress Analysis For Determination Of Lead Shielding Maximum Allow Able Load

    International Nuclear Information System (INIS)

    Setjo, Renaningsih

    2000-01-01

    Piping stress analysis for PZR/Auxiliary Spray Lines Nuclear Power Plant AV Unit I(PWR Type) has been carried out. The purpose of this analysis is to establish a maximum allowable load that is permitted at the time of need by placing lead shielding on the piping system on class 1 pipe, Pressurizer/Auxiliary Spray Lines (PZR/Aux.) Reactor Coolant Loop 1 and 4 for NPP AV Unit one in the mode 5 and 6 during outage. This analysis is intended to reduce the maximum amount of radiation dose for the operator during ISI ( In service Inspection) period.The result shown that the maximum allowable loads for 4 inches lines for PZR/Auxiliary Spray Lines is 123 lbs/feet

  8. 49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

    Science.gov (United States)

    2010-10-01

    ... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

  9. 49 CFR 192.623 - Maximum and minimum allowable operating pressure; Low-pressure distribution systems.

    Science.gov (United States)

    2010-10-01

    ... distribution systems. (a) No person may operate a low-pressure distribution system at a pressure high enough to...) No person may operate a low pressure distribution system at a pressure lower than the minimum... 49 Transportation 3 2010-10-01 2010-10-01 false Maximum and minimum allowable operating pressure...

  10. The Maximum Free Magnetic Energy Allowed in a Solar Active Region

    Science.gov (United States)

    Moore, Ronald L.; Falconer, David A.

    2009-01-01

    Two whole-active-region magnetic quantities that can be measured from a line-of-sight magnetogram are (sup L) WL(sub SG), a gauge of the total free energy in an active region's magnetic field, and sup L(sub theta), a measure of the active region's total magnetic flux. From these two quantities measured from 1865 SOHO/MDI magnetograms that tracked 44 sunspot active regions across the 0.5 R(sub Sun) central disk, together with each active region's observed production of CMEs, X flares, and M flares, Falconer et al (2009, ApJ, submitted) found that (1) active regions have a maximum attainable free magnetic energy that increases with the magnetic size (sup L) (sub theta) of the active region, (2) in (Log (sup L)WL(sub SG), Log(sup L) theta) space, CME/flare-productive active regions are concentrated in a straight-line main sequence along which the free magnetic energy is near its upper limit, and (3) X and M flares are restricted to large active regions. Here, from (a) these results, (b) the observation that even the greatest X flares produce at most only subtle changes in active region magnetograms, and (c) measurements from MSFC vector magnetograms and from MDI line-of-sight magnetograms showing that practically all sunspot active regions have nearly the same area-averaged magnetic field strength: =- theta/A approximately equal to 300 G, where theta is the active region's total photospheric flux of field stronger than 100 G and A is the area of that flux, we infer that (1) the maximum allowed ratio of an active region's free magnetic energy to its potential-field energy is 1, and (2) any one CME/flare eruption releases no more than a small fraction (less than 10%) of the active region's free magnetic energy. This work was funded by NASA's Heliophysics Division and NSF's Division of Atmospheric Sciences.

  11. The maximum allowable temperature of zircaloy-2 fuel cladding under dry storage conditions

    International Nuclear Information System (INIS)

    Mayuzumi, M.; Yoshiki, S.; Yasuda, T.; Nakatsuka, M.

    1990-09-01

    Japan plans to reprocess and reutilise the spent nuclear fuel from nuclear power generation. However, the temporary storage of spent fuel is assuming increasing importance as a means of ensuring flexibility in the nuclear fuel cycle. Our investigations of various methods of storage have shown that casks are the most suitable means of storing small quantities of spent fuel of around 500 t, and research and development are in progress to establish dry storage technology for such casks. The soundness of fuel cladding is being investigated. The most important factor in evaluating soundness in storage under inert gas as currently envisaged is creep deformation and rupture, and a number of investigations have been made of the creep behaviour of cladding. The present study was conducted on the basis of existing in-house results in collaboration with Nippon Kakunenryo Kaihatsu KK (Nippon Nuclear Fuel Department Co.), which has hot lab facilities. Tests were run on the creep deformation behaviour of irradiated cladding, and the maximum allowable temperature during dry storage was investigated. (author)

  12. Estimation of Maximum Allowable PV Connection to LV Residential Power Networks

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

    2011-01-01

    Maximum photovoltaic (PV) hosting capacity of low voltage (LV) power networks is mainly restricted by either thermal limits of network components or grid voltage quality resulted from high penetration of distributed PV systems. This maximum hosting capacity may be lower than the available solar...... potential of geographic area due to power network limitations even though all rooftops are fully occupied with PV modules. Therefore, it becomes more of an issue to know what exactly limits higher PV penetration level and which solutions should be engaged efficiently such as over sizing distribution...

  13. ABOUT RATIONING MAXIMUM ALLOWABLE DEFECT DEPTH ON THE SURFACE OF STEEL BILLETS IN PRODUCTION OF HOT-ROLLED STEEL

    Directory of Open Access Journals (Sweden)

    PARUSOV E. V.

    2017-01-01

    Full Text Available Formulation of the problem. Significant influence on the quality of rolled steel have various defects on its surface, which in its turn inherited from surface defects of billet and possible damage to the surface of rolled steel in the rolling mill line. One of the criteria for assessing the quality indicators of rolled steel is rationing of surface defects [1; 2; 3; 6; 7]. Current status of the issue. Analyzing the different requirements of regulations to the surface quality of the rolled high-carbon steels, we can conclude that the maximum allowable depth of defects on the surface of billet should be in the range of 2.0...5.0 mm (depending on the section of the billet, method of its production and further the destination Purpose. Develop a methodology for calculating the maximum allowable depth of defects on the steel billet surface depending on the requirements placed on the surface quality of hot-rolled steel. Results. A simplified method of calculation, allowing at the rated depth of defects on the surface of the hot-rolled steel to make operatively calculation of the maximum allowable depth of surface defects of steel billets before heating the metal in the heat deformation was developed. The findings shows that the maximum allowable depth of surface defects is reduced with increasing diameter rolled steel, reducing the initial section steel billet and degrees of oxidation of the metal in the heating furnace.

  14. 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.

  15. Accurate nonlinear modeling for flexible manipulators using mixed finite element formulation in order to obtain maximum allowable load

    International Nuclear Information System (INIS)

    Esfandiar, Habib; KoraYem, Moharam Habibnejad

    2015-01-01

    In this study, the researchers try to examine nonlinear dynamic analysis and determine Dynamic load carrying capacity (DLCC) in flexible manipulators. Manipulator modeling is based on Timoshenko beam theory (TBT) considering the effects of shear and rotational inertia. To get rid of the risk of shear locking, a new procedure is presented based on mixed finite element formulation. In the method proposed, shear deformation is free from the risk of shear locking and independent of the number of integration points along the element axis. Dynamic modeling of manipulators will be done by taking into account small and large deformation models and using extended Hamilton method. System motion equations are obtained by using nonlinear relationship between displacements-strain and 2nd PiolaKirchoff stress tensor. In addition, a comprehensive formulation will be developed to calculate DLCC of the flexible manipulators during the path determined considering the constraints end effector accuracy, maximum torque in motors and maximum stress in manipulators. Simulation studies are conducted to evaluate the efficiency of the method proposed taking two-link flexible and fixed base manipulators for linear and circular paths into consideration. Experimental results are also provided to validate the theoretical model. The findings represent the efficiency and appropriate performance of the method proposed.

  16. Accurate nonlinear modeling for flexible manipulators using mixed finite element formulation in order to obtain maximum allowable load

    Energy Technology Data Exchange (ETDEWEB)

    Esfandiar, Habib; KoraYem, Moharam Habibnejad [Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2015-09-15

    In this study, the researchers try to examine nonlinear dynamic analysis and determine Dynamic load carrying capacity (DLCC) in flexible manipulators. Manipulator modeling is based on Timoshenko beam theory (TBT) considering the effects of shear and rotational inertia. To get rid of the risk of shear locking, a new procedure is presented based on mixed finite element formulation. In the method proposed, shear deformation is free from the risk of shear locking and independent of the number of integration points along the element axis. Dynamic modeling of manipulators will be done by taking into account small and large deformation models and using extended Hamilton method. System motion equations are obtained by using nonlinear relationship between displacements-strain and 2nd PiolaKirchoff stress tensor. In addition, a comprehensive formulation will be developed to calculate DLCC of the flexible manipulators during the path determined considering the constraints end effector accuracy, maximum torque in motors and maximum stress in manipulators. Simulation studies are conducted to evaluate the efficiency of the method proposed taking two-link flexible and fixed base manipulators for linear and circular paths into consideration. Experimental results are also provided to validate the theoretical model. The findings represent the efficiency and appropriate performance of the method proposed.

  17. 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....

  18. 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...

  19. 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...

  20. Effect of a therapeutic maximum allowable cost (MAC) program on the cost and utilization of proton pump inhibitors in an employer-sponsored drug plan in Canada.

    Science.gov (United States)

    Mabasa, Vincent H; Ma, Johnny

    2006-06-01

    Therapeutic maximum allowable cost (MAC) is a managed care intervention that uses reference pricing in a therapeutic class or category of drugs or an indication (e.g., heartburn). Therapeutic MAC has not been studied in Canada or the United States. The proton pump inhibitor (PPI) rabeprazole was used as the reference drug in this therapeutic MAC program based on prices for PPIs in the province of Ontario. No PPI is available over the counter in Canada. To evaluate the utilization and anticipated drug cost savings for PPIs in an employer-sponsored drug plan in Canada that implemented a therapeutic MAC program for PPIs. An employer group with an average of 6,300 covered members, which adopted the MAC program for PPIs in June 2003, was compared with a comparison group comprising the book of business throughout Canada (approximately 5 million lives) without a PPI MAC program (non-MAC group). Pharmacy claims for PPIs were identified using the first 6 characters of the generic product identifier (GPI 492700) for a 36-month period from June 1, 2002, through May 31, 2005. The primary comparison was the year prior to the intervention (from June 1, 2002, through May 31, 2003) and the first full year following the intervention (June 1, 2004, through May 31, 2005). Drug utilization was evaluated by comparing the market share of each of the PPIs for the 2 time periods and by the days of PPI therapy per patient per year (PPPY) and days of therapy per prescription (Rx). Drug cost was defined as the cost of the drug (ingredient cost), including allowable provincial pharmacy markup but excluding pharmacy dispense fee. Cost savings were calculated from the allowed drug cost per claim, allowed cost per day, and allowed cost PPPY. (All amounts are in Canadian dollars.) The MAC intervention group experienced an 11.7% reduction in the average cost per day of PPI drug therapy, from 2.14 US dollars in the preperiod to 1.89 US dollars in the postperiod, compared with a 3.7% reduction in

  1. 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.

  2. 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.

  3. 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)

  4. Recommendation of maximum allowable noise levels for offshore wind power systems; Empfehlung von Laermschutzwerten bei der Errichtung von Offshore-Windenergieanlagen (OWEA)

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Stefanie [Umweltbundesamt, Dessau-Rosslau (Germany). Fachgebiet II 2.3

    2011-05-15

    When offshore wind farms are constructed, every single pile is hammered into the sediment by a hydraulic hammer. Noise levels at Horns Reef wind farm were in the range of 235 dB. The noise may cause damage to the auditory system of marine mammals. The Federal Environmental Office therefore recommends the definition of maximum permissible noise levels. Further, care should be taken that no marine mammals are found in the immediate vicinity of the construction site. (AKB)

  5. 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...

  6. 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 ...

  7. 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.

  8. 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

  9. 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

  10. 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...

  11. Learning maximum entropy models from finite-size data sets: A fast data-driven algorithm allows sampling from the posterior distribution.

    Science.gov (United States)

    Ferrari, Ulisse

    2016-08-01

    Maximum entropy models provide the least constrained probability distributions that reproduce statistical properties of experimental datasets. In this work we characterize the learning dynamics that maximizes the log-likelihood in the case of large but finite datasets. We first show how the steepest descent dynamics is not optimal as it is slowed down by the inhomogeneous curvature of the model parameters' space. We then provide a way for rectifying this space which relies only on dataset properties and does not require large computational efforts. We conclude by solving the long-time limit of the parameters' dynamics including the randomness generated by the systematic use of Gibbs sampling. In this stochastic framework, rather than converging to a fixed point, the dynamics reaches a stationary distribution, which for the rectified dynamics reproduces the posterior distribution of the parameters. We sum up all these insights in a "rectified" data-driven algorithm that is fast and by sampling from the parameters' posterior avoids both under- and overfitting along all the directions of the parameters' space. Through the learning of pairwise Ising models from the recording of a large population of retina neurons, we show how our algorithm outperforms the steepest descent method.

  12. 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 ...

  13. 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...

  14. SU-G-TeP1-01: A Simulation Study to Investigate Maximum Allowable Deformations of Implant Geometry Before Plan Objectives Are Violated in Prostate HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Babier, A [Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, Ontario (Canada); Joshi, C [Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, Ontario (Canada); Cancer Center of Southeastern Ontario, Kingston General Hospital, Kingston, Ontario (Canada)

    2016-06-15

    Purpose: In prostate HDR brachytherapy dose distributions are highly sensitive to changes in prostate volume and catheter displacements. We investigate the maximum deformations in implant geometry before planning objectives are violated. Methods: A typical prostate Ir-192 HDR brachytherapy reference plan was calculated on the Oncentra planning system, which used CT images from a tissue equivalent prostate phantom (CIRS Model 053S) embedded inside a pelvis wax phantom. The prostate was deformed and catheters were displaced in simulations using a code written in MATLAB. For each deformation dose distributions were calculated, based on TG43 methods, using the MATLAB code. The calculations were validated through comparison with Oncentra calculations for the reference plan, and agreed within 0.12%SD and 0.3%SD for dose and volume, respectively. Isotropic prostate volume deformations of up to +34% to −27% relative to its original volume, and longitudinal catheter displacements of 7.5 mm in superior and inferior directions were simulated. Planning objectives were based on American Brachytherapy Society guidelines for prostate and urethra volumes. A plan violated the planning objectives when less than 90% of the prostate volume received the prescribed dose or higher (V{sub 100}), or the urethral volume receiving 125% of prescribed dose or higher was more than 1 cc (U{sub 125}). Lastly, the dose homogeneity index (DHI=1-V{sub 150}/V{sub 100}) was evaluated; a plan was considered sub-optimal when the DHI fell below 0.62. Results and Conclusion: Planning objectives were violated when the prostate expanded by 10.7±0.5% or contracted by 11.0±0.2%; objectives were also violated when catheters were displaced by 4.15±0.15 mm and 3.70±0.15 mm in the superior and inferior directions, respectively. The DHI changes did not affect the plan optimality, except in the case of prostate compression. In general, catheter displacements have a significantly larger impact on plan

  15. 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.

  16. 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.

  17. The Application of an Army Prospective Payment Model Structured on the Standards Set Forth by the CHAMPUS Maximum Allowable Charges and the Center for Medicare and Medicaid Services: An Academic Approach

    Science.gov (United States)

    2005-04-29

    To) 29-04-2005 Final Report July 2004 to July 2005 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER The appli’eation of an army prospective payment model structured...Z39.18 Prospective Payment Model 1 The Application of an Army Prospective Payment Model Structured on the Standards Set Forth by the CHAMPUS Maximum...Health Care Administration 20060315 090 Prospective Payment Model 2 Acknowledgments I would like to acknowledge my wife, Karen, who allowed me the

  18. 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....

  19. 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

  20. 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...

  1. 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....

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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

  12. 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

  13. 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...

  14. 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....

  15. 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...

  16. 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...

  17. 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

  18. 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...

  19. 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....

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. 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.

  5. Projecting southern timber supply for multiple products by subregion

    Science.gov (United States)

    Robert C. Abt; Frederick W. Cubbage; Karen L. Abt

    2009-01-01

    While timber supply modeling has been of importance in the wood-producing regions of the United States for decades, it is only more recently that the technology and data have allowed disaggregation of supply and demand to substate regions, including product specific breakdowns and endogenous land use and plantation changes. Using southwide data and an economic supply...

  6. CHILD ALLOWANCE

    CERN Multimedia

    Human Resources Division

    2001-01-01

    HR Division wishes to clarify to members of the personnel that the allowance for a dependent child continues to be paid during all training courses ('stages'), apprenticeships, 'contrats de qualification', sandwich courses or other courses of similar nature. Any payment received for these training courses, including apprenticeships, is however deducted from the amount reimbursable as school fees. HR Division would also like to draw the attention of members of the personnel to the fact that any contract of employment will lead to the suppression of the child allowance and of the right to reimbursement of school fees.

  7. 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.

  8. 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.

  9. 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...

  10. 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...

  11. timber for structural use

    African Journals Online (AJOL)

    HOD

    specimens were prepared for determination of their strength properties using a ... The physical and mechanical properties of wood vary ..... of length 300mm, breadth 25mm and depth ... In (8), F is the maximum load applied, a is the distance.

  12. 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

  13. 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...

  14. 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...

  15. 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.

  16. 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

  17. 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...

  18. Regulatory assessment with regulatory flexibility analysis : draft regulatory evaluation - Notice of Proposed Rulemaking -- Pipeline Safety : safety standards for increasing the maximum allowable operating pressure for natural gas transmission pipelines.

    Science.gov (United States)

    2008-02-01

    The Pipeline and Hazardous Materials Safety Administration (PHMSA) is proposing changes to the Federal pipeline safety regulations in 49 CFR Part 192, which cover the transportation of natural gas by pipeline. Specifically, PHMSA proposes allowing na...

  19. 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.

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. 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.

  8. 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....

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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

  18. 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...

  19. 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.

  20. 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...

  1. 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.

  2. 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...

  3. 78 FR 67465 - Loan Guaranty: Maximum Allowable Attorney Fees

    Science.gov (United States)

    2013-11-12

    ... foreclosure attorney fee. This fee recognizes the additional work required to resume the foreclosure action, while also accounting for the expectation that some work from the previous action may be utilized in... for legal fees in connection with the termination of single-family housing loans, including...

  4. 10 CFR 800.200 - Maximum loan; allowable costs.

    Science.gov (United States)

    2010-01-01

    ... Energy DEPARTMENT OF ENERGY LOANS FOR BID OR PROPOSAL PREPARATION BY MINORITY BUSINESS ENTERPRISES... cost principles of the Federal Procurement Regulation (41 CFR Ch. 1, 1-15.205-3) and DOE Procurement..., but are not limited to: (1) Bid bond premiums. (2) Financial, accounting, legal, engineering and other...

  5. Forest bat population dynamics over 14 years at a climate refuge: Effects of timber harvesting and weather extremes.

    Science.gov (United States)

    Law, Bradley S; Chidel, Mark; Law, Peter R

    2018-01-01

    Long-term data are needed to explore the interaction of weather extremes with habitat alteration; in particular, can 'refugia' buffer population dynamics against climate change and are they robust to disturbances such as timber harvesting. Because forest bats are good indicators of ecosystem health, we used 14 years (1999-2012) of mark-recapture data from a suite of small tree-hollow roosting bats to estimate survival, abundance and body condition in harvested and unharvested forest and over extreme El Niño and La Niña weather events in southeastern Australia. Trapping was replicated within an experimental forest, located in a climate refuge, with different timber harvesting treatments. We trapped foraging bats and banded 3043 with a 32% retrap rate. Mark-recapture analyses allowed for dependence of survival on time, species, sex, logging treatment and for transients. A large portion of the population remained resident, with a maximum time to recapture of nine years. The effect of logging history (unlogged vs 16-30 years post-logging regrowth) on apparent survival was minor and species specific, with no detectable effect for two species, a positive effect for one and negative for the other. There was no effect of logging history on abundance or body condition for any of these species. Apparent survival of residents was not strongly influenced by weather variation (except for the smallest species), unlike previous studies outside of refugia. Despite annual variation in abundance and body condition across the 14 years of the study, no relationship with extreme weather was evident. The location of our study area in a climate refuge potentially buffered bat population dynamics from extreme weather. These results support the value of climate refugia in mitigating climate change impacts, though the lack of an external control highlights the need for further studies on the functioning of climate refugia. Relatively stable population dynamics were not compromised by

  6. 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.

  7. 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.

  8. 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.

  9. Effect of Load Duration on Timber Structures in Denmark

    DEFF Research Database (Denmark)

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

    2003-01-01

    . The parameters in these models are fitted by the Maximum Likelihood Method using data relevant for Danish structural timber and the statistical uncertainty is quantified. The reliability is evaluated using representative shortand long-term limit states, and the load duration factor kmod is estimated using......Load duration effects 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, Barret & Foschi's model and Foschi & Yao's model...

  10. 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...

  11. 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

  12. 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 ...

  13. 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 ...

  14. 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...

  15. 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....

  16. 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...

  17. 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

  18. 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.

  19. Managing for timber and biodiversity in the Congo Basin

    DEFF Research Database (Denmark)

    Nasi, Robert; Billand, Alain; van Vliet, Nathalie

    2012-01-01

    concessions) and analyze the existing issues and options for managing actively both timber and biodiversity with a special emphasis on wildlife and the role of certification. A few promising but yet ‘unfinished’ examples do exist in the region and we review these cases to draw lessons and recommendations. We...... contend however that true multiple-use could only be realized by expanding beyond boundaries of formal management units through new innovative land-use units, allowing a spatial cohabitation of the interests of local people, of conservation proponents and of extractive industries in the same management...

  20. 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...

  1. 76 FR 1504 - Pipeline Safety: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure...

    Science.gov (United States)

    2011-01-10

    ... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No... Mitigation AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA); DOT. ACTION: Notice... system. To that end, the Hazardous Liquid and Gas Transmission Pipeline Integrity Management (IM...

  2. 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.

  3. A Numerical Analysis of the Resistance and Stiffness of the Timber and Concrete Composite Beam

    Directory of Open Access Journals (Sweden)

    Szumigała Ewa

    2015-03-01

    Full Text Available 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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

  14. 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

  15. 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.

  16. 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,...

  17. 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...

  18. 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...

  19. 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...

  20. 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....

  1. 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.

  2. 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...

  3. 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....

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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.

  9. 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...

  10. 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

  11. 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...

  12. 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...

  13. 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

  14. 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...

  15. 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.

  16. Forest bat population dynamics over 14 years at a climate refuge: Effects of timber harvesting and weather extremes.

    Directory of Open Access Journals (Sweden)

    Bradley S Law

    Full Text Available Long-term data are needed to explore the interaction of weather extremes with habitat alteration; in particular, can 'refugia' buffer population dynamics against climate change and are they robust to disturbances such as timber harvesting. Because forest bats are good indicators of ecosystem health, we used 14 years (1999-2012 of mark-recapture data from a suite of small tree-hollow roosting bats to estimate survival, abundance and body condition in harvested and unharvested forest and over extreme El Niño and La Niña weather events in southeastern Australia. Trapping was replicated within an experimental forest, located in a climate refuge, with different timber harvesting treatments. We trapped foraging bats and banded 3043 with a 32% retrap rate. Mark-recapture analyses allowed for dependence of survival on time, species, sex, logging treatment and for transients. A large portion of the population remained resident, with a maximum time to recapture of nine years. The effect of logging history (unlogged vs 16-30 years post-logging regrowth on apparent survival was minor and species specific, with no detectable effect for two species, a positive effect for one and negative for the other. There was no effect of logging history on abundance or body condition for any of these species. Apparent survival of residents was not strongly influenced by weather variation (except for the smallest species, unlike previous studies outside of refugia. Despite annual variation in abundance and body condition across the 14 years of the study, no relationship with extreme weather was evident. The location of our study area in a climate refuge potentially buffered bat population dynamics from extreme weather. These results support the value of climate refugia in mitigating climate change impacts, though the lack of an external control highlights the need for further studies on the functioning of climate refugia. Relatively stable population dynamics were not

  17. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  18. 26 CFR 1.611-1 - Allowance of deduction for depletion.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Allowance of deduction for depletion. 1.611-1... depletion. (a) Depletion of mines, oil and gas wells, other natural deposits, and timber—(1) In general... mines, oil and gas wells, other natural deposits, and timber, a reasonable allowance for depletion. In...

  19. 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...

  20. 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...

  1. 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....

  2. 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)

  3. 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...

  4. 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...

  5. 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.

  6. 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....

  7. 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)

  8. 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...

  9. 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...

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  15. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  16. PROFIT-PC: a program for estimating maximum net revenue from multiproduct harvests in Appalachian hardwoods

    Science.gov (United States)

    Chris B. LeDoux; John E. Baumgras; R. Bryan Selbe

    1989-01-01

    PROFIT-PC is a menu driven, interactive PC (personal computer) program that estimates optimum product mix and maximum net harvesting revenue based on projected product yields and stump-to-mill timber harvesting costs. Required inputs include the number of trees/acre by species and 2 inches diameter at breast-height class, delivered product prices by species and product...

  17. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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

  4. 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 ...

  5. 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...

  6. 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...

  7. 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...

  8. 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 ...

  9. 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...

  10. 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.

  11. 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...

  12. 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...

  13. 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 ...

  14. 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...

  15. 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

  16. 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

  17. 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...

  18. 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

  19. 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....

  20. 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,...

  1. 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...

  2. 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)

  3. 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.

  4. 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.

  5. 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...

  6. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  7. Radiation situation and irradiation level in forest workers in places of timber works in alienation zone of Chernobyl Atomic Power Plant

    International Nuclear Information System (INIS)

    Kalashnikova, Z.V.; Karachov, Yi.Yi.; Berezhna, T.Yi.; Kuchma, M.D.

    1997-01-01

    The radiation hygienic situation in the forest plots and dose load of the personnel at timber works in the alienation zone of the Chernobyl Atomic Power Plant was evaluated.It has been revealed that the density of contamination of the forest soil at the areas of timber works was 155.4-447.3 kBq centre dot m 2 . Maximum year equivalent dose on the lungs and total dose of external and internal irradiation in the forest workers in the zone of alienation during the work at the areas were about 40% of the values of the respective dose limits for the population of B category

  8. 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

  9. Trading sulfur dioxide allowances

    International Nuclear Information System (INIS)

    Goldburg, C.B.; Lave, L.B.

    1992-01-01

    The 1990 Clean Air Act is aimed at generators larger than 25 MW, as these are the largest polluters. Market incentives give each source an emissions allocation but also flexibility. If a plant has lower emissions than the target, it can sell the 'surplus' emissions as allowances to plants that fail to meet the target. Only a few trades have occurred to date. Market-based incentives should lower the costs of improving environmental quality significantly. However, currently institutional dificulties hamper implementation

  10. 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...

  11. 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....

  12. 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...

  13. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  14. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  15. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  16. 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.

  17. 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 ...

  18. 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...

  19. Minimizing corrosive action in timber bridges treated with waterborne preservatives

    Science.gov (United States)

    Samuel L. Zelinka; Douglas R. Rammer; James P. Wacker

    2007-01-01

    This work will briefly review published literature and current research activities on the corrosion of metals in contact with wood treated with waterborne alternatives to CCA. In addition, recommendations to minimize these corrosive effects in timber bridges will be discussed.

  20. 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.

  1. 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...

  2. 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...

  3. 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 ...

  4. 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.

  5. 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...

  6. 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...

  7. 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...

  8. 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....

  9. 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 ...

  10. 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.

  11. 42 CFR 50.504 - Allowable cost of drugs.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Allowable cost of drugs. 50.504 Section 50.504... APPLICABILITY Maximum Allowable Cost for Drugs § 50.504 Allowable cost of drugs. (a) The maximum amount which may be expended from program funds for the acquisition of any drug shall be the lowest of (1) The...

  12. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  13. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  14. Timbered masonry for earthquake resistance in Europe

    Directory of Open Access Journals (Sweden)

    Dutu, A.

    2012-12-01

    Full Text Available 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 structural system is basically the same: the wooden structural system bears mainly the horizontal loads while the masonry supports the gravity loads. The study includes a brief report on the seismicity of each country where this traditional type of building made of timbered framed masonry is found, together with the description of these buildings’ constructive systems.

    Europa es un continente que está sujeto a una significativa actividad sísmica. Por esta razón, se debe analizar el comportamiento sísmico, no sólo de las nuevas estructuras, diseñadas sobre la base de códigos más exigentes, sino también de los diversos tipos de estructuras antiguas. En este artículo se analizan las estructuras constituidas por mampostería y madera, que se pueden encontrar en Portugal, Turquía, Francia, Inglaterra, Grecia, Rumania, Italia, España, Alemania y Escandinavia. Aunque estas estructuras presentan diferencias en cuanto a detalles constructivos, su sistema estructural es idéntico: el sistema estructural de madera absorbe principalmente las cargas horizontales, mientras que la mampostería garantiza la resistencia a la acción de la gravedad. El estudio presentado incluye un breve informe acerca de la sismicidad de los países en que existe el tipo de construcción mencionado, conjuntamente con la descripción de los sistemas constructivos específicos de cada país.

  15. 40 CFR 35.2025 - Allowance and advance of allowance.

    Science.gov (United States)

    2010-07-01

    ... advance of allowance. (a) Allowance. Step 2+3 and Step 3 grant agreements will include an allowance for facilities planning and design of the project and Step 7 agreements will include an allowance for facility... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Allowance and advance of allowance. 35...

  16. Dynamics of Timber Market Integration in Sweden

    Directory of Open Access Journals (Sweden)

    Vishal Chandr Jaunky

    2015-12-01

    Full Text Available This paper addresses the performance of the timber markets (Scots pine, Pinus silvestris L. and Norway spruce, Picea abies (L. Karst. by evaluating the order of market integration in three Swedish regions (Central, Northern, and Southern. Quarterly data of delivery prices are employed over the period 1999Q1–2012Q4. Various unit root and cointegration tests have been computed. The results indicate that the variables are integrated of first order and co-integrated, especially after controlling for structural breaks. This supports the law-of-one-price hypothesis (LOP. However, the effects of structural shocks on forestry are arguably significant and these are controlled for while performing a vector error-correction mechanism (VECM-based Granger-causality test. Bi-directional causality between the Northern and central markets is uncovered in the short-run. In the long-run, a similar causal effect is detected between Northern and Southern markets while the central market emerges as the price leader. Further investigation is carried out using variance decompositions and impulse response functions and these approaches also tend to confirm the existence of a single market well, as price interdependence between markets.

  17. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  18. Carga máxima de fósforo admissível ao reservatório Piraquara II, uma aplicação do processo TMDL Maximum allowable phosphorus load in the Piraquara II reservoir, a TMDL process application

    Directory of Open Access Journals (Sweden)

    Simone Bittencourt

    2006-06-01

    Full Text Available Para implementação e operacionalização da política brasileira de recursos hídricos, é imprescindível o uso de ferramentas de planejamento que considerem o efeito de todas as atividades ou processos que causam ou contribuem para a degradação da qualidade de um corpo d'água. Neste sentido, aplicou-se o processo TMDL (total maximum daily load, desenvolvido pela Agência de Proteção Ambiental dos Estados Unidos (EPA, para o P, na área de drenagem de contribuição ao futuro reservatório Piraquara II, bacia hidrográfica do rio Piraquara, Paraná. O processo TMDL determina a quantidade máxima de cargas de um poluente que um corpo d'água pode receber sem violar os padrões estabelecidos de qualidade da água e aloca cargas deste poluente entre fontes de poluição pontuais e difusas. No presente estudo, utilizou-se o método TMDL, com o objetivo de demonstrar ser ele uma ferramenta útil no processo de gestão dos recursos hídricos. Simularam-se cenários de uso do solo, por meio de modelagem matemática, até obter-se uma concentração de P total no reservatório abaixo da faixa limite para ocorrência de eutrofização, de 0,025 a 0,10 mg L-1, estabelecida no estudo. Realizou-se uma simulação de uso atual do solo, visando prever a condição inicial de qualidade da água no corpo d'água, na qual a concentração de P total no reservatório resultante não atendeu ao padrão estabelecido. Procedeu-se a uma segunda simulação com adoção das medidas de controle, recomposição de mata ciliar e plantio direto, para reduzir a exportação de carga de P total da bacia. Obteve-se uma melhoria na qualidade da água do reservatório, indicando que as medidas adotadas foram suficientes para atingir o padrão estabelecido, o que demonstra a aplicabilidade do método.For the implementation and operation of the Brazilian Federal law on water resources of 1997 it is indispensable to use planning tools that take into account the effect of

  19. 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.)

  20. 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.

  1. 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...

  2. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  3. Experiment on Behavior of a New Connector Used in Bamboo (Timber Frame Structure under Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Junwen Zhou

    2018-01-01

    Full Text Available Connection is an important part of the bamboo and timber structure, and it directly influences the overall structural performance and safety. Based on a comprehensive analysis of the mechanical performance of several wood connections, a new connector for the bamboo (timber frame joint was proposed in this paper. Three full-scale T-type joint specimens were designed to study the mechanical performance under cyclic loading. The thickness of the hollow steel column was different among three specimens. The specimens were loaded under displacement control with a rate of 10 mm per minute until the specimens reach failure. It was observed that the failures of three specimens were caused by the buckling of flanges in the compression and that the steel of connections does not yield. The load-displacement hysteretic curve for three specimens is relatively plump, and the stiffness of connection degenerates with the increasing of cyclic load. The maximum rotation is 0.049 rad, and the energy dissipation coefficient is 1.77. The thickness of the hollow steel column of the connector has significant impact on the energy dissipation capacity and the strength of the connection. A simplified moment-rotation hysteresis model for the joint was proposed.

  4. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  5. 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 ...

  6. Maximum power per VA control of vector controlled interior ...

    Indian Academy of Sciences (India)

    Thakur Sumeet Singh

    2018-04-11

    Apr 11, 2018 ... Department of Electrical Engineering, Indian Institute of Technology Delhi, New ... The MPVA operation allows maximum-utilization of the drive-system. ... Permanent magnet motor; unity power factor; maximum VA utilization; ...

  7. 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...

  8. 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...

  9. 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....

  10. 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.

  11. 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...

  12. 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...

  13. 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....

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  19. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  20. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  1. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  2. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  3. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  4. 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....

  5. 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...

  6. 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.

  7. 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...

  8. 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.

  9. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  10. Effect of fire-induced damage on the uniaxial strength characteristics of solid timber: A numerical study

    International Nuclear Information System (INIS)

    Hopkin, D J; El-Rimawi, J; Lennon, T; Silberschmidt, V V

    2011-01-01

    The advent of the structural Eurocodes has allowed civil engineers to be more creative in the design of structures exposed to fire. Rather than rely upon regulatory guidance and prescriptive methods engineers are now able to use such codes to design buildings on the basis of credible design fires rather than accepted unrealistic standard-fire time-temperature curves. Through this process safer and more efficient structural designs are achievable. The key development in enabling performance-based fire design is the emergence of validated numerical models capable of predicting the mechanical response of a whole building or sub-assemblies at elevated temperature. In such a way, efficiency savings have been achieved in the design of steel, concrete and composite structures. However, at present, due to a combination of limited fundamental research and restrictions in the UK National Annex to the timber Eurocode, the design of fire-exposed timber structures using numerical modelling techniques is not generally undertaken. The 'fire design' of timber structures is covered in Eurocode 5 part 1.2 (EN 1995-1-2). In this code there is an advanced calculation annex (Annex B) intended to facilitate the implementation of numerical models in the design of fire-exposed timber structures. The properties contained in the code can, at present, only be applied to standard-fire exposure conditions. This is due to existing limitations related to the available thermal properties which are only valid for standard fire exposure. In an attempt to overcome this barrier the authors have proposed a 'modified conductivity model' (MCM) for determining the temperature of timber structural elements during the heating phase of non-standard fires. This is briefly outlined in this paper. In addition, in a further study, the MCM has been implemented in a coupled thermo-mechanical analysis of uniaxially loaded timber elements exposed to non-standard fires. The finite element package DIANA was adopted

  11. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  12. In vitro propagation of an endangered medicinal timber species ...

    African Journals Online (AJOL)

    The over exploitation of African mahogany in tropical forest has threatened the genetic base of this useful timber and medicinal tree species and as such, an experiment was conducted on the in vitro culture of Khaya grandifoliola, an endangered tree species commonly found in the high forest zones of West Africa to explore ...

  13. 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...

  14. 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...

  15. An Ethnobotanical Survey on Fuel Wood and Timber plant Species ...

    African Journals Online (AJOL)

    Yomi

    2011-12-19

    Dec 19, 2011 ... 3Department of Botany, Post Graduate College Abbottabad, Pakistan. Accepted 17 March, 2011. A survey was conducted to explore the fuel wood species and timber producing species of Kaghan valleys, Pakistan. Consumption pattern and impact on the forest resources were also taken into consideration.

  16. 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

  17. 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...

  18. 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...

  19. 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....

  20. 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.

  1. Chapter 4: Lateral design of cross-laminated timber buildings

    Science.gov (United States)

    John W. van de Lindt; Douglas Rammer; Marjan Popovski; Phil Line; Shiling Pei; Steven E. Pryor

    2013-01-01

    Cross-laminated timber (CLT) is an innovative wood product that was developed approximately two decades ago in Europe and has since been gaining in popularity. Based on the experience of European researchers and designers, it is believed that CLT can provide the U.S. market the opportunity to build mid- and high-rise wood buildings. This Chapter presents a summary of...

  2. 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.

  3. 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...

  4. 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.

  5. Smart timber bridge on geosynthetic reinforced soil (GRS) abutments

    Science.gov (United States)

    Adam Senalik; James P. Wacker; Travis K. Hosteng; John Hermanson

    2017-01-01

    Recently, Buchanan County, Iowa, has cooperated with the U.S. Federal Highway Administration (FHWA), USDA Forest Service, Forest Products Laboratory (FPL), and Iowa State University’s Bridge Engineering Center (ISU–BEC) to initiate a project involving the construction and monitoring of a glued-laminated (glulam) timber superstructure on geosynthetic reinforced soil (...

  6. 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...

  7. TRIM timber projections: an evaluation based on forest inventory measurements.

    Science.gov (United States)

    John R. Mills

    1989-01-01

    Two consecutive timberland inventories collected from permanent plots in the natural pine type in North Carolina were used to evaluate the timber resource inventory model (TRIM). This study compares model predictions with field measurements and examines the effect of inventory data aggregation on the accuracy of projections. Projections were repeated for two geographic...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. an assessment of timber trees producing valuable fruits and seeds ...

    African Journals Online (AJOL)

    User

    It is observed that most of the timber trees producing valuable fruits and seeds have low ... sector of the economy by providing major raw materials (saw logs, ... the trees also produce industrial raw materials like latex, ... villagers while avoiding some of the ecological costs of ..... enzymes of rats with carbon tetrachloride.

  13. 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 ...

  14. probabilistic evaluation of eur robabilistic evaluation of eur a timber

    African Journals Online (AJOL)

    eobe

    than steel or concrete [13]. Fire is an emotive sub ... Kaura1, I. Abubakar2, U. Hassan3 and I. Aliyu4 ... portal frame in fire is the failure of the rafter-column connection that re column ...... Thin-webbed Timber Beams”, Asian Journal of Civil.

  15. 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...

  16. 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

  17. Supply and demand of timber for wood turning in Maine

    Science.gov (United States)

    Eric H. Wharton; Robert L., Jr. Nevel; Douglas S. Powell; Douglas S. Powell

    1987-01-01

    An analytical report on the volume of wood used by the wood-turning industry in Maine, and the volume of timber from the state's timberlands that may be suitable for turnstock. Findings are based on the third forest resource survey of Maine timberlands, and an industry canvass of primary manufacturing mills using wood from Maine timberlands, both conducted in 1982...

  18. Chapter 5: Connections Connections in cross-laminated timber buildings

    Science.gov (United States)

    Mohammad Mohammad; Bradford Douglas; Douglas Rammer; Steven E. Pryor

    2013-01-01

    The light weight of cross-laminated timber (CLT) products combined with the high level of prefabrication involved, in addition to the need to provide wood-based alternative products and systems to steel land concrete, have significantly contributed to the development of CLT products and systems, especially in mid-rise buildings (5 to 9 stories). While this product is...

  19. 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...

  20. 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.

  1. 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...

  2. 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...

  3. 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,...

  4. 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.

  5. Effects of timber harvest following wildfire in western North America

    Science.gov (United States)

    David L. Peterson; James K. Agee; Gregory H. Aplet; Dennis P. Dykstra; Russell T. Graham; John F. Lehmkuhl; David S. Pilliod; Donald F. Potts; Robert F. Powers; John D. Stuart

    2009-01-01

    Timber harvest following wildfire leads to different outcomes depending on the biophysical setting of the forest, pattern of burn severity, operational aspects of tree removal, and other management activities. Fire effects range from relatively minor, in which fire burns through the understory and may kill a few trees, to severe, in which fire kills most trees and...

  6. A Computer Program to Evaluate Timber Production Investments Under Uncertainty

    Science.gov (United States)

    Dennis L. Schweitzer

    1968-01-01

    A computer program has been written in Fortran IV to calculate probability distributions of present worths of investments in timber production. Inputs can include both point and probabilistic estimates of future costs, prices, and yields. Distributions of rates of return can also be constructed.

  7. Strength and stiffness capacity utilisation of timber members in roof ...

    African Journals Online (AJOL)

    C Brand Wessels, Nils-Olaf Petersen. Abstract. The main objective of this study was to determine which property, of the six strength and stiffness properties used in structural timber design, was the most influential in the design of nail-plated roof trusses. Thirty recently completed nail-plated roof truss designs were randomly ...

  8. The Four Corners timber harvest and forest products industry, 2012

    Science.gov (United States)

    Colin B. Sorenson; Steven W. Hayes; Todd A. Morgan; Eric A. Simmons; Micah G. Scudder; Chelsea P. McIver; Mike T. Thompson

    2016-01-01

    This report traces the flow of timber harvested in the "Four Corners" States (Arizona, Colorado, New Mexico, and Utah) during calendar year 2012, describes the composition and operations of the region’s primary forest products industry, and quantifies volumes and uses of wood fiber. Recent changes in the wood products industry are discussed, as well as trends...

  9. The Four Corners timber harvest and forest products industry, 2007

    Science.gov (United States)

    Steven W. Hayes; Todd A. Morgan; Erik C. Berg; Jean M. Daniels; Mike Thompson

    2012-01-01

    This report traces the flow of timber harvested in the "Four Corners" States (Arizona, Colorado, New Mexico, and Utah) during calendar year 2007, describes the composition and operations of the region's primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as...

  10. 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 ...

  11. 25 CFR 163.23 - Advance payment for timber products.

    Science.gov (United States)

    2010-04-01

    ... contracts. However, no advance payment will be required that would make the sum of such payment and of... required, advance payments will operate the same as provided for in § 163.23(a) of this part. ... 25 Indians 1 2010-04-01 2010-04-01 false Advance payment for timber products. 163.23 Section 163...

  12. Contribution of timber exports to economic growth in Nigeria: an ...

    African Journals Online (AJOL)

    The paper examined the contribution of timber exports to the economic growth in Nigeria, using an econometric approach. Augmented Dickey-Fuller (ADF) and Johansen Co-integration techniques were respectively used to test for unit root and examine the relationship between the variables used. In addition, Granger ...

  13. 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.

  14. How to establish, maintain and use timber depletion accounts

    Science.gov (United States)

    William C. Siegel

    2001-01-01

    Section 1221 of the Internal Revenue Code defines capital expenditures. In general, these are amounts spent to acquire real estate or equipment, or to make improvements that increase the value of real estate or equipment already owned. Forestry examples include land, buildings, standing timber, reforestation costs, and tractors and trucks. Property owners who incur...

  15. Timber resource statistics for the Sacramento resource area of California.

    Science.gov (United States)

    Karen L. Waddell; Patricia M. Bassett

    1997-01-01

    This report is a summary of timber resource statistics for the Sacramento Resource Area of California, which includes Butte, Colusa, El Dorado, Glenn, Lake, Napa, Nevada, Placer, Plumas, Sacramento, Sierra, Sutter, Tehama, Yolo, and Yuba Counties. Data were collected as part of a statewide multiresource inventory. The inventory sampled private and public lands except...

  16. 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.

  17. 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...

  18. Harvest choice and timber supply models for forest forecasting

    Science.gov (United States)

    Maksym Polyakov; David N Wear

    2010-01-01

    Timber supply has traditionally been modeled using aggregate data, whereas individual harvest choices have been shown to be sensitive to the vintage and condition of forest capital stocks. In this article, we build aggregate supply models for four roundwood products in a seven-state region of the US South directly from stand-level harvest choice models applied to...

  19. Building aggregate timber supply models from individual harvest choice

    Science.gov (United States)

    Maksym Polyakov; David N. Wear; Robert Huggett

    2009-01-01

    Timber supply has traditionally been modelled using aggregate data. In this paper, we build aggregate supply models for four roundwood products for the US state of North Carolina from a stand-level harvest choice model applied to detailed forest inventory. The simulated elasticities of pulpwood supply are much lower than reported by previous studies. Cross price...

  20. Forest management planning for timber production: a sequential approach

    Science.gov (United States)

    Krishna P. Rustagi

    1978-01-01

    Explicit forest management planning for timber production beyond the first few years at any time necessitates use of information which can best be described as suspect. The two-step approach outlined here concentrates on the planning strategy over the next few years without losing sight of the long-run productivity. Frequent updating of the long-range and short-range...

  1. An Ethnobotanical Survey on Fuel Wood and Timber plant Species ...

    African Journals Online (AJOL)

    A survey was conducted to explore the fuel wood species and timber producing species of Kaghan valleys, Pakistan. Consumption pattern and impact on the forest resources were also taken into consideration. A questionnaire was used as a survey instrument to obtain desired data. For this study, 10 villages were randomly ...

  2. 49 CFR 192.328 - Additional construction requirements for steel pipe using alternative maximum allowable operating...

    Science.gov (United States)

    2010-10-01

    ... Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS... of this root cause analysis must be reported to each PHMSA pipeline safety regional office where the...

  3. 77 FR 75699 - Pipeline Safety: Reporting of Exceedances of Maximum Allowable Operating Pressure

    Science.gov (United States)

    2012-12-21

    ... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No... AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA); DOT. ACTION: Notice; Issuance of... occurs. This reporting requirement is applicable to all gas transmission pipeline facility owners and...

  4. 77 FR 56555 - Approval and Promulgation of Implementation Plans; State of Missouri; Maximum Allowable Emission...

    Science.gov (United States)

    2012-09-13

    ... of facilities affected by this rule include but are not limited to utility and industrial boilers... other gases with low hydrogen sulfide and/or mercury content, as discussed in greater detail below. EPA... hydrogen sulfide levels less than or equal to four parts-per-million by volume as measured by American...

  5. 49 CFR 192.620 - Alternative maximum allowable operating pressure for certain steel pipelines.

    Science.gov (United States)

    2010-10-01

    ... (SCADA) system, other leak detection system, or an alternative method of control. (iii) Remote valve... outs, leakage, or other activities or conditions affecting the safety operation of the pipeline. (ii... requirements of § 192.707(d) except in agricultural areas, large water crossings or swamp, steep terrain, or...

  6. 49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

    Science.gov (United States)

    2010-10-01

    ... (incorporated by reference, see § 192.7); or (ii) American Society of Mechanical Engineers (ASME) B31.8.... Certification must address material properties such as chemistry, minimum yield strength and minimum wall...

  7. Assessing the Suitability of Future Multi- and Hyperspectral Satellite Systems for Mapping the Spatial Distribution of Norway Spruce Timber Volume

    Directory of Open Access Journals (Sweden)

    Sascha Nink

    2015-09-01

    Full Text Available The availability of accurate and timely information on timber volume is important for supporting operational forest management. One option is to combine statistical concepts (e.g., small area estimates with specifically designed terrestrial sampling strategies to provide estimations also on the level of administrative units such as forest districts. This may suffice for economic assessments, but still fails to provide spatially explicit information on the distribution of timber volume within these management units. This type of information, however, is needed for decision-makers to design and implement appropriate management operations. The German federal state of Rhineland-Palatinate is currently implementing an object-oriented database that will also allow the direct integration of Earth observation data products. This work analyzes the suitability of forthcoming multi- and hyperspectral satellite imaging systems for producing local distribution maps for timber volume of Norway spruce, one of the most economically important tree species. In combination with site-specific inventory data, fully processed hyperspectral data sets (HyMap were used to simulate datasets of the forthcoming EnMAP and Sentinel-2 systems to establish adequate models for estimating timber volume maps. The analysis included PLS regression and the k-NN method. Root Mean Square Errors between 21.6% and 26.5% were obtained, where k-NN performed slightly better than PLSR. It was concluded that the datasets of both simulated sensor systems fulfill accuracy requirements to support local forest management operations and could be used in synergy. Sentinel-2 can provide meaningful volume distribution maps in higher geometric resolution, while EnMAP, due to its hyperspectral coverage, can contribute complementary information, e.g., on biophysical conditions.

  8. 7 CFR 3565.210 - Maximum interest rate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Maximum interest rate. 3565.210 Section 3565.210... AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.210 Maximum interest rate. The interest rate for a guaranteed loan must not exceed the maximum allowable rate specified by the Agency in...

  9. 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

  10. The effect of fissures on the strength of structural timber

    Directory of Open Access Journals (Sweden)

    Íñiguez, Guillermo

    2010-06-01

    Full Text Available Detailed measurements of drying fissures were carried out on 28 pieces of gross cross-section structural Scots pine timber. Different parameters have been proposed to measure their magnitude: length, depth, thickness and slope of grain, as well as an index of area in the neutral axis plane (ratio of effective to total surface. The parameters of fissures have been related to bending strength, shear strength, modulus of elasticity and rupture energy obtained from mechanical tests, considering whether rupture is due to bending or shear. All of the fissures observed allows to classify the pieces as MEG according to the UNE 56544 standard. To quantify the magnitude of fissures the index of areas is proposed, while mechanical properties can be quantified by rupture energy. Analysis of the results does not show any relation between the fissures analyzed and the mode of failure, their magnitude and mechanical properties..

    Se han realizado mediciones detalladas de las fendas de secado en 28 piezas de madera de pino silvestre de gran escuadría. Se han propuesto diferentes parámetros para medir su magnitud en longitud, profundidad, grosor e inclinación, así como un índice de áreas en el plano medio de rasante (superficie eficaz respecto a superficie total. Se han relacionado los parámetros de fendas con resistencia a flexión, resistencia a cortante, módulo de elasticidad y energía de rotura obtenidos mediante ensayos mecánicos, teniendo en cuenta si la rotura se produce por flexión o por cortante. Todas las fendas observadas permiten clasificar las piezas como MEG según la norma UNE 56544. Se propone cuantificar las fendas mediante el índice de áreas y las propiedades mecánicas mediante la energía de rotura. El análisis realizado no muestra una relación significativa entre las fendas analizadas, los modos de rotura o las propiedades mecánicas.

  11. 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.

  12. Maximum penetration level of distributed generation without violating voltage limits

    NARCIS (Netherlands)

    Morren, J.; Haan, de S.W.H.

    2009-01-01

    Connection of Distributed Generation (DG) units to a distribution network will result in a local voltage increase. As there will be a maximum on the allowable voltage increase, this will limit the maximum allowable penetration level of DG. By reactive power compensation (by the DG unit itself) a

  13. Maximum entropy and Bayesian methods

    International Nuclear Information System (INIS)

    Smith, C.R.; Erickson, G.J.; Neudorfer, P.O.

    1992-01-01

    Bayesian probability theory and Maximum Entropy methods are at the core of a new view of scientific inference. These 'new' ideas, along with the revolution in computational methods afforded by modern computers allow astronomers, electrical engineers, image processors of any type, NMR chemists and physicists, and anyone at all who has to deal with incomplete and noisy data, to take advantage of methods that, in the past, have been applied only in some areas of theoretical physics. The title workshops have been the focus of a group of researchers from many different fields, and this diversity is evident in this book. There are tutorial and theoretical papers, and applications in a very wide variety of fields. Almost any instance of dealing with incomplete and noisy data can be usefully treated by these methods, and many areas of theoretical research are being enhanced by the thoughtful application of Bayes' theorem. Contributions contained in this volume present a state-of-the-art overview that will be influential and useful for many years to come

  14. 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.

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. An investigation and understanding of the mechanical response of Palmyrah timber

    International Nuclear Information System (INIS)

    Sobier, Hatim; Menzemer, C.C.; Srivatsan, T.S.

    2003-01-01

    The Palmyrah tree flourishes in tropical areas around South East Asia, and particularly in Sri Lanka. Palmyrah is an important economic resource for the region, and has found use in structural applications for both residential dwellings and commercial buildings. While there is a great deal of local field experience with Palmyrah, the mechanical properties have not been well characterized or understood. In an effort to assist engineers with the design and efficient use of the timber, a study was undertaken to evaluate the mechanical response of Palmyrah and develop estimates of design allowable properties. Properties evaluated include static bending strength, modulus, compression parallel and perpendicular to the grain, shear parallel to the grain and tensile strength parallel and perpendicular to the grain. In order to gain insight into the behavior of the wood, samples were examined using standard optical microscopy techniques. In addition, available fracture surfaces were examined using scanning electron microscopy

  20. Timber productivity research gaps for extensive forest management

    Science.gov (United States)

    L.C. Irland

    2011-01-01

    On extensive areas of small scale forests, significant opportunities for improving the value of future timber harvests while also improving other resource values are now being missed. A new focus on practical extensive management research is needed, especially as implementation of intensive practices has been declining in many areas, and new ‘‘close to nature’’...

  1. 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...

  2. Long-term Deformation Measurements of Atypical Roof Timber Structures

    Directory of Open Access Journals (Sweden)

    Jiří Bureš

    2014-06-01

    Full Text Available The paper includes conclusions from evaluation of results obtained from long-termmeasuring of innovative atypical roof timber structures. Based on the results ofmeasurements of vertical and horizontal deformation components it is possible to analyzethe real behavior of structures in given conditions. By assessing deformations in variousstages, including particularly external and internal environment temperatures, relative airhumidity and moisture content of wood, decisive parameters for real structure behaviorcan be established. The data are processed from period 2001 – 2013.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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 ...

  9. 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....

  10. 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...

  11. 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.

  12. 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...

  13. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  14. 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...

  15. Maximum entropy principal for transportation

    International Nuclear Information System (INIS)

    Bilich, F.; Da Silva, R.

    2008-01-01

    In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.

  16. 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.

  17. a Historical Timber Frame Model for Diagnosis and Documentation Before Building Restoration

    Science.gov (United States)

    Koehl, M.; Viale, A.; Reeb, S.

    2013-09-01

    The aim of the project that is described in this paper was to define a four-level timber frame survey mode of a historical building: the so-called "Andlau's Seigniory", Alsace, France. This historical building (domain) was built in the late XVIth century and is now in a stage of renovation in order to become a heritage interpretation centre. The used measurement methods combine Total Station measurements, Photogrammetry and 3D Terrestrial Laser scanner. Different modelling workflows were tested and compared according to the data acquisition method, but also according to the characteristics of the reconstructed model in terms of accuracy and level of detail. 3D geometric modelling of the entire structure was performed including modelling the degree of detail adapted to the needs. The described 3D timber framework exists now in different versions, from a theoretical and geometrical one up to a very detailed one, in which measurements and evaluation of deformation by time are potentially allowed. The virtually generated models involving archaeologists, architects, historians and specialists in historical crafts, are intended to be used during the four stages of the project: (i) knowledge of the current state of needs for diagnosis and understanding of former construction techniques; (ii) preparation and evaluation of restoration steps; (iii) knowledge and documentation concerning the archaeological object; (iv) transmission and dissemination of knowledge through the implementation of museum animations. Among the generated models we can also find a documentation of the site in the form of virtual tours created from panoramic photographs before and during the restoration works. Finally, the timber framework model was structured and integrated into a 3D GIS, where the association of descriptive and complementary digital documents was possible. Both offer tools leading to the diagnosis, the understanding of the structure, knowledge dissemination, documentation and the

  18. 76 FR 70883 - Clothing Allowance

    Science.gov (United States)

    2011-11-16

    ... prescription skin cream for the ``face, neck, hands, arms, or any area not covered by clothing may come into... the clothing or outergarment due to a second appliance or medication.'' This language will clarify that a second clothing allowance may be paid when a second appliance and/or medication increases the...

  19. 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...

  20. 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....

  1. Surfaces allowing for fractional statistics

    International Nuclear Information System (INIS)

    Aneziris, Charilaos.

    1992-07-01

    In this paper we give a necessary condition in order for a geometrical surface to allow for Abelian fractional statistics. In particular, we show that such statistics is possible only for two-dimentional oriented surfaces of genus zero, namely the sphere S 2 , the plane R 2 and the cylindrical surface R 1 *S 1 , and in general the connected sum of n planes R 2 -R 2 -R 2 -...-R 2 . (Author)

  2. 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...

  3. 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...

  4. 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;...

  5. 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...

  6. 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...

  7. 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...

  8. 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.

  9. 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...

  10. 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.

  11. 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...

  12. 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,...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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

  5. 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...

  6. 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)

  7. 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

  8. 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...

  9. 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...

  10. 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

  11. 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...

  12. 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

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. 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...

  19. 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.

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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.

  6. 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

  7. FIRE PROTECTION OF TIMBER STRUCTURES STRENGTHENED WITH FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Radek Zigler

    2015-12-01

    Full Text Available Modern, progressive methods of structures’ strengthening based on the use of composite materials composed of high strength fibers (carbon, glass, aramid or basalt and matrices based on epoxy resins brings, among many indisputable advantages (low weight, high effectiveness, easy application etc. also some disadvantages. One of the major disadvantages is a low fire resistance of these materials due to the low glass transition temperature Tg of the resin used. Based on an extensive research of strengthening of historic structures with FRP materials [1], the article outlines possible approaches to this problem, especially while strengthening timber load- bearing structures of historic buildings.

  8. On the Architectural Qualities of Cross Laminated Timber

    DEFF Research Database (Denmark)

    Bejder, Anne Kirkegaard; Kirkegaard, Poul Henning; Fisker, Anna Marie

    2010-01-01

    In resent years wood as a building material has gain renewed focus and with that new production methods and wooden products have been developed. One of these products is Cross Laminated Timber (CLT) which, by means of high-technology production and a distinctive construction with layers of lamellae...... glued together crosswise, possesses structural capacities which are out of woods nature. Several research studies have clarified that CLT has many qualities within the engineering field but knowledge regarding its applications and aesthetics is more insufficient. Thus, the purpose of this paper...

  9. Solar water heating and its prospect for timber drying application

    Energy Technology Data Exchange (ETDEWEB)

    Yin, B T

    1982-01-01

    The technical requirements for timber drying are discussed, and the possibility of using a solar water heating system to substitute for conventional fuel in a modern kiln is looked into from heat transfer considerations. At the moment, conventional fuel is used to generate steam for the heating of air in a kiln. If hot water is to be substitued for steam as the heating medium, the heating coil size required is larger. This size is determined relative to that of a steam coil for similar kiln operating temperatures. 5 references.

  10. Mechanical properties of timber from wind damaged Norway spruce

    DEFF Research Database (Denmark)

    Hoffmeyer, Preben

    2003-01-01

    A storm may subject a tree to such bending stresses that extensive compression damage develops in the lee side. The tree may survive the wind load or it may be thrown. However, the damage is inherent and it may be of a magnitude to influence the mechanical properties of boards sawn from the stem....... The paper reports on a investigation of the relation between degree of damage and mechanical proper-ties of sawn timber from wind damaged Norway spruce. The project included about 250 bolts from wind damaged trees. The majority of bolts were cut to deliver a full-diameter plank containing the pith...

  11. 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...

  12. 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. ...

  13. 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...

  14. 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....

  15. Minimal length, Friedmann equations and maximum density

    Energy Technology Data Exchange (ETDEWEB)

    Awad, Adel [Center for Theoretical Physics, British University of Egypt,Sherouk City 11837, P.O. Box 43 (Egypt); Department of Physics, Faculty of Science, Ain Shams University,Cairo, 11566 (Egypt); Ali, Ahmed Farag [Centre for Fundamental Physics, Zewail City of Science and Technology,Sheikh Zayed, 12588, Giza (Egypt); Department of Physics, Faculty of Science, Benha University,Benha, 13518 (Egypt)

    2014-06-16

    Inspired by Jacobson’s thermodynamic approach, Cai et al. have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar-Cai derivation http://dx.doi.org/10.1103/PhysRevD.75.084003 of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure p(ρ,a) leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature k. As an example we study the evolution of the equation of state p=ωρ through its phase-space diagram to show the existence of a maximum energy which is reachable in a finite time.

  16. Emission allowances stall in marketplace

    International Nuclear Information System (INIS)

    Malec, W.F.

    1993-01-01

    Misinformation and public misunderstanding have given emissions trading a bad reputation in the public marketplace, says William F. Malec, executive vice president of the Tennessee Valley Authority (TVA), in Knoxville, Tennessee. Media coverage of a May 1992 emissions-allowance trade between TVA and Wisconsin Power and Light open-quotes focused on the agreement's pollution-trading aspects, not its overall potential economic and environmental benefits,close quotes Malec says. Such negative portrayal of TVA's transaction sparked severe public criticism and charges that emissions trading gives utilities the right to pollute. open-quotes The fact is that TVA sought the emissions-trading agreement as a means to reduce overall emissions in the most cost-effective way,close quotes Malec explains. Emissions trading allows a company with emission levels lower than clean-air standards to earn open-quotes credits.close quotes These credits then may be purchased by a company with emission levels that exceed federal standards. Under this arrangement, the environment is protected and companies that buy credits save money because they do not have to purchase expensive emissions-control devices or reduce their production levels. Malec says TVA decided to enter into the emissions-allowance market, not only to cut costs, but also to publicize the existence and benefits of emissions trading. However, TVA's experience proves that open-quotes people will not accept what they do not understand,close quotes concludes Malec, open-quotes especially when complex environmental issues are involved.close quotes

  17. Pareto versus lognormal: a maximum entropy test.

    Science.gov (United States)

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano

    2011-08-01

    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  18. Cross-laminated timber made of Hungarian raw materials

    Science.gov (United States)

    Marko, G.; Bejo, L.; Takats, P.

    2016-04-01

    Cross-laminated timber (CLT), generally made out of softwood, enjoys increasing popularity throughout Europe. This material offers a versatile, eco-friendly technology to create strong, lightweight and energy-efficient buildings. Unfortunately, the sites and climatic conditions in Hungary are not suitable for growing high-quality coniferous trees. Transporting raw materials from other countries (sometimes thousands of kilometres away) negates the environmental advantages of wood-based construction. Local options are definitely preferable from an ecological aspect. Poplar wood (populus spp.) is of great economic importance in Hungary. There are several relatively high density, high strength varieties growing in large quantities in Hungary, that may be used as alternatives to softwood, with comparable properties. There is an increasing interest in using poplar as a construction material, especially in regions were there is a shortage of traditional construction timber. This paper presents the results of a preliminary investigation to create CLT using poplar lumber. Laboratory-scale CLT specimens were created in a hot press, and tested for their loadbearing capacity. The MOR values of poplar CLT are comparable to, albeit somewhat lowerthan those of softwood CLT. Further investigations are required to establish the economic viability and technological conditions for the commercial production of poplar CLT.

  19. A review on environmental education in Myanmar Timber Enterprise

    International Nuclear Information System (INIS)

    Khin-Zaw

    2001-08-01

    Environmental education in the Myanmar Timber Enterprise (MTE) began formally in 1996. Environmental considerations had been incorporated in the deparmental instructions and operation manuals of extraction and wood processing since the emergence of MTE, then named STate Timber Board in 1948, but the modern concept of environmental conservation for sustainable development was introduced to the staff of MTE beginning only in 1996. The training contents constitute the defintion of environmental conservation as sustainable development, global environmental awareness, Myanmar's participation in global environmental undertakings, national institution and awareness progammes, the concept of reduced impact logging, code of harvesting, and above all, the environmental impact assessment (EIA) methodology as a tool for environmental management. In the MTE, 20 officers have been trained at a two-week workshop on EIA; 180 trainees from the Extraction Department, mostly the persons in charge of extraction ranges, have been trained at five-day short and mobile trainings on EIA around the country; and 948 officers and subordinate staff have been trained at the vocational training centres of MTE covering the above outline of the course, depending upon the training duration and trainees' rank, up to the end of December, 2000. Evaluation on EIA workshop and some training courses, problems and constraints encountered at the trainings and suggestions sought are also discussed in the paper. (author)

  20. 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)

  1. Noise, Worker Perception, and Worker Concentration in Timber Harvesting Activity

    Directory of Open Access Journals (Sweden)

    Efi Yuliati Yovi

    2012-01-01

    Full Text Available Timber harvesting activities are unquestionably related with high risk of work accidents and health disorders.Such activities were not only burdened the workers with heavy physical workloads due to uneasy workingenvironment, and massive work materials and tools, but also physiopsychologically burdened workers as theywere imposed with both mechanical and acoustic vibrations (noise produced by the chainsaw. However,  it is acommon practice that most of the workers still ignored the importance of the use of noise reduction devices suchas earmuff or ear plug.  This study was aimed to reveal the factual effects of noise on work concentration of theworkers to provide a scientific basis in supporting efforts in improving workers’ attitude.  The results confirmedthat chainsaw might produce noise during operation.  Noise intensities received by both right and left ears werenot significantly different, indicating that left-handed and normal workers received similar degree of noise inboth side of ears. Further, results also showed that there was a significant difference on the perception and workconcentration of chainsaw operators versus sedentary people to the noise.  These findings proved that hearingability of chainsaw operators had declined due to frequent noise exposure.Keywords: timber harvesting, physio-psychological disorder, noise, chainsaw

  2. 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

  3. Maximum support resistance with steel arch backfilling

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    A system of backfilling for roadway arch supports to replace timber and debris lagging is described. Produced in West Germany, it is known as the Bullflex system and consists of 23 cm diameter woven textile tubing which is inflated with a pumpable hydraulically-setting filler of the type normally used in mines. The tube is placed between the back of the support units and the rock face and creates an early-stage interlocking effect.

  4. Multi-Channel Maximum Likelihood Pitch Estimation

    DEFF Research Database (Denmark)

    Christensen, Mads Græsbøll

    2012-01-01

    In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristics....... This essentially means that the model allows for different conditions in the various channels, like different signal-to-noise ratios, microphone characteristics and reverberation. Moreover, the method does not assume that a certain array structure is used but rather relies on a more general model and is hence...

  5. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  6. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  7. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  8. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

  9. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  10. 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.

  11. Timbered Architecture in the Regions of the Walddeutsche Settlements

    Science.gov (United States)

    Hrehorowicz – Gaber, Hanna

    2017-10-01

    The centuries-old Polish history, its complicated fortunes and borders changing over the centuries have caused the cultural heritage to be a reflection of the fate of the inhabitants, the intermingling of ethnic groups and the common formation of the culture of the region. The cultural area of southern Poland is particularly full of layers, where diverse historical and geographical influences blend together. That is why the presence of the common construction type for the wooden objects on the two ends of southern Poland, in two different geographical realms, is such an interesting testimony of the Polish cultural melting pot. The main area of the occurrence of the timbered architecture is the borderland of Germany, the Czech Republic and Poland. This type of houses was built for the first time in the Middle Ages in the area of Upper Lusatia, then this type of housing has spread to northern Czech Republic and the western part of Lower Silesia. In Poland, there are two main clusters of the occurrence of timbered structures: in Lower Silesia and in the Subcarpathian province, where this type of buildings has been rooted with the German settlers, called the Walddeutsche in this area. The colonisation was also accompanied by the model of settlement village systems moved from the west, the development of the plot, and this specific type of construction. The architecture of the Jasielsko-Sanockie Valleys and the Dynowskie foothills is an interesting, though a very poor form in relation to the Sudeten houses, as the architecture non-recurring in other Polish regions has been formed as a result of the intermingling of the cultures. In this area, the houses and farm buildings with the timbered structures were used most often by farmers and they were not too impressive, so that the residents did not notice their uniqueness. Today, in the natural landscape, they disappear one by one, as a result of lack of maintenance and the replacement of the old materials with objects of a

  12. 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...

  13. 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....

  14. 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....

  15. 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.

  16. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  17. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  18. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  19. LCLS Maximum Credible Beam Power

    International Nuclear Information System (INIS)

    Clendenin, J.

    2005-01-01

    The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

  20. Quality of Pinus elliottii sawn timber from tapped forests

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Gonzalez de Cademartori

    2012-12-01

    Full Text Available This study aimed to characterize the quality of Pinus elliottii sawn timber extracted from tapped forests and processed in a sawmill in São José do Norte (RS. Four butt logs and four upper logs for each of the three existing diameter grades were selected and sawed. The wood pieces were analyzed after sawing and after kiln drying. The presence of knots, which occurred due to the absence of forest management and influenced the qualitative classification of the wood pieces, was observed mainly in the samples from upper logs. The process of resin tapping contributed to a higher incidence of resin pockets in the samples from butt logs, also influencing the qualitative classification of the samples. The appearance of drying defects did not modify the classification of the wood samples from butt and upper logs.

  1. Creep Properties of Walikukun (Schouthenia ovata Timber Beams

    Directory of Open Access Journals (Sweden)

    Ali Awaludin

    2016-09-01

    Full Text Available This study presents an evaluation of creep constants of Walikukun (Schoutheniaovata timber beams when rheological model of four solid elements, which is obtained byassembling Kelvin and Maxwell bodies in parallel configuration, was adopted. Creep behaviorobtained by this method was further discussed and compared with creep behavior developedusing phenomenological model of the previous study. Creep data of previous study was deformationmeasurement of Walikukun beams having cross-section of 15 mm by 20 mm with a clearspan of 550 mm loaded for three weeks period under two different room conditions: with andwithout Air Conditioner. Creep behavior given by both four solid elements model and phenomenological(in this case are power functions had good agreement during the period of creepmeasurement, but they give different prediction of creep factor beyond this period. The powerfunction of phenomenological model could give a reasonable creep prediction, while for the foursolid elements model a necessary modification is required to adjust its long-term creep behavior.

  2. Sertifikat Lestari PT. Diamond Raya Timber: Aset atau Beban?

    Directory of Open Access Journals (Sweden)

    Ahmad Maryudi

    2007-01-01

    Several environmental non-government organizations and green parties pursue various strategies to promote sustainable management of forest resource. Due to the increasing environment awareness of some segments of timber users, they have established a certification body and developed a set of criteria and indicators, against which the performance of participating forest companies will be assessed. Early experiences in Indonesia showed that certification received warm welcome from several forest companies, as there is no question that they saw the attraction of being certified. However, it appears that their enthusiasm was dampened by the experience of a certified company. Certification might have been seen as more of a liability than an asset as the economic benefits from market access became less clear, while the costs became more apparent. The use of rigid standards might result in “negative” responses from forest companies. More proactive approaches might encourage the companies to join certification.

  3. Market chain analysis of candeia timber (Eremanthus erythropappus

    Directory of Open Access Journals (Sweden)

    José Fábio Camolesi

    2009-09-01

    Full Text Available This study characterized and analysed the market chain of candeia timber intended for oil production, and estimatedthe marketing margin retained by each chain participant. The study site encompassed two regions of Minas Gerais state whosedistinctive mark is great abundance of native candeia forest (Eremanthus erythropappus. Data were collected through interviewswith rural workers, candeia woodland owners and manufacturers of candeia oil and alpha-bisabolol. The marketing margin wascomputed as the percentage retained by each chain participant on each kilo of alpha-bisabolol sold. It was concluded that alphabisabololdistributors are the participants reaping the greatest marketing margin, and also that rural producers should sell candeiatimber directly to oil manufacturers, with no middlemen wholesalers, in order to boost their marketing margin.

  4. Treatment of timber products with gaseous borate esters, Part 1: factors influencing the treatment process

    CSIR Research Space (South Africa)

    Turner, P

    1995-08-01

    Full Text Available Several factors which influence the treatment of timber products with vapour phase preservatives such as borate esters are considered. Gas flow rate through the substrate was found to be a significant factor limiting both preservative penetration...

  5. Physiology and silviculture of black walnut for combined timber and nut production

    Science.gov (United States)

    J. W. Van Sambeek; George Rink

    1981-01-01

    Research literature was reviewed for evidence supporting the management of black walnut plantations for combined timber and nut production. The silviculture of the species is discussed in relation to dual cropping. Stimulation and phenology of flowering and fruiting are reviewed.

  6. Draft Genome Sequence of Clostridium mangenotii TR, Isolated from the Fecal Material of a Timber Rattlesnake

    Science.gov (United States)

    Cochran, Philip A.; Dowd, Scot E.; Andersen, Kylie; Anderson, Nichole; Brennan, Rachel; Brook, Nicole; Callaway, Tracie; Diamante, Kimberly; Duberstine, Annie; Fitch, Karla; Freiheit, Heidi; Godlewski, Chantel; Gorman, Kelly; Haubrich, Mark; Hernandez, Mercedes; Hirtreiter, Amber; Ivanoski, Beth; Jaminet, Xochitl; Kirkpatrick, Travis; Kratowicz, Jennifer; Latus, Casey; Leable, Tiegen; Lingafelt, Nicole; Lowe, DeAnna; Lowrance, Holly; Malsack, Latiffa; Mazurkiewicz, Julie; Merlos, Persida; Messley, Jamie; Montemurro, Dawn; Nakitare, Samora; Nelson, Christine; Nye, Amber; Pazera, Valerie; Pierangeli, Gina; Rellora, Ashley; Reyes, Angelica; Roberts, Jennifer; Robins, Shadara; Robinson, Jeshannah; Schultz, Alissa; Seifert, Sara; Sigler, Elona; Spangler, Julie; Swift, Ebony; TenCate, Rebecca; Thurber, Jessica; Vallee, Kristin; Wamboldt, Jennifer; Whitten, Shannon; Woods, De’andrea; Wright, Amanda; Yankunas, Darin

    2014-01-01

    Here, we report the draft genome sequence of Clostridium mangenotii strain TR, which was isolated from the fecal material of a timber rattlesnake. This bacterium is nonpathogenic but contains 68 genes involved in virulence, disease, and defense. PMID:24407632

  7. 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...

  8. 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.

  9. ECOLOGY OF CICONIIFORMES BIRDS IN FORESTS OF CRIMEA TIMBER ENTERPRISE OF KRASNODAR TERRITORY

    Directory of Open Access Journals (Sweden)

    A. A. GOJKO

    2010-01-01

    Full Text Available Features of ecology ciconiiformes birds in the conditions of plantings of the Crimean timber enterprise of Krasnodar territory are considered. Biotopes, number, phenology, nested ecology and feed of birds are analyzed.

  10. Stages of growth theory and money flows from commercial banks in timber-dependent communities.

    Science.gov (United States)

    Con H. Schallau

    1980-01-01

    The flow of funds from commercial banks in western Oregon may indicate how a timber shortfall will affect community stability. Results suggest the inappropriateness of a single public forest management policy.

  11. 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...

  12. 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...

  13. 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...

  14. 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

  15. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  16. 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.

  17. 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....

  18. 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)

  19. 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...

  20. 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...

  1. 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...

  2. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  3. Non-destructive evaluation of timber structures in a historical building of Tiradentes , MG

    Directory of Open Access Journals (Sweden)

    Luciana Barbosa de Abreu

    2013-09-01

    Full Text Available Problems related to the durability of wood are commonly found in historical buildings structures. Preservation and conservation resolutions must be adopted, in order to avoid losses and substitutions, which mischaracterize buildings. Non-destructive methods for detecting deterioration should be used in order to substantiate decisions and increase the longevity of historical heritage. This work was carried out in order to perform non-destructive essays to infer about the integrity of a beam and a pillar of the original construction of the Sobrado Ramalho, a historical building of the city of Tiradentes, MG. The equipments utilized were the Stress Wave Timer and resistograph. Samples of the elements were taken for analysis of density. The results showed that, in both structures, to calculate the dynamic modulus of elasticity, there was no significant difference for the application of stress wave timer on the alignments studied. There was no significant difference between the directions of application of the resistograph on the pillar, due to its apparent entirety and regular sessions, practically square, and to not being loaded eccentrically. In the case of the beam, there was significant difference, presumably because it has cracks in its traction line. The equipments, unknown by professionals of heritage conservation allow promising methodologies for inspection of timber structures in service.

  4. Metabolic chemotypes of CITES protected Dalbergia timbers from Africa, Madagascar, and Asia.

    Science.gov (United States)

    McClure, Pamela J; Chavarria, Gabriela D; Espinoza, Edgard

    2015-05-15

    The genus Dalbergia includes approximately 250 species worldwide. Of these, 58 species are of economic importance and listed under CITES. Identification of illegal transnational timber trade is a challenge because logs or boards lack the typical descriptors used for species identification such as leaves and flowers; therefore, frequently the lowest taxonomic determination of these tree byproducts is genus. In this study, we explore the use of Direct Analysis in Real Time (DART) Time-Of-Flight Mass Spectrometry (TOFMS) in making species determinations of protected Dalbergia trees from Africa, Madagascar, and Asia. Metabolic profiles were collected using DART TOFMS from the heartwood of seven species and the sapwood of 17 species of Dalbergia. Also included in this study are 85 Dalbergia heartwood samples from Madagascar that were only identified to genus. In all, 21 species comprising 235 specimens were analyzed, the metabolic chemotypes were interpreted, and the spectra were analyzed using chemometric tools. Dalbergia cochinchinensis and Dalbergia spp. from Madagascar (both CITES Appendix II) could be differentiated from each other and from the non-protected Dalbergia latifolia and Dalbergia melanoxylon. DART TOFMS is a valuable high-throughput tool useful for making phytochemical classifications of Dalbergia spp. The data produced allows the protected Dalbergias from Madagascar to be distinguished and can differentiate closely related rosewood trees. Published in 2015. This article is a U.S. Government work and is in the public domain in the USA.

  5. 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.

  6. Flight Dynamics and Abundance of Ips sexdentatus (Coleoptera: Curculionidae: Scolytinae in Different Sawmills from Northern Spain: Differences between Local Pinus radiata (Pinales: Pinaceae and Southern France Incoming P. pinaster Timber

    Directory of Open Access Journals (Sweden)

    Sergio López

    2012-01-01

    Full Text Available In January 2009, the windstorm “Klaus” struck the southern part of France, affecting 37.9 million m3 of maritime pine Pinus pinaster Aiton (Pinales: Pinaceae. This breeding plant material favored the outbreak of Ips sexdentatus (Börner (Coleoptera: Curculionidae: Scolytinae. As much of this timber is imported to the Basque Country (northern Spain, a potential risk to conifer stands is generated, due to the emergence of the incoming beetles. Thus, flight dynamics and beetle abundance were compared in different sawmills, according to the timber species (either local P. radiata D. Don or imported P. pinaster. A maximum flight peak of I. sexdentatus was observed in mid-June in P. pinaster importing sawmills, whereas a second lighter peak occurred in September. In contrast, only a maximum peak in mid-June was observed in P. radiata inhabiting beetles, being significantly smaller than in local P. pinaster trading sawmills. In addition, significant differences were found between imported P. pinaster and P. radiata regarding the number of insects beneath the bark. The development of IPM strategies for controlling I. sexdentatus populations is recommended, due to the insect abundance found in P. pinaster imported timber.

  7. 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.

  8. 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

  9. 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.

  10. Maximum organic carbon limits at different melter feed rates (U)

    International Nuclear Information System (INIS)

    Choi, A.S.

    1995-01-01

    This report documents the results of a study to assess the impact of varying melter feed rates on the maximum total organic carbon (TOC) limits allowable in the DWPF melter feed. Topics discussed include: carbon content; feed rate; feed composition; melter vapor space temperature; combustion and dilution air; off-gas surges; earlier work on maximum TOC; overview of models; and the results of the work completed

  11. System for memorizing maximum values

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1992-08-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either linear or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  12. Remarks on the maximum luminosity

    Science.gov (United States)

    Cardoso, Vitor; Ikeda, Taishi; Moore, Christopher J.; Yoo, Chul-Moon

    2018-04-01

    The quest for fundamental limitations on physical processes is old and venerable. Here, we investigate the maximum possible power, or luminosity, that any event can produce. We show, via full nonlinear simulations of Einstein's equations, that there exist initial conditions which give rise to arbitrarily large luminosities. However, the requirement that there is no past horizon in the spacetime seems to limit the luminosity to below the Planck value, LP=c5/G . Numerical relativity simulations of critical collapse yield the largest luminosities observed to date, ≈ 0.2 LP . We also present an analytic solution to the Einstein equations which seems to give an unboundedly large luminosity; this will guide future numerical efforts to investigate super-Planckian luminosities.

  13. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  14. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  15. 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....

  16. 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

  17. Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

    Science.gov (United States)

    Hall, Alex; Taylor, Andy

    2017-06-01

    We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

  18. Assessing allowable take of migratory birds

    Science.gov (United States)

    Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

    2009-01-01

    Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was < 3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be < rmax. Further, the ratio of desired harvest rate to 0.5 x rmax may be a useful metric for ascertaining the applicability of specific requirements of the National Environmental Protection Act.

  19. 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,...

  20. Projections of the U.S. timber supply and demand situation to 2050 : draft findings from the USDA Forest Service 2000 RPA Timber Assessment.

    Science.gov (United States)

    Richard Haynes; Darius Adams; Ralph Alig; David Brooks; Irene Durbak; James Howard; Peter Ince; David McKeever; John Mills; Ken Skog; Xiaoping. Zhou

    2001-01-01

    The Draft RPA Timber Assessment projects, over the next 50 years, the likelihood of increasing abundance of softwoods in the South and decreasing abundance of hardwoods in the South. These trends in supply, along with projected contributions from the North and West, imply U.S. consumption needs could be met without increasing net product imports and would not increase...

  1. CONTEMPORARY CONSTRUCTIONS OF TIMBER PASSIVE HOUSES IN SLOVENIA

    Directory of Open Access Journals (Sweden)

    Manja Kitek Kuzman

    2013-12-01

    Full Text Available Energy efficiency is essential in the efforts to achieve a 20% reduction of primary power consumption by 2020. It is widely recognized that the potential of energy saving in buildings is large. Considering the tendencies of energy production and price, it is becoming urgent to reduce energy consumption in buildings. The choice of materials for a building with a high energy efficiency becomes much more important and strategies for reducing the use of primary energy for the production of materials and components becomes key. Renewable building materials should already be integrated into the early phases of building planning. The positive trend towards wooden construction is dictated by international guidelines, where a wooden building is an important starting point, not only for low-energy, but also lowemission building with exceptional health and safety aspects. In Europe, the most comprehensive and widely used is a concept of ultralow energy house, more precisely, the passive house concept. Most Slovenian buildings combine contemporary styling with a degree of energy efficiency that comes close to passive house standards. It is widely recognized that the Slovenian construction industry is relatively advanced in the field of low energy buildings. In the light of the growing importance of energy-efficient building methods, it could be said that timber passive house would play an increasingly important role in the future.

  2. Global timber investments, wood costs, regulation, and risk

    International Nuclear Information System (INIS)

    Cubbage, Frederick; Koesbandana, Sadharga; Gonzalez, Ronalds; Carrero, Omar; MacIntyre, Charles; Abt, Robert; Phillips, Richard; Mac Donagh, Patricio; Rubilar, Rafael; Balmelli, Gustavo; Olmos, Virginia Morales; De La Torre, Rafael; Murara, Mauro; Hoeflich, Vitor Afonso; Kotze, Heynz; Frey, Gregory; Adams, Thomas; Turner, James; Lord, Roger; Huang, Jin; McGinley, Kathleen

    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 - Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay - were substantial. Eucalyptus species returns were generally greater than those for Pinus species in each country, with most having Internal Rates of Return (IRRs) of 20% per year or more, as did teak. Pinus species in South America were generally closer to 15%, except in Argentina, where they were 20%. IRRs were less, but still attractive for plantations of coniferous or deciduous species in China, South Africa, New Zealand, Indonesia, and the United States, ranging from 7% to 12%. Costs of wood production at the cost of capital of 8% per year were generally cheapest for countries with high rates of return and for pulpwood fiber production, which would favor vertically integrated firms in Latin America. But wood costs at stumpage market prices were much greater, making net wood costs for open market wood more similar among countries. In the Americas, Chile and Brazil had the most regulatory components of sustainable forest management, followed by Misiones, Argentina and Oregon in the U.S. New Zealand, the United States, and Chile had the best rankings regarding risk from political, commercial, war, or government actions and for the ease of doing business. Conversely, Venezuela, Indonesia, Colombia, and Argentina had high risk ratings, and Brazil, Indonesia, and Venezuela were ranked as more difficult countries for ease of business. (author)

  3. Global timber investments, wood costs, regulation, and risk

    Energy Technology Data Exchange (ETDEWEB)

    Cubbage, Frederick; Koesbandana, Sadharga; Gonzalez, Ronalds; Carrero, Omar; MacIntyre, Charles; Abt, Robert; Phillips, Richard [Forestry and Environmental Resources, North Carolina State University, Raleigh, NC (United States); Mac Donagh, Patricio [Universidad Nacional de Misiones (UNAM), Lisandro de la Torre s/n, CP 3380, Eldorado, Misiones (Argentina); Rubilar, Rafael [Universidad de Concepcion, Victoria 631, Casilla 160-C - Correo 3, Concepcion (Chile); Balmelli, Gustavo [Instituto Nacional de Investigacion Agropecuria, INIA Tacuarembo, Ruta 5, Km 386, Tacuarembo (Uruguay); Olmos, Virginia Morales [Weyerhaeuser Company, La Rosa 765, Melo (Uruguay); De La Torre, Rafael [CellFor, 247 Davis Street, Athens, GA (United States); Murara, Mauro [Universidade do Contestado, R. Joaquim Nabuco, 314 Bairro Cidade Nova, Porto Uniao, Santa Catarina (Brazil); Hoeflich, Vitor Afonso [Universidade Federal do Parana, Av. Pref. Lothario Meissner, 900, 80210-170, Jardim Botanico, Curitiba, Parana (Brazil); Kotze, Heynz [Komatiland Forests (Pty) Ltd, P.O. Box 14228, Nelspruit (South Africa); Frey, Gregory [World Bank, 1818 H. Street NW, Washington, DC (United States); Adams, Thomas; Turner, James [New Zealand Forest Research Institute Ltd., Scion, 49 Sala St., Rotorua (New Zealand); Lord, Roger [Mason, Bruce, and Girard, Inc., 707 SW Washington St., Portland, Oregon (United States); Huang, Jin [Abt Associates, 4550 Montgomery Avenue, Bethesda, MD (United States); McGinley, Kathleen [International Institute of Tropical Forestry, USDA Forest Service, c/o 920 Main Campus Dr. Suite 300, Raleigh, NC (United States)

    2010-12-15

    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 - Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay - were substantial. Eucalyptus species returns were generally greater than those for Pinus species in each country, with most having Internal Rates of Return (IRRs) of 20% per year or more, as did teak. Pinus species in South America were generally closer to 15%, except in Argentina, where they were 20%. IRRs were less, but still attractive for plantations of coniferous or deciduous species in China, South Africa, New Zealand, Indonesia, and the United States, ranging from 7% to 12%. Costs of wood production at the cost of capital of 8% per year were generally cheapest for countries with high rates of return and for pulpwood fiber production, which would favor vertically integrated firms in Latin America. But wood costs at stumpage market prices were much greater, making net wood costs for open market wood more similar among countries. In the Americas, Chile and Brazil had the most regulatory components of sustainable forest management, followed by Misiones, Argentina and Oregon in the U.S. New Zealand, the United States, and Chile had the best rankings regarding risk from political, commercial, war, or government actions and for the ease of doing business. Conversely, Venezuela, Indonesia, Colombia, and Argentina had high risk ratings, and Brazil, Indonesia, and Venezuela were ranked as more difficult countries for ease of business. (author)

  4. System identification of timber masonry walls using shaking table test

    Science.gov (United States)

    Roy, Timir B.; Guerreiro, Luis; Bagchi, Ashutosh

    2017-04-01

    Dynamic study is important in order to design, repair and rehabilitation of structures. It has played an important role in the behavior characterization of structures; such as: bridges, dams, high rise buildings etc. There had been substantial development in this area over the last few decades, especially in the field of dynamic identification techniques of structural systems. Frequency Domain Decomposition (FDD) and Time Domain Decomposition are most commonly used methods to identify modal parameters; such as: natural frequency, modal damping and mode shape. The focus of the present research is to study the dynamic characteristics of typical timber masonry walls commonly used in Portugal. For that purpose, a multi-storey structural prototype of such wall has been tested on a seismic shake table at the National Laboratory for Civil Engineering, Portugal (LNEC). Signal processing has been performed of the output response, which is collected from the shaking table experiment of the prototype using accelerometers. In the present work signal processing of the output response, based on the input response has been done in two ways: FDD and Stochastic Subspace Identification (SSI). In order to estimate the values of the modal parameters, algorithms for FDD are formulated and parametric functions for the SSI are computed. Finally, estimated values from both the methods are compared to measure the accuracy of both the techniques.

  5. Roads, interrupted dispersal, and genetic diversity in timber rattlesnakes.

    Science.gov (United States)

    Clark, Rulon W; Brown, William S; Stechert, Randy; Zamudio, Kelly R

    2010-08-01

    Anthropogenic habitat modification often creates barriers to animal movement, transforming formerly contiguous habitat into a patchwork of habitat islands with low connectivity. Roadways are a feature of most landscapes that can act as barriers or filters to migration among local populations. Even small and recently constructed roads can have a significant impact on population genetic structure of some species, but not others. We developed a research approach that combines fine-scale molecular genetics with behavioral and ecological data to understand the impacts of roads on population structure and connectivity. We used microsatellite markers to characterize genetic variation within and among populations of timber rattlesnakes (Crotalus horridus) occupying communal hibernacula (dens) in regions bisected by roadways. We examined the impact of roads on seasonal migration, genetic diversity, and gene flow among populations. Snakes in hibernacula isolated by roads had significantly lower genetic diversity and higher genetic differentiation than snakes in hibernacula in contiguous habitat. Genetic-assignment analyses revealed that interruption to seasonal migration was the mechanism underlying these patterns. Our results underscore the sizeable impact of roads on this species, despite their relatively recent construction at our study sites (7 to 10 generations of rattlesnakes), the utility of population genetics for studies of road ecology, and the need for mitigating effects of roads.

  6. 46 CFR 154.440 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-522). (b) A greater allowable stress than required in paragraph (a)(1) of this section may be...

  7. 46 CFR 154.421 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and Classing...

  8. 34 CFR 304.21 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Allowable costs. 304.21 Section 304.21 Education... Grantee § 304.21 Allowable costs. In addition to the allowable costs established in the Education... allowable expenditures by projects funded under the program: (a) Cost of attendance, as defined in Title IV...

  9. 2 CFR 215.27 - Allowable costs.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Allowable costs. 215.27 Section 215.27... § 215.27 Allowable costs. For each kind of recipient, there is a set of Federal principles for determining allowable costs. Allowability of costs shall be determined in accordance with the cost principles...

  10. 50 CFR 80.15 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Allowable costs. 80.15 Section 80.15... WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS § 80.15 Allowable costs. (a) What are allowable costs? Allowable costs are costs that are necessary and reasonable for accomplishment of approved...

  11. 49 CFR 266.11 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Allowable costs. 266.11 Section 266.11... TRANSPORTATION ACT § 266.11 Allowable costs. Allowable costs include only the following costs which are properly allocable to the work performed: Planning and program operation costs which are allowed under Federal...

  12. Last Glacial Maximum Salinity Reconstruction

    Science.gov (United States)

    Homola, K.; Spivack, A. J.

    2016-12-01

    It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

  13. Maximum Parsimony on Phylogenetic networks

    Science.gov (United States)

    2012-01-01

    Background Phylogenetic networks are generalizations of phylogenetic trees, that are used to model evolutionary events in various contexts. Several different methods and criteria have been introduced for reconstructing phylogenetic trees. Maximum Parsimony is a character-based approach that infers a phylogenetic tree by minimizing the total number of evolutionary steps required to explain a given set of data assigned on the leaves. Exact solutions for optimizing parsimony scores on phylogenetic trees have been introduced in the past. Results In this paper, we define the parsimony score on networks as the sum of the substitution costs along all the edges of the network; and show that certain well-known algorithms that calculate the optimum parsimony score on trees, such as Sankoff and Fitch algorithms extend naturally for networks, barring conflicting assignments at the reticulate vertices. We provide heuristics for finding the optimum parsimony scores on networks. Our algorithms can be applied for any cost matrix that may contain unequal substitution costs of transforming between different characters along different edges of the network. We analyzed this for experimental data on 10 leaves or fewer with at most 2 reticulations and found that for almost all networks, the bounds returned by the heuristics matched with the exhaustively determined optimum parsimony scores. Conclusion The parsimony score we define here does not directly reflect the cost of the best tree in the network that displays the evolution of the character. However, when searching for the most parsimonious network that describes a collection of characters, it becomes necessary to add additional cost considerations to prefer simpler structures, such as trees over networks. The parsimony score on a network that we describe here takes into account the substitution costs along the additional edges incident on each reticulate vertex, in addition to the substitution costs along the other edges which are

  14. 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.

  15. Encroachment Dynamics of Juniperus virginiana L. and Mesic Hardwood Species into Cross Timbers Forests of North-Central Oklahoma, USA

    Directory of Open Access Journals (Sweden)

    Daniel L. Hoff

    2018-02-01

    Full Text Available Cross Timbers forests, typically dominated by Quercus stellata Wangenh. and Q. marilandica Muenchh., are the transition zone between eastern deciduous forest and prairie in the southern Great Plains. Fire exclusion beginning in the mid-1900s has led to increasing stand density and encroachment of fire-intolerant Juniperus virginiana L. and mesic hardwood. We measured current forest structure and tree ages of 25 stands (130 plots in north-central Oklahoma to characterize the extent and dynamics of encroachment. The respective basal area and stand density of the overstory (diameter at breast height; dbh > 10 cm were 19.0 m2 ha−1 and 407 trees ha−1 with Q. stellata comprising 43% of basal area and 42% of stand density. Quercus marilandica represented only 3% of basal area and 4% of overstory density. Juniperus virginiana represented 7% of basal area and 14% of stand density while mesic hardwoods, e.g., Celtis spp., Ulmus spp., Carya spp., 33% of basal area and stand density. The sapling layer was dominated by mesic hardwoods (68% and J. virginiana (25% while the seedling layer was dominated by mesic hardwoods (74%. The majority of Quercus recruited into the overstory between 1910–1970, while recruitment of J. virginiana and mesic hardwoods began more recently (post 1950s. Growth rate, based on the relationship between age and dbh, was faster for mesic hardwoods than for J. virginiana and Q. stellata. These results indicate that removal of recurrent surface fire as a disturbance agent has significantly altered forest composition in the Cross Timbers region by allowing encroachment of J. virginiana and fire-intolerant, mesic hardwoods. This increases wildfire risk because J. virginiana is very flammable and will alter how these forests respond to future drought and other disturbance events.

  16. Impacts of selective logging on inbreeding and gene flow in two Amazonian timber species with contrasting ecological and reproductive characteristics.

    Science.gov (United States)

    Vinson, C C; Kanashiro, M; Harris, S A; Boshier, D H

    2015-01-01

    Selective logging in Brazil allows for the removal of up to 90% of trees above 50 cm diameter of a given timber species, independent of a species' life history characteristics or how quickly it will recover. The genetic and demographic effects of selective logging on two Amazonian timber species (Dipteryx odorata Leguminosae, Jacaranda copaia Bignoniaceae) with contrasting ecological and reproductive characteristics were assessed in the same forest. Genetic diversity and gene flow were characterized by genotyping adults and seed sampled before and after logging, using hypervariable microsatellite markers. Overall, there were no short-term genetic impacts on the J. copaia population, with commercial application of current Brazilian forest management regulations. In contrast, for D. Odorata, selective logging showed a range of genetic impacts, with a 10% loss of alleles, and reductions in siring by pollen from trees within the 546-ha study area (23-11%) and in the number of pollen donors per progeny array (2.8-1.6), illustrating the importance of the surrounding landscape. Asynchrony in flowering between D. odorata trees led to trees with no breeding partners, which could limit the species reproduction and regeneration under current regulations. The results are summarized with other published studies from the same site and the implications for forest management discussed. The different types and levels of impacts associated with each species support the idea that ecological and genetic information by species, ecological guild or reproductive group is essential in helping to derive sustainable logging guidelines for tropical forests. © 2014 John Wiley & Sons Ltd.

  17. Maximum of difference assessment of typical semitrailers: a global study

    CSIR Research Space (South Africa)

    Kienhofer, F

    2016-11-01

    Full Text Available the maximum allowable width and frontal overhang as stipulated by legislation from Australia, the European Union, Canada, the United States and South Africa. The majority of the Australian, EU and Canadian semitrailer combinations and all of the South African...

  18. The constraint rule of the maximum entropy principle

    NARCIS (Netherlands)

    Uffink, J.

    1995-01-01

    The principle of maximum entropy is a method for assigning values to probability distributions on the basis of partial information. In usual formulations of this and related methods of inference one assumes that this partial information takes the form of a constraint on allowed probability

  19. Validation of the maximum allowable amounts of recycled binder, RAP, and RAS using accelerated pavement testing - interim report.

    Science.gov (United States)

    2014-05-01

    This report summarizes the work conducted on Project 0-6682 up to August 31, 2013. The report is : organized in five chapters corresponding to separate tasks in the project work plan, as follows: : Chapter 1 presents the summary of the findings f...

  20. Determination of the maximum-depth to potential field sources by a maximum structural index method

    Science.gov (United States)

    Fedi, M.; Florio, G.

    2013-01-01

    A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.