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

Science.gov (United States)

D.J. Brooks; R.W. Haynes

1994-01-01

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

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

Science.gov (United States)

John H. Beuter

1971-01-01

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

Timber management planning with timber ram and goal programming

Science.gov (United States)

Richard C. Field

1978-01-01

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

The 1993 RPA timber assessment update

Science.gov (United States)

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

1995-01-01

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

Global sustainable timber supply and demand

Science.gov (United States)

Peter J. Ince

2010-01-01

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

Traditional timber frames

NARCIS (Netherlands)

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

2014-01-01

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

Timber resources of southwest Oregon.

Science.gov (United States)

Patricia M. Bassett

1979-01-01

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

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.

Computer Vision for Timber Harvesting

DEFF Research Database (Denmark)

Dahl, Anders Lindbjerg

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

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

Directory of Open Access Journals (Sweden)

ND Ruwanpathirana

2014-06-01

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

Innovative Use and Characterization of Polymers for Timber-Related Construction

Directory of Open Access Journals (Sweden)

Mark Evernden

2010-02-01

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

Innovative Use and Characterization of Polymers for Timber-Related Construction

Science.gov (United States)

Darby, Antony; Ibell, Tim; Evernden, Mark

2010-01-01

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

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.

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...

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...

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

Science.gov (United States)

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

1987-01-01

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

The timber resources of Rhode Island

Science.gov (United States)

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

1957-01-01

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

Timber Curtain

DEFF Research Database (Denmark)

2015-01-01

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

Probabilistic modeling of timber structures

DEFF Research Database (Denmark)

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

2007-01-01

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

Timber in Bridge Structures

OpenAIRE

Detkin, Viktoria

2016-01-01

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

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

Science.gov (United States)

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

1998-01-01

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

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...

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.

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...

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 ...

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

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...

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

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.

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...

The 2005 RPA timber assessment update.

Science.gov (United States)

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

2007-01-01

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

1970 Oregon timber harvest.

Science.gov (United States)

Brian R. Wall

1971-01-01

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

Robustness Evaluation of Timber Structures

DEFF Research Database (Denmark)

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

2010-01-01

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

Inventory analysis of the timber industry in Ghana

NARCIS (Netherlands)

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

2010-01-01

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

Aesthetic Qualities of Cross Laminated Timber

DEFF Research Database (Denmark)

Bejder, Anne Kirkegaard

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

Reliability Analysis of Structural Timber Systems

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Hoffmeyer, P.

2000-01-01

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

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

Science.gov (United States)

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

2013-01-01

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

Control of borens in mine timbers

Energy Technology Data Exchange (ETDEWEB)

Yule, R A; Kennedy, M J

1978-07-01

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

General notes on ductility in timber structures

NARCIS (Netherlands)

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

2011-01-01

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

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

Directory of Open Access Journals (Sweden)

Elvida Yosefi Suryandari

2017-04-01

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

Probabilistic Modeling of Timber Structures

DEFF Research Database (Denmark)

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

2005-01-01

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

36 CFR 223.32 - Timber sale operating plan.

Science.gov (United States)

2010-07-01

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

Long term contracts signed in Slovak timber business

International Nuclear Information System (INIS)

Haluza, I.

2005-01-01

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

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

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...

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...

characterisation and grading of two selected timber species grown

African Journals Online (AJOL)

HOD

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

Timber resource statistics for eastern Washington, 1995.

Science.gov (United States)

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

1995-01-01

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

Timber floors strengthened with concrete

NARCIS (Netherlands)

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

1998-01-01

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

Timber-concrete composite floor systems

NARCIS (Netherlands)

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

1996-01-01

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

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

African Journals Online (AJOL)

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

Timber resource statistics for southwest Washington.

Science.gov (United States)

Patricia M. Bassett; Daniel D. Oswald

1981-01-01

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

Methodology for safety evaluation of existing timber elements

OpenAIRE

Sousa, Hélder S.

2013-01-01

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

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...

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....

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.

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.

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...

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...

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....

Reinforcement and recovery of timber structures

Directory of Open Access Journals (Sweden)

Antonio Alves Dias

2006-02-01

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

Value of timber continues to increase

International Nuclear Information System (INIS)

Haluza, I.

2007-01-01

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

Timber resource of Missouri's Prairie, 1972.

Science.gov (United States)

Jerold T. Hahn; Alexander Vasilevsky

1975-01-01

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

Timber Price Dynamics Following a Natural Catastrophe

OpenAIRE

Jeffrey P. Prestemon; Thomas P. Holmes

2000-01-01

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

Modified traditional Japanese timber joint system with retrofitting abilities

NARCIS (Netherlands)

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

2008-01-01

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

Timber resource statistics for western Washington.

Science.gov (United States)

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

1992-01-01

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

On several parameters of mechanized timbering for working faces

Energy Technology Data Exchange (ETDEWEB)

Klorik' yan, S Kh

1979-08-01

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

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

Markets, Government Policy, and China’s Timber Supply

Science.gov (United States)

Han Zhang; Joseph Buongiorno

2012-01-01

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

FRP reinforcement of timber structures

OpenAIRE

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

2015-01-01

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

36 CFR 223.62 - Timber purchaser road construction credit.

Science.gov (United States)

2010-07-01

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

Timber tracking

DEFF Research Database (Denmark)

Düdder, Boris; Ross, Omry

2017-01-01

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

Ranking independent timber investments by alternative investment criteria

Science.gov (United States)

Thomas J. Mills; Gary E. Dixon

1982-01-01

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

Aggregate Timber Supply: From the Forest to the Market

Science.gov (United States)

David N. Wear; Subhrendu K. Pattanayak

2003-01-01

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

Enviromentally Sound Timber Extracting Techniques for Small Tree Harvesting

Science.gov (United States)

Lihai Wang

1999-01-01

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

Collapse Analysis of Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2008-01-01

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

Section of mechanized timbering of an installation layer

Energy Technology Data Exchange (ETDEWEB)

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

1980-07-28

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

Timber Management Opportunities for Nebraska 1983-1992

Science.gov (United States)

W. Brad Smith; Tom D. Wardle

1984-01-01

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

Tall timber building technologies in The Netherlands

NARCIS (Netherlands)

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

2008-01-01

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

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.

Probabilistic Modelling of Timber Material Properties

DEFF Research Database (Denmark)

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

2001-01-01

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

Operability and location of Wisconsin's timber resource.

Science.gov (United States)

Jerold T. Hahn; Mark H. Hansen

1989-01-01

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

Operability and location of Michigan's timber resource.

Science.gov (United States)

Mark H. Hansen; Jerold T. Hahn

1987-01-01

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

Recommendations for sustainable development of non-timber forest products

Science.gov (United States)

Gina H. Mohammed

2001-01-01

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

Selection of Nepalese Timber for Small Wind Turbine Blade Construction

DEFF Research Database (Denmark)

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

2010-01-01

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

The Level of Utilization of Secondary Timber Species among Furniture Producers

Directory of Open Access Journals (Sweden)

Charles Antwi-Boasiako

2016-06-01

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

California’s forest products industry and timber harvest, 2006

Science.gov (United States)

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

2012-01-01

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

Case Studies on Timber Defects of Selected Traditional Houses in Malacca

Directory of Open Access Journals (Sweden)

Nor Haniza Ishak

2007-12-01

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

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

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.

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.

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....

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.

Industrialized timber structures.

Science.gov (United States)

1974-01-01

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

Timber resource statistics for the Olympic Peninsula, Washington.

Science.gov (United States)

Patricia M. Bassett; Daniel D. Oswald

1961-01-01

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

Procurement of timber for the Finnish forest industries

International Nuclear Information System (INIS)

Hakkila, P.

1995-01-01

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

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.

System Reliability of Timber Structures with Ductile Behaviour

DEFF Research Database (Denmark)

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

2011-01-01

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

Feasibility Investigation into Strengthening of Timber Bridge Stringers

Science.gov (United States)

2007-05-01

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

Timber price dynamics following a natural catastrophe

Science.gov (United States)

Jeffrey P. Prestemon; Thomas P. Holmes

2000-01-01

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

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

OpenAIRE

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

2011-01-01

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

Economic implications of manufacturing sawed ties and timbers

Science.gov (United States)

Lawrence D. Garrett; Lawrence D. Garrett

1969-01-01

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

Optimal control of raw timber production processes

Science.gov (United States)

Ivan Kolenka

1978-01-01

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

Effect of timber supplies on the efficiency of coal mining

Energy Technology Data Exchange (ETDEWEB)

Kulish, S A; Ponikarov, V D

1977-01-01

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

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.

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...

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

Tensile properties of machine strength graded timber for glued laminated timber

DEFF Research Database (Denmark)

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

1999-01-01

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

Finite element analysis of composite concrete-timber beams

Directory of Open Access Journals (Sweden)

N. C. S. FORTI

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

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...

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....

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...

Influence of steaming on drying quality and colour of beech timber

Directory of Open Access Journals (Sweden)

Milić Goran

2015-01-01

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

Alaska's timber harvest and forest products industry, 2005

Science.gov (United States)

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

2009-01-01

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

Robustness Analysis of Timber Truss Structure

DEFF Research Database (Denmark)

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

2010-01-01

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

Growing Timber Structures

DEFF Research Database (Denmark)

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

2013-01-01

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

Architectural and structural qualities in timber joints

DEFF Research Database (Denmark)

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

2016-01-01

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

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...

Comparative durability of timber bridges in the USA

Science.gov (United States)

James P. Wacker; Brian K. Brashaw

2017-01-01

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

Cattle and elk responses to intensive timber harvest.

Science.gov (United States)

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

2004-01-01

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

Whole tree transportation system for timber processing depots

Science.gov (United States)

John Lancaster; Tom Gallagher; Tim  McDonald; Dana Mitchell

2016-01-01

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

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

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

Robustness Analysis of a Timber Structure with Ductile Behaviour in Compression

DEFF Research Database (Denmark)

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

2011-01-01

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

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

Science.gov (United States)

Darius M. Adams; Richard W. Haynes

1996-01-01

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

Historic timber skeleton structures and the local seismic culture

Science.gov (United States)

Bostenaru, M.

2009-04-01

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

Supply Chain Planning for a Timber Harvesting Plus Sale Tender

Directory of Open Access Journals (Sweden)

Josef Holoubek

2015-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Mizyumskii, V A

1979-11-01

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

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...

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.

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.

Lateral testing of glued laminated timber tudor arch

Science.gov (United States)

Douglas R. Rammer; Philip Line

2016-01-01

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

Non-timber forest products and forest stewardship plans

Science.gov (United States)

Becky Barlow; Tanner Filyaw; Sarah W. Workman

2015-01-01

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

Infill Panels and the tube connection in timber frames

NARCIS (Netherlands)

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

2012-01-01

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

Lateral Stiffness of Timber Frames with CLT Infill Panels

NARCIS (Netherlands)

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

2011-01-01

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

Multi-Scalar Modelling for Free-form Timber Structures

DEFF Research Database (Denmark)

Poinet, Paul; Nicholas, Paul; Tamke, Martin

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Juan M. Pulhin

2016-07-01

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

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)

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

Richardson, Vanessa A; Peres, Carlos A

2016-01-01

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

Design of timber groynes

NARCIS (Netherlands)

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

2003-01-01

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

The Level of Utilization of Secondary Timber Species among Furniture Producers

OpenAIRE

Antwi-Boasiako, Charles; Boadu, Kwadwo Boakye

2016-01-01

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

Risks, Information and Short-Run Timber Supply

Directory of Open Access Journals (Sweden)

Francesca Rinaldi

2013-12-01

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

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

DEFF Research Database (Denmark)

Søndergaard, Asbjørn; Amir, Oded; Eversmann, Phillip

2016-01-01

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

Compression strength perpendicular to grain of structural timber and glulam

DEFF Research Database (Denmark)

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

1998-01-01

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

Seismic retrofitting of timber framed walls

Directory of Open Access Journals (Sweden)

Gonçalves, A. M.

2014-12-01

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

State forest timber sales in 2006

International Nuclear Information System (INIS)

Office National des Forets

2007-01-01

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

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

Science.gov (United States)

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

1993-01-01

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

Grip for sawing round timber

Energy Technology Data Exchange (ETDEWEB)

1982-07-01

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

Some background of monitoring and NDT also useful for timber structures

OpenAIRE

Kurz, Jochen Horst; Boller, Christian

2015-01-01

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

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

Directory of Open Access Journals (Sweden)

Meghan O’Brien

2017-12-01

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

Alaska’s timber harvest and forest products industry, 2011

Science.gov (United States)

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

2014-01-01

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

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.

Pre-Stressing Timber-Based Plate Tensegrity Structures

DEFF Research Database (Denmark)

Falk, Andreas; Kirkegaard, Poul Henning

2012-01-01

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

Statistical Analysis of Data for Timber Strengths

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2003-01-01

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

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

Science.gov (United States)

2010-07-01

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

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

DEFF Research Database (Denmark)

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

2010-01-01

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

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

Science.gov (United States)

2010-07-01

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

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

African Journals Online (AJOL)

Nekky Umera

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

The Dendrochronological Dating of Timber Crossings in West Jutland, Denmark

DEFF Research Database (Denmark)

Daly, Aoife

2006-01-01

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

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

Science.gov (United States)

David E. Haugen; Robert A. Harsel

2013-01-01

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

Implementing CITES regulations for timber.

Science.gov (United States)

Blundell, Arthur G

2007-03-01

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

System Reliability of Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2010-01-01

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

Dowelled structural connections in laminated bamboo and timber

OpenAIRE

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

2015-01-01

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

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

African Journals Online (AJOL)

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

Guidelines for the on-site assessment of historic timber structures

NARCIS (Netherlands)

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

2014-01-01

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

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

African Journals Online (AJOL)

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

Protection of mechanized timberings on beds dangerous for mine impacts

Energy Technology Data Exchange (ETDEWEB)

Budirsky, S

1982-01-01

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

Moment Capacity of Timber Reinforced with Punched Metal Plate Fasteners

DEFF Research Database (Denmark)

Nielsen, Jacob; Ellegaard, Peter

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

Timber Elements: Traditional and Modern Strengthening Techniques

Directory of Open Access Journals (Sweden)

Raluca Hohan

2010-01-01

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

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

Science.gov (United States)

Ronald J. Piva; Gregory J. Josten

2013-01-01

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

T-section glulam timber bridge modules : modeling and performance

Science.gov (United States)

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

1999-01-01

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

Tree-mendous Timber Evaluation

Science.gov (United States)

2004-01-01

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

Predicting moisture state of timber members in a continuously varying climate

DEFF Research Database (Denmark)

Svensson, Staffan; Turk, Goran; Hozjan, Tomaz

2011-01-01

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

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

Reliability Analysis of Timber Structures through NDT Data Upgrading

DEFF Research Database (Denmark)

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

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

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

Science.gov (United States)

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

2011-01-01

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

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

Directory of Open Access Journals (Sweden)

Jicheng Zhang

2018-05-01

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

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

Directory of Open Access Journals (Sweden)

Wilmer Espinoza

2013-08-01

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

Field investigations of historic covered timber bridges in the USA

Science.gov (United States)

James Wacker; Travis Hosteng; Brent. Phares

2012-01-01

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

Projecting national forest inventories for the 2000 RPA timber assessment.

Science.gov (United States)

John R. Mills; Xiaoping. Zhou

2003-01-01

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

Nondestructive assessment of timber bridges using a vibration-based method

Science.gov (United States)

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

2005-01-01

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

Robustness of Long Span Reciprocal Timber Structures

DEFF Research Database (Denmark)

Balfroid, Nathalie; Kirkegaard, Poul Henning

2011-01-01

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

Global timber trade pattern: the cards have changed

OpenAIRE

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

2011-01-01

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

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

Science.gov (United States)

Steven J. Beaupre; Lara E. Douglas

2012-01-01

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

Elementary and advanced modelling of the splitting strength of timber connections

NARCIS (Netherlands)

Schoenmakers, J.C.M.D.

2008-01-01

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

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

Science.gov (United States)

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

1986-01-01

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

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

Directory of Open Access Journals (Sweden)

Massimo Fragiacomo

2015-06-01

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

Robustness Analyses of Timber Structures

DEFF Research Database (Denmark)

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

2013-01-01

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

Radiation technique in density and strength testing of coniferous structural timber

International Nuclear Information System (INIS)

Dzbenski, W.; Krzosek, S.

1998-01-01

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

Timber drying kilns using solar energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-15

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

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

Science.gov (United States)

Willem W.S. van Hees

1985-01-01

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

Simplified Analytical Model for a Queen-Post Covered Timber Bridge

Science.gov (United States)

F Fanous; D. Rammer; T. Wipf

2013-01-01

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

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...

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

Science.gov (United States)

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

1992-01-01

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

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

Science.gov (United States)

2010-07-01

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

Timber resources of Ohio

Science.gov (United States)

Neal P. Kingsley; Carl E. Mayer

1970-01-01

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

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

Science.gov (United States)

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

1987-01-01

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

Development of a smart timber bridge girder with fiber optic sensors

Science.gov (United States)

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

2010-01-01

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

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...

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

DEFF Research Database (Denmark)

Lauritzen Jensen, J.

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

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

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

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

Service life assessment of timber highway bridges in USA climate zones

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2002-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

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

2009-09-01

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

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.

Multi-objective room acoustic optimization of timber folded plate structure

DEFF Research Database (Denmark)

Skov, Rasmus; Parigi, Dario; Damkilde, Lars

2017-01-01

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

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

Science.gov (United States)

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

2016-02-02

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

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

Science.gov (United States)

David N. Wear; Peter J. Parks

1994-01-01

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

Probabilistic Modeling of Graded Timber Material Properties

DEFF Research Database (Denmark)

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

2004-01-01

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

Timber designers' manual

CERN Document Server

Ozelton, E C

2008-01-01

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

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

Directory of Open Access Journals (Sweden)

David Hervieux

1996-01-01

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

Parametric Evaluation of Racking Performance of Platform Timber Framed Walls

OpenAIRE

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

2017-01-01

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

Timber resource statistics for Oregon.

Science.gov (United States)

Sally Campbell; Paul Dunham; David. Azuma

2004-01-01

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

Evaluation of recycled timber members

Science.gov (United States)

Douglas R. Rammer

1999-01-01

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

Timber management opportunities in Pennsylvania

Science.gov (United States)

Henry H. Webster

1960-01-01

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

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

International Nuclear Information System (INIS)

Giltenan, E.

1993-01-01

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

Reliability based Robustness of Timber Structures through NDT Data Updating

DEFF Research Database (Denmark)

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

2011-01-01

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

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

OpenAIRE

Hahn, Benjamin; Hatt, Fred

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-06-25

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

Robustness Assessment of Spatial Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning

2012-01-01

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

Historic timber roof structures

OpenAIRE

Magina, Miguel Jorge

2013-01-01

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

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

Science.gov (United States)

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

2005-01-01

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

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

DEFF Research Database (Denmark)

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

2013-01-01

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

Theory of timber connections with slender dowel type fasteners

DEFF Research Database (Denmark)

Svensson, Staffan; Munch-Andersen, Jørgen

2018-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

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....

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

OpenAIRE

Sene, Abdou

2001-01-01

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

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

Science.gov (United States)

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

1999-01-01

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

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

Science.gov (United States)

Bruce Hiserote; Joel Moen; Charles L. Bolsinger

1986-01-01

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

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

Science.gov (United States)

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

1982-01-01

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

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

Science.gov (United States)

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

2012-01-01

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

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

Science.gov (United States)

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

2005-01-01

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

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...

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

Science.gov (United States)

2012-01-18

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

Statistical Analysis of Data for Timber Strengths

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Hoffmeyer, P.

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

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

NARCIS (Netherlands)

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

2008-01-01

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

Framework for Robustness Assessment of Timber Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2011-01-01

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

Self-extinguishment of cross-laminated timber

NARCIS (Netherlands)

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

2016-01-01

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

Understanding Loss Deductions for Timber

Science.gov (United States)

John Greene; Michael Jacobson

1998-01-01

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

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.

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

Science.gov (United States)

L. E. Hislop; M. A. Ritter

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

Space-time modeling of timber prices

Science.gov (United States)

Mo Zhou; Joseph Buongriorno

2006-01-01

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

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

Directory of Open Access Journals (Sweden)

Kolin Branko

2012-01-01

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

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

International Nuclear Information System (INIS)

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

2001-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

1966-01-01

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

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

Science.gov (United States)

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

1989-01-01

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

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

Science.gov (United States)

2010-07-01

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

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...

Pocket Checklists of Indonesian timber trees

NARCIS (Netherlands)

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

1984-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

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

NARCIS (Netherlands)

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

2015-01-01

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

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

OpenAIRE

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

2016-01-01

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

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

Science.gov (United States)

Holý, Milan; Vráblík, Lukáš; Petřík, Vojtěch

2017-09-01

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

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

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2011-01-01

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

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

OpenAIRE

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

2007-01-01

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

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

Directory of Open Access Journals (Sweden)

Chiotan Corina

2015-12-01

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

A cut above: building the market for fair trade timber

Energy Technology Data Exchange (ETDEWEB)

MacQueen, Duncan

2008-02-15

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

Non-timber forest products in Hawaii

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

2010-07-01

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

Robustness Analysis of Typologies of Reciprocal Timber Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Parigi, Dario

2013-01-01

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

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

DEFF Research Database (Denmark)

Mishnaevsky, Leon; Freere, Peter; Sinha, Rakesh

2011-01-01

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

Components interaction in timber framed masonry structures subjected to lateral forces

Directory of Open Access Journals (Sweden)

Andreea DUTU

2012-07-01

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

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

Science.gov (United States)

Eric J. Gustafson

1996-01-01

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

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

Science.gov (United States)

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

2006-01-01

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

Influence of Compression Stresses on Timber Potentials of ...

African Journals Online (AJOL)

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

Timber resource of Minnesota's Prairie unit, 1977.

Science.gov (United States)

Jerold T. Hahn; W. Brad Smith

1980-01-01

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

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

Directory of Open Access Journals (Sweden)

Mehrab Madhoushi

2013-01-01

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

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

Science.gov (United States)

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

2002-07-01

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

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

NARCIS (Netherlands)

Kistenkas, F.H.

2013-01-01

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

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

Science.gov (United States)

2010-07-01

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

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

Directory of Open Access Journals (Sweden)

Mattias Boman

2012-08-01

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

Sustainability and Security: Timber Certification in Asia-Pacific Region

Directory of Open Access Journals (Sweden)

Antonina Ivanova

2008-10-01

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

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

Directory of Open Access Journals (Sweden)

Yupeng Wang

2016-06-01

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

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.

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.

Extant contents of chromium, copper and arsenic in waste CCA-treated timber

International Nuclear Information System (INIS)

Chiba, Keiko; Uchida, Shinpei; Honma, Yoshinori; Sera, Koichiro; Saitoh, Katsumi

2009-01-01

The segregation and disposal of chromated copper arsenate (CCA)-treated wood waste when recycling building waste materials is a serious issue. We examined the contents of CCA preserved cedar timber by PIXE analysis. CCA preserved timber contained large amounts of these metals both on the surface and core of the wood. The ratio of chromium, copper and arsenic contained on the surface was 1:2:1, and in contrast, the ratio in the core was 1:1:2. In other words, the arsenic content was highest in the core. Moreover, the chemical form of arsenic in both parts of the wood was only inorganic arsenic; the same form of arsenic in preservative components known as carcinogenic substances. These findings mean that the complete separation of waste CCA preserved timber from construction and demolition wood is needed. (author)

Commercial lumber, round timbers, and ties

Science.gov (United States)

David E. Kretschmann

2010-01-01

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

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

Science.gov (United States)

Eric J. Gustafson

1998-01-01

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

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

CSIR Research Space (South Africa)

Cairns, RI

2000-01-01

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

26 CFR 1.611-3 - Rules applicable to timber.

Science.gov (United States)

2010-04-01

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

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

Science.gov (United States)

2010-07-01

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

Projecting Timber Inventory at the Product Level

Science.gov (United States)

Lawrence Teeter; Xiaoping Zhou

1999-01-01

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

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

Science.gov (United States)

2010-07-01

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

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

International Nuclear Information System (INIS)

Cinotti, B.

2007-01-01

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

Fire resistance in American heavy timber construction history and preservation

CERN Document Server

Heitz, Jesse

2016-01-01

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

Timber joints under long-term loading

DEFF Research Database (Denmark)

Feldborg, T.; Johansen, M.

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

Grading timber and glued structural members

Science.gov (United States)

David E. Kretschmann; Roland Hernandez

2006-01-01

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

Residual load carrying capacity of timber joints

NARCIS (Netherlands)

Kuilen, J.W.G. van de

1999-01-01

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

Forests, timber and rural livelihoods

DEFF Research Database (Denmark)

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

2015-01-01

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

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

African Journals Online (AJOL)

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

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

Science.gov (United States)

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

2011-01-01

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

36 CFR 223.85 - Noncompetitive sale of timber.

Science.gov (United States)

2010-07-01

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

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

Directory of Open Access Journals (Sweden)

Tomáš Čejka

2015-12-01

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

Roof timber for fortifying mining works

Energy Technology Data Exchange (ETDEWEB)

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

1981-05-15

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

ECOLOGICAL EFFECT OF TIMBER EXPRACTION IN OHIMINI LGA ...

African Journals Online (AJOL)

Shima

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

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.

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

Directory of Open Access Journals (Sweden)

Yunsong Han

2017-12-01

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

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

Directory of Open Access Journals (Sweden)

Kenichi Azuma

2016-12-01

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

Experimental verification of a weak zone model for timber in bending

DEFF Research Database (Denmark)

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

1997-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

William G. Luppold; Matthew S. Bumgardner

2018-01-01

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

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

Science.gov (United States)

Rodacki, Konrad

2017-12-01

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

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

Directory of Open Access Journals (Sweden)

Manojlović Dragan

2016-01-01

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

epidemiology of eye diseases among timber workers in owerri

African Journals Online (AJOL)

LIVINGSTON

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

Stiffness analysis of glued connection of the timber-concrete structure

Science.gov (United States)

Daňková, Jana; Mec, Pavel; Majstríková, Tereza

2016-01-01

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

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

International Nuclear Information System (INIS)

Kaye Thwe Kywe Aye; Win Kyi; Tin Hlaing

2001-01-01

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

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

NARCIS (Netherlands)

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

2013-01-01

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

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

Science.gov (United States)

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

2011-04-01

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

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

DEFF Research Database (Denmark)

Pečenko, Robert; Huč, Sabina; Turk, Goran

2014-01-01

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

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

African Journals Online (AJOL)

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

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

Rodney J. Nakamoto

1998-01-01

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

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

Directory of Open Access Journals (Sweden)

Irina Anatolyevna Kislukhina

2018-03-01

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

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

Science.gov (United States)

W. Brad Smith

1984-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

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.

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...

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

Science.gov (United States)

2010-01-01

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

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

Science.gov (United States)

2010-07-01

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

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

Science.gov (United States)

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

2000-01-01

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

The privately owned timber resources of western Oregon.

Science.gov (United States)

Donald R. Gedney

1983-01-01

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

Determining modulus of elasticity of ancient structural timber

Science.gov (United States)

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

2011-01-01

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

The Effect of Urban Sprawls on Timber Harvesting

Science.gov (United States)

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

1998-01-01

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

Impact of timber production and transport costs on stand management

Science.gov (United States)

Chris B. LeDoux; Chris B. LeDoux

1988-01-01

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

Montana's forest products industry and timber harvest, 2004

Science.gov (United States)

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

2008-01-01

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

Timber resource statistics for Washington, January 1, 1973.

Science.gov (United States)

Patricia M. Bassett; Grover A. Choate

1974-01-01

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

An improved method for calculating force distributions in moment-stiff timber connections

DEFF Research Database (Denmark)

Ormarsson, Sigurdur; Blond, Mette

2012-01-01

An improved method for calculating force distributions in moment-stiff metal dowel-type timber connections is presented, a method based on use of three-dimensional finite element simulations of timber connections subjected to moment action. The study that was carried out aimed at determining how...... the slip modulus varies with the angle between the direction of the dowel forces and the fibres in question, as well as how the orthotropic stiffness behaviour of the wood material affects the direction and the size of the forces. It was assumed that the force distribution generated by the moment action...

Using experimental modal analysis to assess the behaviour of timber elements

Science.gov (United States)

Kouroussis, Georges; Fekih, Lassaad Ben; Descamps, Thierry

2018-03-01

Timber frameworks are one of the most important and widespread types of structures. Their configurations and joints are usually complex and require a high level of craftsmanship to assemble. In the field of restoration, a good understanding of the structural behaviour is necessary and is often based on assessment techniques dedicated to wood characterisation. This paper presents the use of experimental modal analysis for finite element updating. To do this, several timber beams in a free supported condition were analysed in order to extract their bending natural characteristics (frequency, damping and mode shapes). Corresponding ABAQUS finite element models were derived which included the effects of local defects (holes, cracks and wood nodes), moisture and structural decay. To achieve the modal updating, additional simulations were performed in order to study the sensitivity of the mechanical parameters. With the intent to estimate their mechanical properties, a procedure of modal updating was carried out in MatLab with a Python script. This was created to extract the modal information from the ABAQUS modal analysis results to be compared with the experimental results. The updating was based on a minimum of unconstrained multivariable function using a derivative-free method. The objective function was selected from the conventional comparison tools (absolute or relative frequency difference, and/or modal assurance criterion). This testing technique was used to determine the dynamic mechanical properties of timber beams, such as the anisotropic Young's Moduli and damping ratio. To verify the modulus, a series of static 4-point bending tests and STS04 classifications were conducted. The results also revealed that local defects have a negligible influence on natural frequencies. The results demonstrate that this assessment tool offers an effective method to obtain the mechanical properties of timber elements, especially when on-site and non-destructive techniques are

MODAL ANALYSIS OF REAL TIMBER FRAME HOUSES WITH DIFFERENT INSULATION MATERIALS

Directory of Open Access Journals (Sweden)

Marcin Szczepański

2016-09-01

Full Text Available The aim of this article is to present the results of a numerical modal analysis of two actual structures of timber frame buildings and the different behaviour due to the used insulation material. One model of the timber structure was filled with mineral wool, while the other with polyurethane foam. During the modal analysis, eigenvalues for both models have been determined. The results of the analysis clearly show the increase of stiffness and damping properties of skeletal constructions achieved by the use of polyurethane foam as the skeleton filling. The numerical model was based on prior experimental test on real scale single frame elements, therefore the result can be assumed to be adequate.

Chapter 1: CLT Introduction to cross-laminated timber

Science.gov (United States)

Sylvan Gagnon; E.M.(Ted) Bilek; Lisa Podesto; Pablo Crespell

2013-01-01

Cross-laminated timber ( CLT), a new generation of engineered wood product developed initially in Europe, has been gaining increased popularity in residential and non-residential applications in several countries. Many impressive low- and mid-rise buildings built around the world using CLT showcase the many advantages this product has to offer to the construction...

Global timber investments, wood costs, regulation, and risk

Science.gov (United States)

F. Cubbage; S. Koesbandana; P Mac Donagh; R. Rubilar; G Balmelli; V. Morales Olmos; R. De La Torre; M. Murara; V.A. Hoeflich; H. Kotze; R Gonzalez; O. Carrero; G. Frey; T. Adams; J. Turner; R. Lord; J. Huang; C. MacIntyre; Kathleen McGinley; R. Abt; R. Phillips

2010-01-01

We estimated financial returns and wood production costs in 2008 for the primary timber plantation species. Excluding land costs, returns for exotic plantations in almost all of South America e Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay e were substantial. Eucalyptus species returns were generally greater than those for Pinus species in each...

Forest soil biology-timber harvesting relationships: a perspective

Science.gov (United States)

M. F. Jurgensen; M. J. Larsen; A. E. Harvey

1979-01-01

Timber harvesting has a pronounced effect on the soil microflora by wood removal and changing properties. This paper gives a perspective on soil biology-harvesting relationships with emphasis on the northern Rocky Mountain region. Of special significance to forest management operations are the effects of soil micro-organisms on: the availability of soil nutrients,...

75 FR 21577 - Rogue River-Siskiyou National Forest, Powers Ranger District, Coos County, OR; Eden Ridge Timber...

Science.gov (United States)

2010-04-26

... Plan, page C-39). Specifically for the Eden Ridge Timber Sales project, Needs include: Improvement of... District, Coos County, OR; Eden Ridge Timber Sales AGENCY: Forest Service, USDA. ACTION: Notice of intent... Forest's Probable Sale Quantity. The planning area is located approximately four (4) air miles southeast...

Profitability of timber harvesting and timber transportation enterprises

International Nuclear Information System (INIS)

Rajamaeki, J.

1996-01-01

In co-operation with the major companies contracting out forestry work and Statistics Finland, Metsaeteho carried out a project with the objective of analysing the economic profitability of timber harvesting and transportation enterprises in 1994. The calculation of profitability was based on utilisation of last livelihoods taxation data (EVR) that Statistics Finland was in possession of. The basic material comprised data that the companies contracting out forestry work had full-time entrepreneurs. There were 255 forestry machine contractor enterprises and 270 trucking enterprises. Statistics Finland was responsible for computations of the results of the project. The calculation of the indicators of profitability was based on the recommendations of Yritystutkimusneuvottelukunta, a committee looking into the functioning of enterprises. The year 1994 was a good year from the viewpoint of profitability of both forestry machine contractors as well as trucking enterprises. With full depreciations and salary adjustments attended to, both enterprise groups still showed a mean profitability of ca. 8 %. The yield of invested capital was ca. 25 %. The differences in profitability among enterprises were great in both groups and in different parts of the country

In situ assessment of structural timber elements of a historic building by infrared thermography and ultrasonic velocity

Science.gov (United States)

Kandemir-Yucel, A.; Tavukcuoglu, A.; Caner-Saltik, E. N.

2007-01-01

The infrared thermography (IRT) and the ultrasonic velocity measurements (UVM) promise to be particularly important to assess the state of deterioration and the adequacy of the boundary and microclimatic conditions for timber elements. These non-destructive methods supported by laboratory analyses of timber samples were conducted on a 13th century monument, Aslanhane Mosque in Ankara, Turkey. The combined interpretation of the results was done to assess the condition of structural timber elements in terms of their state of preservation, the dampness problems and the recent incompatible repairs affecting them. Results indicated that moist areas in the structure were associated with roof drainage problems and the repairs undertaken with cement-based mortars and plasters and oil-based paints. Juxtaposition of the IRT and UVM together with laboratory analyses was found to be useful to assess the soundness of timber, enhanced the accuracy and effectiveness of the survey and facilitated to build up the urgent and long-term conservation programs.

Development of flexural vibration inspection techniques to rapidly assess the structural health of timber bridge systems

Science.gov (United States)

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

2005-01-01

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

26 CFR 1.631-2 - Gain or loss upon the disposal of timber under cutting contract.

Science.gov (United States)

2010-04-01

... cutting contract. 1.631-2 Section 1.631-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... loss upon the disposal of timber under cutting contract. (a) In general. (1) If an owner disposes of... deemed to be the date such timber is cut. However, if payment is made to the owner under the contract for...

Idaho's forest products industry and timber harvest, 2011

Science.gov (United States)

Eric A. Simmons; Steven W. Hayes; Todd A. Morgan; Charles E. Keegan; Chris Witt

2014-01-01

This report traces the flow of Idaho’s 2011 timber harvest through the primary industries; provides a description of the structure, capacity, and condition of Idaho’s industry; and quantifies volumes and uses of wood fiber. Historical wood products industry trends are discussed, as well as changes in harvest, production, employment, and sales.

36 CFR 223.118 - Appeal process for small business timber sale set-aside program share recomputation decisions.

Science.gov (United States)

2010-07-01

... appeal: (i) The appellant's name, mailing address, and daytime telephone number; (ii) The title or type... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Appeal process for small... FOREST SYSTEM TIMBER Timber Sale Contracts Contract Administration § 223.118 Appeal process for small...

Experimental and finite element study of the effect of temperature and moisture on the tangential tensile strength and fracture behavior in timber logs

DEFF Research Database (Denmark)

Larsen, Finn; Ormarsson, Sigurdur

2014-01-01

Timber is normally dried by kiln drying, in the course of which moisture-induced stresses and fractures can occur. Cracks occur primarily in the radial direction due to tangential tensile strength (TSt) that exceeds the strength of the material. The present article reports on experiments and nume......Timber is normally dried by kiln drying, in the course of which moisture-induced stresses and fractures can occur. Cracks occur primarily in the radial direction due to tangential tensile strength (TSt) that exceeds the strength of the material. The present article reports on experiments...... and numerical simulations by finite element modeling (FEM) concerning the TSt and fracture behavior of Norway spruce under various climatic conditions. Thin log disc specimens were studied to simplify the description of the moisture flow in the samples. The specimens designed for TS were acclimatized...... to a moisture content (MC) of 18% before TSt tests at 20°C, 60°C, and 90°C were carried out. The maximum stress results of the disc simulations by FEM were compared with the experimental strength results at the same temperature levels. There is a rather good agreement between the results of modeling...

Essays on the economics of British Columbian timber policy

NARCIS (Netherlands)

Niquidet, Kurt

2007-01-01

This thesis examines the process of institutional change in British Columbia’s timber sector. It is composed of a series of essays which highlight the underlying political and economic factors that have shaped past and current reforms. Taking center stage in the analysis, are the resource rents

Timber beams loaded perpendicular to grain by multiple connections

NARCIS (Netherlands)

Leijten, A.J.M.; Schoenmakers, J.C.M.

2014-01-01

In timber structures, beams which are loaded perpendicular to grain by connections along the span may fail by splitting, resulting in the collapse of the beam. In the past, empirical, semi-empirical and fracture mechanical models have been developed aiming at predicting the splitting failure load.

78 FR 73818 - Information Collection; Timber Sale Contract Operations and Administration

Science.gov (United States)

2013-12-09

.... Forest Service officers collect the information from contractors who may be individuals, private sector... timber and other forest products, in order to: (1) Plan and schedule contract administration workloads...

Seismic Strengthening of Carpentry Joints in Traditional Timber Structures

International Nuclear Information System (INIS)

Parisi, Maria A.; Cordie, Cinzia; Piazza, Maurizio

2008-01-01

The static and dynamic behavior of timber structures largely depends on their connections. In traditional timber construction, elements are usually connected with carpentry joints based on contact pressure and friction, often with only minor reinforcement generically intended to avoid disassembling. In current practice, interventions for the upgrading of carpentry joints are mainly based on empirical knowledge according to tradition. Often they produce a general strengthening of the connection, but are not specific for the case of seismic action. Strengthening on heuristic bases may be only partially effective or possibly disproportioned. The behavior of the carpentry joints most used in roof structures is examined. The birdsmouth joint, connecting rafters to the tie beam, has been studied first, characterizing its behavior numerically and experimentally in monotonic and cyclic conditions. Other forms of the rafter-to-tie connection, the double notch joint and the case of parallel rafters, are discussed. Some general criteria for the seismic strengthening of these joints are presented

Seismic Strengthening of Carpentry Joints in Traditional Timber Structures

Science.gov (United States)

Parisi, Maria A.; Cordié, Cinzia; Piazza, Maurizio

2008-07-01

The static and dynamic behavior of timber structures largely depends on their connections. In traditional timber construction, elements are usually connected with carpentry joints based on contact pressure and friction, often with only minor reinforcement generically intended to avoid disassembling. In current practice, interventions for the upgrading of carpentry joints are mainly based on empirical knowledge according to tradition. Often they produce a general strengthening of the connection, but are not specific for the case of seismic action. Strengthening on heuristic bases may be only partially effective or possibly disproportioned. The behavior of the carpentry joints most used in roof structures is examined. The birdsmouth joint, connecting rafters to the tie beam, has been studied first, characterizing its behavior numerically and experimentally in monotonic and cyclic conditions. Other forms of the rafter-to-tie connection, the double notch joint and the case of parallel rafters, are discussed. Some general criteria for the seismic strengthening of these joints are presented.

Simulating Harvest Schedule for Timber Management and Multipurpose Management in Teak Plantations

Directory of Open Access Journals (Sweden)

Tatang Tiryana

2016-04-01

Full Text Available Sustainable management of teak plantations in Java requires an improvement of the existing yield regulation method to optimize multiple benefits of the plantations at risk of stand destruction. This study was therefore aimed to formulate an alternative harvest scheduling model that integrates risk of stand destruction for supporting multipurpose management of teak plantations. The proposed model used a state-space planning model to simulate the dynamic of plantations due to timber harvesting and stand destruction, and then sought optimal solutions for 2 management scenarios, i.e. timber management that optimized total harvest volume and multipurpose management that optimized net present value (NPV while increasing carbon stocks. Using a case study on a typical teak plantation, this study confirmed that increasing destruction rates reduced harvest volumes, NPV, carbon stocks, and resulted in imbalanced ending age-class structures. Reducing cutting-age limit increased harvest volumes and NPV, but it also reduced carbon stocks of the plantations. Although the multipurpose management generated lower financial benefit, it maintained carbon stocks and produced better ending age-class structures compared to timber management. The proposed harvest scheduling model provides a useful planning tool for managing teak plantations.

An experimental study on damage detection of structures using a timber beam

International Nuclear Information System (INIS)

Choi, Fook Choon; Li, Jianchun; Samali, Bijan; Crews, Keith

2007-01-01

Using vibration methods for the damage detection and structural health monitoring in bridge structures is rapidly developing. However, very little work has so far been reported on timber bridges. This paper intends to address such shortcomings by experimental investigation on a timber beam using a vibration based method to detect damage. A promising damage detection algorithm based on modal strain energy was adopted and modified to locate/evaluate damage. A laboratory investigation was conducted on a timber beam inflicted with various damage scenarios using modal tests. The modal parameters obtained from the undamaged and damaged state of the test beam were used in the computation of damage index, were then applied using a damage detection algorithm utilising modal strain energy and a statistical approach to detect location of damage. A mode shape reconstruction technique was used to enhance the capability of the damage detection algorithm with limited number of sensors. The test results and analysis show that location of damage can be accurately identified with limited sensors. The modified method is less dependent on the number of modes selected and can detect damage with a higher degree of confidence

Habitat change and restoration: responses of a forest-floor mammal species to manipulations of fallen timber in floodplain forests

Directory of Open Access Journals (Sweden)

Mac Nally, R

2002-05-01

Full Text Available In forests and woodlands, fallen timber (logs and large branches is an important habitat element for many species of animals. Fallen timber has been systematically stripped in many forests, eliminating an important structural element. This study describes results of a ‘meso-scale’ experiment in which fallen timber was manipulated in a floodplain forest of the Murray River in south-eastern Australia. A thousand tons of wood were redistributed after one-year’s pre-manipulation monitoring, while a further two-year’s post-manipulation monitoring was conducted. The response of the main forest-floor small-mammal species, the Yellow-footed Antechinus Antechinus flavipes, to alterations of fallen-wood loads is documented. Results of the experiment will help to frame guidelines for fallen-timber management in these extensive floodplain forests.

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...

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.

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)

Form Exploration of Folded Plate Timber Structures based on Performance Criteria

DEFF Research Database (Denmark)

Falk, Andreas; Buelow, Peter Von

2011-01-01

This paper presents an explorative study on applications of cross-laminated timber (CLT) elements in shell structures. Previous studies of plate tensegrity, folded plate roofs interacting with stabilising steel-based systems and studies inspired by origami show a widening range of possibilities...... to develop timber-based shells. Steadily rising interest in rationality during pre-fabrication, transport and on-site construction in contemporary industrialised production increases the competitiveness of CLT-based elements and systems and the architectural applications are getting more common and more...... experimental. Folded plate structures which are the focus of this paper present several issues of structural importance – potential mechanisms, subdivision of surfaces etc. – and the hereby presented study aims at exploring developed typologies, using computer tools for developed optimisation procedures...

Timber resource of Michigan's Southern Lower Peninsula Unit, 1980.

Science.gov (United States)

Jerold T. Hahn

1982-01-01

The fourth inventory of the timber resource of Michigan's Southern Lower Peninsula Survey Unit shows a 12% decline in commercial forest area and a 26% gain in growing-stock volume between 1966 and 1980. Presented are highlights and statistics on area, volume, growth, mortality, removals, utilization, and biomass.

36 CFR 261.6 - Timber and other forest products.

Science.gov (United States)

2010-07-01

... such product is identified as required in such permit or contract. (f) Selling or exchanging any timber... 74 FR 26091, June 1, 2009, the amendment was delayed indefinitely. For the convenience of the user..., memorandum of agreement, memorandum of understanding, or personal-use authorization (f) Selling or exchanging...

Gender analysis of non-timber forest products (NTFPs) collection ...

African Journals Online (AJOL)

Millions of people, especially those living in rural areas in developing countries collect Non-Timber Forest products (NTFPs) daily. Women are known to play a prominent role in forestry and agricultural production in Nigeria despite not been captured as economically productive. This work looked into gender dimension ...

Efficiency and precision for estimating timber and non-timber attributes using Landsat-based stratification methods in two-phase sampling in northwest California

Science.gov (United States)

Antti T. Kaartinen; Jeremy S. Fried; Paul A. Dunham

2002-01-01

Three Landsat TM-based GIS layers were evaluated as alternatives to conventional, photointerpretation-based stratification of FIA field plots. Estimates for timberland area, timber volume, and volume of down wood were calculated for California's North Coast Survey Unit of 2.5 million hectares. The estimates were compared on the basis of standard errors,...

Analysis of the Strength of Timber and Glulam Timber Beams with Steel Reinforcement

Directory of Open Access Journals (Sweden)

Arie Putra Usman

2015-12-01

Full Text Available Indonesia is a tropical country with abundant tropical timber that can be used as a building material. Wood is a renewable material, thus making it an environmentally friendly construction material. However, the dimensional limitations of solid wood may pose problems in structural constructions. Wood material also has some disadvantages, such as brittle failure. However, the ductility of wood can be increased because of plasticity occurring in the compression zone. Wood material with good ductility can be obtained by reinforcing it in the tensile zone. This study is about the strength of wood material for use as a material for structural elements. Based on the analytical findings, the bending capacity of wood can be improved by adding reinforcements to the tensile zone.

structural reliability of the nigerian grown abura timber bridge beam

African Journals Online (AJOL)

ENGR. J. I. AGUWA

2013-07-02

Jul 2, 2013 ... Structural analysis and deterministic design of a timber bridge beam using the Nigerian ... practice especially when it involves naturally occuring materials .... the beam due to distributed loads is; from [15]. (4). It is assumed that ...

Empowering Women and Ethnic Minority Groups to Collectively Market non Timber Forest Products from Community Forests in Cameroon

NARCIS (Netherlands)

Eijnatten, van Judith; Mala, William Armand; Ingram, V.J.; Belibi, M.B.

2016-01-01

Community forestry (CF) was introduced in Cameroon in 1994 as a way to reduce poverty and enhance sustainable forest management. CF activities have primarily focused on timber exploitation rather than non-timber forest product (NTFP) collection processing or marketing. The study reports on a two

2nd International Conference on Historic Earthquake-Resistant Timber Frames in the Mediterranean Area

CERN Document Server

Machado, José; Costa, Alfredo; Candeias, Paulo; Ruggieri, Nicola; Catarino, José

2016-01-01

This book presents a selection of the best papers from the HEaRT 2015 conference, held in Lisbon, Portugal, which provided a valuable forum for engineers and architects, researchers and educators to exchange views and findings concerning the technological history, construction features and seismic behavior of historical timber-framed walls in the Mediterranean countries. The topics covered are wide ranging and include historical aspects and examples of the use of timber-framed construction systems in response to earthquakes, such as the gaiola system in Portugal and the Bourbon system in southern Italy; interpretation of the response of timber-framed walls to seismic actions based on calculations and experimental tests; assessment of the effectiveness of repair and strengthening techniques, e.g., using aramid fiber wires or sheets; and modelling analyses. In addition, on the basis of case studies, a methodology is presented that is applicable to diagnosis, strengthening and improvement of seismic performance ...

Timbered masonry for earthquake resistance in Europe

OpenAIRE

Dutu, A.; Gomes Ferreira, J.; Guerreiro, L.; Branco, F.; Gonçalves, A. M.

2012-01-01

Europe is a continent that is subject to significant seismic activity. Thus, the buildings’ seismic behaviour must be analysed, including not only the new structures, designed under more rigorous codes, but also older ones. This article examines a traditional type of building that uses timber frame/masonry, which is found in Portugal, Turkey, France, England, Greece, Romania, Italy, Spain, Germany and Scandinavia. Although the structures differ in terms of construction details, their struc...

Timbered masonry for earthquake resistance in Europe

OpenAIRE

Dutu, A.; Gomes Ferreira, J.; Guerreiro, L.; Branco, F.; Gonçalves, A. M.

2012-01-01

Europe is a continent that is subject to significant seismic activity. Thus, the buildings’ seismic behaviour must be analysed, including not only the new structures, designed under more rigorous codes, but also older ones. This article examines a traditional type of building that uses timber frame/masonry, which is found in Portugal, Turkey, France, England, Greece, Romania, Italy, Spain, Germany and Scandinavia. Although the structures differ in terms of construction details, their str...

Non-timber forest products in sustainable forest management

Science.gov (United States)

James L. Chamberlain; A.L. Hammett; Philip A. Araman

2001-01-01

The forests of Southern United States are the source of many non-timber forest products (NTFPs). The collection, trade and use of these products have been important to rural economies since Europeans settled in this country. At the same time the plants from which these products originate are crucial to healthy ecosystems. Over the last decade, the market demand and the...

The supply and demand situation for oak timber

Science.gov (United States)

Kenneth L. Quigley

1971-01-01

Twenty oak species in the eastern United States account for one-third of the hardwood sawtimber volume and almost 10 percent of both hardwood and softwood growing-stock volume. The oak-hickory and oak-pine forest types occupy about 38 percent of the forest land in the eastern United States. Oak timber volume is increasing. Annual growth exceeds annual removals by about...

Timber market research, private forests, and policy rhetoric

Science.gov (United States)

David N. Wear; Jeffrey P. Prestemon

2004-01-01

The development of the profession and practice of forestry in the United States can be linked to urgent concerns regarding timber shortages in the late 19th century (Williams 1989). These were based largely on perceived failures of forest landowners to protect or invest enough in the productive capacity of their forests (Manthy 1977). The South, as the only major...

Timber resource statistics for Oregon, January 1, 1973.

Science.gov (United States)

Patricia M. Bassett; Grover A. Choate

1974-01-01

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

Emissions from prescribed burning of timber slash piles in Oregon.

Science.gov (United States)

Emissions from burning piles of post-harvest timber slash (Douglas fir) in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matte...

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.

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...

Marketing of Non-Timber Forest Products in Kajola Local ...

African Journals Online (AJOL)

Marketing of Non-Timber Forest Products in Kajola Local Government Area of Oyo State, Nigeria. ... International Journal of Tropical Agriculture and Food Systems ... The results of the marketing margin reveal that charcoal commanded the highest margin of ₦2500, followed by bush meat (₦300), while wrapping had the ...

Modeling ground-based timber harvesting systems using computer simulation

Science.gov (United States)

Jingxin Wang; Chris B. LeDoux

2001-01-01

Modeling ground-based timber harvesting systems with an object-oriented methodology was investigated. Object-oriented modeling and design promote a better understanding of requirements, cleaner designs, and better maintainability of the harvesting simulation system. The model developed simulates chainsaw felling, drive-to-tree feller-buncher, swing-to-tree single-grip...

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...

Process and device for producing a timber gear case for tunnels and mines

Energy Technology Data Exchange (ETDEWEB)

Foik, A

1977-09-08

A device is described for producing a timber gear case for tunnels and mines. Plank shaped pillars, partly overlapping one another are driven in parallel planes at an angle to the tunnel axis, close together and advancing relative to the face. The pillars are taken through supports erected one after the other in the longitudinal direction of the tunnel, and are supported. The process can be extended by producing a timber gear case to secure any type of underground space. The process produces further mechanisation of tunnelling and mining and also ensures greater safety for the miners.

Condition Assessment of the Timber Structures of a Century-Old Industrial Building Using a Nondestructive Inspection Procedure

Science.gov (United States)

Xiping Wang; Marko Teder; James Wacker

2013-01-01

This paper reports an in situ inspection project conducted on heavy timber structures of a century-old industrial building at a paper manufacturing facility. A nondestructive inspection procedure was employed to evaluate the true condition of the heavy timbers that serve as the main framing structure of the building. The on-site investigation involved monitoring of the...

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

Assessments of the market prospects for Myanmar timber

International Nuclear Information System (INIS)

Tin-Maung-Win

2001-08-01

Myanmar has been exporting teak and hardwood logs and conversions for a long time. It is found that there are three types of market situations with regard to logs and conversions. They are: situation that the demand of the market is strong; situation that the market has just picked up; situation that the demand is sluggish. Countries where the demand is strong are India, Thailand and Malaysia. Countries where the market is picking up are Singapore, PRC and the Middle East. Similarly, Europe's market is on the rise. Japan, Korea, Hong Kong and Pakistan markets are sluggish temporarily. North America's market can be said to be sluggish too. It is found that Australia has not been buying timber directly from Myanmar for the last few years and that it may not be in a position to buy Myanmar teak voluminously in the near future either. This paper is therefore a report focused on Myanmar Timber Enterprises' endeavour to earn foreign exchange in US Dollars and its assessment and evaluation of the market. The international market situation is studied and each country's situation focused on and presented. (author)

75 FR 63419 - Surety Bond Guarantee Program; Timber Sales

Science.gov (United States)

2010-10-15

... with the contract terms. 36 CFR 223.35. Generally, the Performance Bond, as defined in 13 CFR 115.10, ensures that the Principal, as defined in 13 CFR 115.10, complies with all contract terms and conditions... timber sale contracts awarded by the Federal Government or other public or private landowners. DATES...

Forest ecosystem services: Provisioning of non-timber forest products

Science.gov (United States)

James L. Chamberlain; Gregory E. Frey; C. Denise Ingram; Michael G. Jacobson; Cara Meghan Starbuck Downes

2017-01-01

The purpose of this chapter is to describe approaches to calculate a conservative and defensible estimate of the marginal value of forests for non-timber forest products (NTFPs). 'Provisioning" is one of four categories of benefits, or services that ecosystems provide to humans and was described by the Millennium Ecosystem Assessment as 'products...

Hydropower build-up and the timber floating in Northern Finland after the Second World War

Energy Technology Data Exchange (ETDEWEB)

Haenninen, N. (Univ. of Oulu, Thule Inst. (Finland)). email: niko.hanninen@oulu.fi

2009-07-01

During the Second World War, Finland lost a substantial amount of built and yet un-built hydropower capacity to Soviet Union due to loss of Karelia. The most significant energy user at the time was the forest industry, especially paper and pulp mills, which had to replace this loss and to secure uninterrupted supply of energy in the future; otherwise the industry could not realise their expansion plans. One solution was to harness the still untouched northern waters for the service of the industry and society in large. However, these rivers served already the forest industry in another way, as transport routes in floating of timber. Vast waterways had made the emergence of forest industry in Finland possible. Transportation of timber from distant forests, located more than hundreds of kilometres away from the mills, was possible using rivers and lakes. Especially in Northern Finland the industry had to rely on floating as the railway network was less extensive than in some other parts of the country. The objective of this paper is to study closer, how the emergence of vast hydropower dams in these northern rivers from late 1940's to 1970's changed the transportation of timber. Road transportation in particular could not compete with floating because of their higher costs and the lack of suitable trucks and roads, but this changed after the war. Despite the fact that expanding industries consumed more and more timber, the role of floating decreased. But how did these ratios change during this period? Did the build-up of hydropower plants contribute to this shift of timber transportations from waterways to the land? Salmon and logs did not fit on the same river, the fishermen had to yield in the end. Did the hydropower plants do the same to the floaters

Assessment of longitudinal modulus of elasticity in structural elements of Pinus Caribaea timber beams

Directory of Open Access Journals (Sweden)

André Luis Christoforo

2012-05-01

Full Text Available The current standard NBR 7190/1997 (Project of Timber Structures makes no reference to tests for determining the stiffness and strength in parts of structural lumber; restricting the analysis to bodies-of-tests with small dimensions and without defects. This paper presents an alternative method to determine the longitudinal modulus of elasticity in timber beams, based on the Finite Element Method, as well as the Inverse Analysis Method with an optimization technique. Results show that the methodology proposed by the Brazilian standard can also be applied to pieces of structural dimensions.

Influence of growth stresses and material properties on distortion of sawn timber - numerical investigation

DEFF Research Database (Denmark)

Johansson, Marie; Ormarsson, Sigurdur

2009-01-01

The board distortion that occurs during the sawing and the drying process causes major problems in the utilisation of sawn timber. The distortion is highly influenced by parameters such as spiral grain angle, modulus of elasticity, shrinkage, growth stresses and sawing pattern. In this study...... a finite element simulation of log sawing and timber drying was performed to study how these parameters interact to affect board distortion. A total of 81 logs with different material combinations were simulated. From each simulated log four boards with different annual ring orientation were studied...

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’’...

31 CFR 593.205 - Prohibition on the importation of any round log or timber product originating in Liberia.

Science.gov (United States)

2010-07-01

... round log or timber product originating in Liberia. 593.205 Section 593.205 Money and Finance: Treasury... on the importation of any round log or timber product originating in Liberia. Except as otherwise... product originating in Liberia is prohibited. Note to § 593.205: See section 593.510, which authorizes...

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

The economic viability of smallholder timber production under expanding açaí palm production in the Amazon Estuary

Science.gov (United States)

Fortini, Lucas B.; Douglas R. Carter,

2015-01-01

Relatively little attention has been paid to the economic potentials and limitations of tropical timber production and management at smallholder scales, with the most relevant research focusing on community forestry efforts. As a rare tropical example of long-lasting small-scale timber production, in this study we explore the economics of smallholder vertically integrated timber use to better understand the activity in the context of its primary land use alternative in the Amazon Estuary, açaí palm fruit production. We use data from landowner and firm surveys, participatory monitoring of firms, and detailed forest and sawmill operation monitoring to devise financial returns models of smallholder timber micro firms and açaí palm fruit production. We then compare the economics of the two activities to better understand how differences may shape decisions at the small holder scale that impact current land use shifts in the region.

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.

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.

Accuracy in estimation of timber assortments and stem distribution - A comparison of airborne and terrestrial laser scanning techniques

Science.gov (United States)

Kankare, Ville; Vauhkonen, Jari; Tanhuanpää, Topi; Holopainen, Markus; Vastaranta, Mikko; Joensuu, Marianna; Krooks, Anssi; Hyyppä, Juha; Hyyppä, Hannu; Alho, Petteri; Viitala, Risto

2014-11-01

Detailed information about timber assortments and diameter distributions is required in forest management. Forest owners can make better decisions concerning the timing of timber sales and forest companies can utilize more detailed information to optimize their wood supply chain from forest to factory. The objective here was to compare the accuracies of high-density laser scanning techniques for the estimation of tree-level diameter distribution and timber assortments. We also introduce a method that utilizes a combination of airborne and terrestrial laser scanning in timber assortment estimation. The study was conducted in Evo, Finland. Harvester measurements were used as a reference for 144 trees within a single clear-cut stand. The results showed that accurate tree-level timber assortments and diameter distributions can be obtained, using terrestrial laser scanning (TLS) or a combination of TLS and airborne laser scanning (ALS). Saw log volumes were estimated with higher accuracy than pulpwood volumes. The saw log volumes were estimated with relative root-mean-squared errors of 17.5% and 16.8% with TLS and a combination of TLS and ALS, respectively. The respective accuracies for pulpwood were 60.1% and 59.3%. The differences in the bucking method used also caused some large errors. In addition, tree quality factors highly affected the bucking accuracy, especially with pulpwood volume.

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 ...

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...

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...

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

Directory of Open Access Journals (Sweden)

Rabidin Zairul Amin

2017-01-01

Full Text Available 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 achieved in artificial drying kilns such as conventional kiln, dehumidification kiln, solar kiln, radio frequency-vacuum, etc. The objective of this study was to evaluate the characteristics of 30 mm and 50 mm thick kekatong (Cynometra spp. timber dried using kiln drying (KD and radio frequency-vacuum drying (RFV system. The investigation involved drying time, moisture content (MC variations between and within boards, drying defects, shrinkage, and drying stress. Drying defects include checks (surface, end, and internal checks and warping (bowing, cuping, spring, and twisting. The results showed that RFV drying time was reduced to 50% compared to the KD. RFV dried boards demonstrated a more uniform MC between and within boards. Shrinkage in width and thickness, as well as tangential/radial and volumetric shrinkages were substantially less in RFV boards. The amount of cupping, bowing and spring were very low and negligible in all drying runs. There was no twisting observed in all drying methods. The number of stress-free RFV board was higher than KD. With proper procedure, the RFV technology could be used for drying heavy hardwoods which are difficult to dry in conventional kilns due to excessive drying times and degradation.

Comparison of satellite imagery from LISS-III/Resourcesat-1 and TM/Landsat 5 to estimate stand-level timber volume

Directory of Open Access Journals (Sweden)

Elias Fernando Berra

2017-01-01

Full Text Available After Landsat 5 activities were discontinued, sensors on board ResourceSat-1 satellite have been pointed as an option for Landsat series. The aim of this study is to estimate timber volume from a slash pine (Pinus elliottii Engelm. stand using images from both LISS-III/ResourceSat-1 and TM/Landsat 5 sensors, cross comparing their performances. Reflectance values from the four spectral bands considered equivalent for both sensors were compared regarding sensitivity to changes in timber volume. Trends were similar, with direct relationship in the near-infrared bands and inverse relationships in the visible and mid-infrared bands. Significant differences were only found in the equivalent band of green. Multiple linear regressions were used to select spectral bands that would better explain variations in timber volume. The best fit equations for each sensor were inverted to generate maps of timber volume, estimates which were compared at pixel and stand level. None of the scales showed significant differences between estimates generated from the two sensors. We concluded that LISS-III and TM have generally very similar performance for monitoring timber volume, and LISS-III could therefore be potentially used as a complement or substitute to Landsat series.

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.

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 ...

Non-timber forest product extraction as a productive bricolage process

NARCIS (Netherlands)

Ros-Tonen, M.; Arts, B.; van Bommel, S.; Ros-Tonen, M.; Verschoor, G.

2012-01-01

This chapter explores the usefulness of the ‘productive bricolage’ concept, coined by Croll and Parkin (1992) and further elaborated by Batterbury (2001), in understanding the role of non-timber forest products (NTFPs) in people’s livelihoods and the forested landscape. I argue that NTFP extraction

Visual Grading and Structural Properties Assessment of Large Cross-Section Pinus radiata D. Don Timber

Directory of Open Access Journals (Sweden)

Eva Hermoso Prieto

2016-04-01

Full Text Available The use of large cross-section timber for structural purposes has increased in Spain, and knowledge of its properties is strategically necessary. The Spanish visual strength-grading standard UNE 56544 (2011 efficiency applied to large cross-section structural timber was analyzed using a sample of 363 specimens of radiata pine (Pinus radiata D. Don. from the Basque Country and Catalonia, Spain. Different sizes were tested (80 × 120 × 2400 mm3, 150 × 250 × 5600 mm3, 150 × 250 × 4300 mm3, and 200 × 250 × 5000 mm3. Bending strength, modulus of elasticity, and density were obtained, and characteristic values were determined in order to assign strength class according to European standard EN 338 (2010. Knots and twists were the most relevant singularities for visual strength grading. It was concluded that large cross-section Spanish radiata pine timber was suitable for structures, and it was assigned to the C20 strength class.

Managing Commercial Tree Species for Timber Production and Carbon Sequestration: Management Guidelines and Financial Returns

Energy Technology Data Exchange (ETDEWEB)

Gary D. Kronrad

2006-09-19

A carbon credit market is developing in the United States. Information is needed by buyers and sellers of carbon credits so that the market functions equitably and efficiently. Analyses have been conducted to determine the optimal forest management regime to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. Because the potential of a forest ecosystem to sequester carbon depends on the tree species, site quality and management regimes utilized, analyses have determined how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities, discount rates, prices of carbon credits and other economic variables. The effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, the amount of carbon that can be sequestered, and the amount of timber products produced has been determined.

The structural behaviour of a pre-stressed column-beam connection as an alternative to the traditional timber joint system

NARCIS (Netherlands)

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

2009-01-01

We present a new and alternative proposition for the traditional Asian timber column-and-beam connection, using the Kusabi-Nageshi (K-N) joint system. The mechanical behaviour is complex and relies on the embedment strength of the timber, pre-stress, friction, and elastic energy storage. Using a

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 (...

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...

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...

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...

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...

Connecting non-timber forest products stakeholders to information and knowledge: A case study of an Internet web site

Science.gov (United States)

James Chamberlain; Matt Winn; A.L. Hammett

2009-01-01

Many products are harvested from forests that are not timber-based but are based on plant materials. These non-timber forest products (NTFPs) have not been fully incorporated into economic development programs, yet they provide significant monetary benefits for rural entrepreneurs. Interest in NTFPs as alternative forest enterprises and sources of additional income has...

Experimental Study on Damage Detection in Timber Specimens Based on an Electromechanical Impedance Technique and RMSD-Based Mahalanobis Distance

Directory of Open Access Journals (Sweden)

Dansheng Wang

2016-10-01

Full Text Available In the electromechanical impedance (EMI method, the PZT patch performs the functions of both sensor and exciter. Due to the high frequency actuation and non-model based characteristics, the EMI method can be utilized to detect incipient structural damage. In recent years EMI techniques have been widely applied to monitor the health status of concrete and steel materials, however, studies on application to timber are limited. This paper will explore the feasibility of using the EMI technique for damage detection in timber specimens. In addition, the conventional damage index, namely root mean square deviation (RMSD is employed to evaluate the level of damage. On that basis, a new damage index, Mahalanobis distance based on RMSD, is proposed to evaluate the damage severity of timber specimens. Experimental studies are implemented to detect notch and hole damage in the timber specimens. Experimental results verify the availability and robustness of the proposed damage index and its superiority over the RMSD indexes.

System Reliability of Timber Trusses Based on Non-Linear Structural Modelling

DEFF Research Database (Denmark)

Hansson, Martin; Ellegaard, Peter

2006-01-01

. In this paper, Monte Carlo simulations of a timber W-truss with punched metal plate fasteners (nail plates) are performed. Structural timber displays a significant variability in strength and stiffness both within and between members and is described by a statistic model calibrated against data from Norway......Structural design is today concerned with single component performance where each limit state is related to a single mode of failure of a single component. Further, in limit state codes the strength variables are related to a deterministic value (usually the 5-percentile). However, in a structure...... with a number of elements, two different effects (called system effects) can be found: - The probabilistic system effect that is based on the reduced probability that weak sections coincide with the most stressed sections. - Structural load-sharing that is the ability to redistribute load between members...

Environmentally Friendly Solution to Ground Hazards in Design of Bridges in Earthquake Prone Areas Using Timber Piles

Science.gov (United States)

Sadeghi, H.

2015-12-01

Bridges are major elements of infrastructure in all societies. Their safety and continued serviceability guaranties the transportation and emergency access in urban and rural areas. However, these important structures are subject to earthquake induced damages in structure and foundations. The basic approach to the proper support of foundations are a) distribution of imposed loads to foundation in a way they can resist those loads without excessive settlement and failure; b) modification of foundation ground with various available methods; and c) combination of "a" and "b". The engineers has to face the task of designing the foundations meeting all safely and serviceability criteria but sometimes when there are numerous environmental and financial constrains, the use of some traditional methods become inevitable. This paper explains the application of timber piles to improve ground resistance to liquefaction and to secure the abutments of short to medium length bridges in an earthquake/liquefaction prone area in Bohol Island, Philippines. The limitations of using the common ground improvement methods (i.e., injection, dynamic compaction) because of either environmental or financial concerns along with the abundance of timber in the area made the engineers to use a network of timber piles behind the backwalls of the bridge abutments. The suggested timber pile network is simulated by numerical methods and its safety is examined. The results show that the compaction caused by driving of the piles and bearing capacity provided by timbers reduce the settlement and lateral movements due to service and earthquake induced loads.

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...

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

Effects of Boreal Timber Rafting on the Composition of Arctic Driftwood

Czech Academy of Sciences Publication Activity Database

Hellmann, L.; Kirdyanov, A. V.; Büntgen, Ulf

2016-01-01

Roč. 7, č. 11 (2016), č. článku 257. ISSN 1999-4907 Institutional support: RVO:67179843 Keywords : boreal rivers * Arctic driftwood * timber logging * industrial floating * Siberia Subject RIV: GK - Forestry Impact factor: 1.951, year: 2016

Solar-assisted drying of timber at industrial scale: management paper

African Journals Online (AJOL)

While ambient air drying depends on the weather conditions, conventional hightemperature dryers cause high investments and energy costs. Up to now, solar dryers could not be established in industrial timber production, due to their insufficient drying capacity and the lack of an adequate control of the drying conditions.

Span-Dependent Distributions of the Bending Strength of Spruce Timber

DEFF Research Database (Denmark)

Ditlevsen, Ove; Källsner, Bo

2005-01-01

Tests data of bending strengths of a large number of timber beams of different spans obtained at the Swedish Institute for Wood Technology Research reveal a statistical structure that can be represented in a simple probabilistic model of series system type. A particular feature of the data from one...

Biodiversity: role of non-timber forest products in food security ...

African Journals Online (AJOL)

Non-timber forest products (NTFPS) are biological materials from the ecosystem which range from plants, parts of plants, fungi, animals and animal products that are consumed either as food, condiments, spices or medicine. NTFPS have been identified to play an important role in providing primary health and nutritional ...

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.

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; ...

RATIONAL AGGREGATION OF THE PRODUCTION LIST OF THE ECONOMIC MODEL WITH THE DETAILED TIMBER COMPLEX (ASSESSMENT ON THE BASE OF THE EXPERIMENTAL CALCULATIONS

Directory of Open Access Journals (Sweden)

Mkrtchyan G. M.

2015-09-01

Full Text Available The main principle of developing specialized model complexes is based on the approach when the detailed description of the object (the core, the main body is added by the description of the context. In addition to the above, the core of the system can be made up in turns by objects picked up from the context. Developing the models on separate subsystems of the economy, presented in details in the basic model, leads to creation of problems (equations with many variables and parameters where for the specific goals of analysis (and forecasting it is not at all obligatory to use the full-scale model. Such redundancy is unnecessary while using this model for scenario calculations in the context of “branch ” problems. The authors provide experimental calculations which allow evaluating the influence of aggregation on resulting information. Average year growth rates of production by branches of timber complex are considered as resulting information. Closeness of decisions on these indicators proves the hypothesis about possibility and rationality of such aggregation of the economic context for the timber complex.

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...

Performance of stress-laminated timber highway bridges in cold climates

Science.gov (United States)

James P. Wacker

2009-01-01

This paper summarizes recent laboratory and field data studies on thermal performance of stress-laminated timber highway bridges. Concerns about the reliability of stress-laminated deck bridges when exposed to sub-freezing temperatures triggered several investigations. Two laboratory studies were conducted to study the effects of wood species, preservative, moisture...

Ecological Survey of Valuable Non-Timber Plant Resources in Two ...

African Journals Online (AJOL)

The density and diversity of plant species producing valued non-timber products in two moist rainforests in Southeastern Nigeria were studied. The two forests are Cross-River North Forest Reserve, Cross River State and Stubbs Creek Forest Reserve, Akwa Ibom State. Twenty- three plant species with the distribution as ...

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.

Evaluation of the contributions of selected non-timber forest products ...

African Journals Online (AJOL)

Evaluation of the contributions of selected non-timber forest products to food security and income generation, in Imo State, Nigeria. ... Data were analyzed using descriptive statistics, Z-test and Foster-Greer-Thorbecke (FGT) metric. The result revealed that 98% of the respondents consumed the three NTFPs as food and ...

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 ...

Maximum Entropy in Drug Discovery

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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.

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

Chemical data and variation diagrams of igneous rocks from the Timber Mountain-Oasis Valley Caldera Complex, southern Nevada

Science.gov (United States)

Quinlivan, W.D.; Byers, F.M.

1977-01-01

Silica variation diagrams presented here are based on 162 chemical analyses of tuffs, lavas, and intrusives, representative of volcanic centers of the Timber Mountain-Oasis Valley caldera complex and cogenetic rocks of the Silent Canyon ca1dera. Most of the volcanic units sampled are shown on the U.S. Geological Survey geologic map of the Timber Mountain caldera area (I-891) and are described in U.S. Geological Survey Professional Paper 919. Early effusives of the complex, although slightly altered, are probably chemically, and petrographically, more like the calc-alkalic Fraction Tuff (Miocene) of the northern Nellis Air Force Base Bombing and Gunnery Range to the north, whereas effusives of later Miocene age, such as the Paintbrush and Timber Mountain Tuffs, are alkali-calcic.

Small Sawmills Persevere While the Majors Close: Evaluating Resilience and Desirable Timber Allocation in British Columbia, Canada

Directory of Open Access Journals (Sweden)

Evelyn W. Pinkerton

2013-06-01

Full Text Available We compared the resilience to economic shocks - such as the downturn of the U.S. housing market - of commodity sawmills, which tend to be large, and value-added specialty sawmills, which tend to be small or medium in size, that are located in one region of the province of British Columbia, Canada, as measured by their average days in operation over the last decade and during the 2007-2009 recession. Using a combination of qualitative and quantitative measures, we then examined three behavioral characteristics contributing to their different degrees of resilience: flexibility, diversity, and orientation to place. We found that the specialty mills had greater resilience over the decade because they (a contributed more jobs per volume of wood consumed and produced, (b had greater flexibility to operate further below their capacity, (c produced more diverse primary and secondary (value-added wood products, (d targeted more diverse markets, and (e did more log sorting and trading in logs of different species with other specialty mills and with local commodity mills, with whom they acted as a resilient cluster. Although all these activities resulted in more logs flowing toward their highest value use, we found that the specialty mills lacked a secure and adequate timber supply, while the major timber tenures held by the commodity mills went largely unused during the downturn. This finding suggests that, in addition to contributing to resilience within the forest products sector, more access to timber tenure by the specialty mills, or having a greater portion of timber on the open market, would result in more value being produced from publicly owned timber.

The socioeconomic status of the non-timber forest product subsector ...

African Journals Online (AJOL)

A wide spectrum of non-timber forest products (NTFPs) generally has a remarkable contribution to the household economy in rural areas. Most communities make a living either through their domestic or commercial use. The objective of this study was to review the current status of the NTFP sector and further compile an ...

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...

Guide for In-Place Treatment of Covered and Timber Bridges

Science.gov (United States)

Stan Lebow; Grant Kirker; Robert White; Terry Amburgey; H. Michael Barnes; Michael Sanders; Jeff Morrell

2012-01-01

Historic covered bridges and current timber bridges can be vulnerable to damage from biodeterioration or fire. This guide describes procedures for selecting and applying in-place treatments to prevent or arrest these forms of degradation. Vulnerable areas for biodeterioration in covered bridges include members contacting abutments, members near the ends of bridges...

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...

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 ...

Browsing Patterns of White-Tailed Deer Following Increased Timber Harvest and a Decline in Population Density

Directory of Open Access Journals (Sweden)

Shawn M. Crimmins

2010-01-01

Full Text Available We examined browsing patterns of white-tailed deer (Odocoileus virginianus on a site in the central Appalachians that experienced a substantial (>50% reduction in deer population density and an increase in the amount of timber harvest since 2001. We sampled woody browse in and immediately adjacent to 12 clearcuts ranging in age from 0–5 years postharvest in summer 2007. Clearcut-interior areas had higher woody browse abundance and browsing rates than clearcut-edge or mature forest areas. Woody browse abundance was slightly higher within individual clearcuts than in 2001 at higher population densities and lower timber harvest rates. Overall browsing rates declined from approximately 17% in 2001 to less than 5% during our study, suggesting that the combination of deer population control, and increasing the amount of timber harvest across the landscape can reduce herbivory to levels that may not impede growth and survival of forest vegetation.

Influence of material deterioration on strength properties of hydraulic timber structures

NARCIS (Netherlands)

Gard, W.F.; Van de Kuilen, J.W.G.; Cabrera de Diego, M.

2014-01-01

Hydraulic timber structures such as mooring poles, fenders, lock gates and jetties are widely-used in inner and sea harbours all over the world. In general these structures give satisfactory performance with regard to the technical requirements. Because of the harsh exposure conditions such as

Non-timber forest products of the North-West District of Guyana

NARCIS (Netherlands)

Andel, T.R. van

2000-01-01

This thesis describes the use of non-timber forest products (NTFPs) by indigenous peoples of northwest Guyana. Part I contains a general analysis of NTFP harvesting in northwest Guyana Part II is an illustrated field guide of the useful plants encountered. Chapter 1: introduction Chapter

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.

Timber product implications of a program of mechanical fuel treatments applied on public timberland in the Western United States

Science.gov (United States)

Barbour R. James.; Xiaoping Zhou; Jeffrey P. Prestemon

2008-01-01

This study reports the results from a 5 year simulation of forest thinning intended to reduce fire hazard on publicly managed lands in the western United States. A state simulation model of interrelated timber markets was used to evaluate the timber product outputs. Approximately 84 million acres (34 million hectares), or 66% of total timberland in the western United...

A Comparative Cradle-to-Gate Life Cycle Assessment of Mid-Rise Office Building Construction Alternatives: Laminated Timber or Reinforced Concrete

Directory of Open Access Journals (Sweden)

Raymond J. Cole

2012-07-01

Full Text Available The objective of this project was to quantify and compare the environmental impacts associated with alternative designs for a typical North American mid-rise office building. Two scenarios were considered; a traditional cast-in-place, reinforced concrete frame and a laminated timber hybrid design, which utilized engineered wood products (cross-laminated timber (CLT and glulam. The boundary of the quantitative analysis was cradle-to-construction site gate and encompassed the structural support system and the building enclosure. Floor plans, elevations, material quantities, and structural loads associated with a five-storey concrete-framed building design were obtained from issued-for-construction drawings. A functionally equivalent, laminated timber hybrid design was conceived, based on Canadian Building Code requirements. Design values for locally produced CLT panels were established from in-house material testing. Primary data collected from a pilot-scale manufacturing facility was used to develop the life cycle inventory for CLT, whereas secondary sources were referenced for other construction materials. The TRACI characterization methodology was employed to translate inventory flows into impact indicators. The results indicated that the laminated timber building design offered a lower environmental impact in 10 of 11 assessment categories. The cradle-to-gate process energy was found to be nearly identical in both design scenarios (3.5 GJ/m2, whereas the cumulative embodied energy (feedstock plus process of construction materials was estimated to be 8.2 and 4.6 GJ/m2 for the timber and concrete designs, respectively; which indicated an increased availability of readily accessible potential energy stored within the building materials of the timber alternative.

Timber-harvest clearcutting and nutrients in the Northeastern United States

Science.gov (United States)

K. G. Reinhart

1973-01-01

The effect of ecosystem disturbance on nutrients in the system has been receiving widespread attention. An appraisal of research results in the Northeast indicates that timber-harvest clearcutting has not increased nutrient levels sufficiently to reduce water quality below drinking water standards. Losses of nutrients from clearcuttings in New Hampshire over a 2-year...

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...

Archaeological investigation by geotomography: structure of the foundation of Yingxian timber pagoda

Science.gov (United States)

Feng, Rui; Yan, Wei-Zhang; Feng, Guo-Zheng; Tao, Yu-Lu; Zhou, Hai-Nan; Li, Xiao-Qin

1998-03-01

It is significant to take a non-destructive inspection, one of advanced techniques, for detecting the internal structure and the present status of ancient cultural relics. The results detected by geotomography in Yingxian timber pagoda, Shanxi Province, are presented in this paper. The embankment in the stepped foundation shows a three circular structure in horizontal: the circular platform core is hard, homogenous and unharmed, out of which there are some radial collapsed grooves. The middle circle with a thickness of 2 to 4 m is a compacted layer and its loading capacity decreases then. The outer protective layer has a larger porosity and a weak loading capacity. An abnormal body is found out in the core, which has a circular shape and a reverse high-absorption coefficient in the shallow part, but appears a long-band shape and a low-absorption coefficient in the deep part. It might be a disturbance caused by artificial activities: the shallow part is probably a channel filled with loosen soil and the deep part is a hidden cave. It is found that the foundation of the courtyard is homogenous and integrated. Two soft and weakened areas in the north are related to the long-term run-off and drainage of groundwater. The inclination of the timber pagoda to the northwest and northeast relates to several factors, such as the inherited subsidence of the northern foundation, the lower loading capacity of the outer stepped foundation, seismic activity and timber deformation.

The effect of changing ambient humidity on moisture condition in timber elements

DEFF Research Database (Denmark)

Hozjan, Tomaẑ; Turk, Goran; Srpĉiĉ, Stanislav

2012-01-01

a fully coupled transport model including a model for the influential sorption hysteresis of wood is used. The coupled model accounts for both vapor transport in pores and bound water transport in wood tissue. Moisture state history influences relationship between moisture state of wood and air humidity......This paper deals with the effect of the changing ambient humidity on moisture conditions in timber elements. The naturally varying humidity is possible to model as a relative combination of different harmonic cycles, with different periods and amplitudes. For the determination of the moisture field......, it must therefore be taken into account. In order to include history dependency, a hysteresis model is used here. Results from numerical calculations for timber specimen exposed to combined daily and annually cyclic variation of outside humidity are presented. Copyright © (2012) by WCTE 2012 Committee....

Socio-ecological costs of Amazon nut and timber production at community household forests in the Bolivian Amazon.

Science.gov (United States)

Soriano, Marlene; Mohren, Frits; Ascarrunz, Nataly; Dressler, Wolfram; Peña-Claros, Marielos

2017-01-01

The Bolivian Amazon holds a complex configuration of people and forested landscapes in which communities hold secure tenure rights over a rich ecosystem offering a range of livelihood income opportunities. A large share of this income is derived from Amazon nut (Bertholletia excelsa). Many communities also have long-standing experience with community timber management plans. However, livelihood needs and desires for better living conditions may continue to place these resources under considerable stress as income needs and opportunities intensify and diversify. We aim to identify the socioeconomic and biophysical factors determining the income from forests, husbandry, off-farm and two keystone forest products (i.e., Amazon nut and timber) in the Bolivian Amazon region. We used structural equation modelling tools to account for the complex inter-relationships between socioeconomic and biophysical factors in predicting each source of income. The potential exists to increase incomes from existing livelihood activities in ways that reduce dependency upon forest resources. For example, changes in off-farm income sources can act to increase or decrease forest incomes. Market accessibility, social, financial, and natural and physical assets determined the amount of income community households could derive from Amazon nut and timber. Factors related to community households' local ecological knowledge, such as the number of non-timber forest products harvested and the number of management practices applied to enhance Amazon nut production, defined the amount of income these households could derive from Amazon nut and timber, respectively. The (inter) relationships found among socioeconomic and biophysical factors over income shed light on ways to improve forest-dependent livelihoods in the Bolivian Amazon. We believe that our analysis could be applicable to other contexts throughout the tropics as well.

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...

31 CFR 593.412 - Release of any round log or timber product originating in Liberia from a bonded warehouse or...

Science.gov (United States)

2010-07-01

... product originating in Liberia from a bonded warehouse or foreign trade zone. 593.412 Section 593.412... Interpretations § 593.412 Release of any round log or timber product originating in Liberia from a bonded... from a bonded warehouse or foreign trade zone of any round log or timber product originating in Liberia...

Analysis of the strength and stiffness of timber beams reinforced with carbon fiber and glass fiber

Directory of Open Access Journals (Sweden)

Juliano Fiorelli

2003-06-01

Full Text Available An experimental analysis of pinewood beams (Pinus caribea var hondurensis reinforced with glass and/or carbon fibers is discussed. The theoretical model employed to calculate the beam's bending strength takes into account the timber's ultimate limit states of tensile strength and failure by compression, considering a model of fragile elastic tension and plastic elastic compression. The validity of the theoretical model is confirmed by a comparison of the theoretical and experimental results, while the efficiency of the fiber reinforcement is corroborated by the increased strength and stiffness of the reinforced timber beams.

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.

A combined loading system integrated with portable winch and polyethylene chutes for loading of timber products

Directory of Open Access Journals (Sweden)

H. Hulusi Acar

2016-01-01

Full Text Available Truck loading operation is an important task during timber production operations in forestry. In Turkey, approximately 50 million timbers/logs are being produced per year, and then they are loaded into the logging trucks. The timber/logs are transported over the forest roads with an average of one million roundtrips. However, the traditional loading methods using manpower are mostly performed while some part is done by using loading machines which can be very costly and risky. This study aims developing a combined loading system in which heavy logs are loaded into logging trucks by pulling them by a log-line powered by a portable crane within the chute system. The slope of the log-line from ground to logging truck varied between 1% and 25%. Within the each work cycle of loading operation, only one log was loaded by pulling with portable crane. The average loading time was found as 161.8 seconds per cycle, in which 67% of the time was spent on pulling the log into the logging truck. The results indicated that the average pulling speed with crane power was 840.4 m/hr and productivity was calculated as 4.94 m3/hr. The result on system speed and productivity indicated close relations with results from previous studies. The hydraulic grapple loader or cranes are widely used and common loading machines, but they cannot be efficiently used in forestry operations, especially ones having a low timber productivity rate or having low economic value timber. In these conditions, loading methods that are cost efficient and do not require higher production rate should be employed. Therefore, a combined loading system introduced in this study can be a feasible solution for loading operations in those cases. Furthermore, it is believed that this loading system integrated with a portable crane can be cost efficient and time saving solution, as well as ergonomic and safe method in the field.

Evaluating carbon storage, timber harvest, and habitat possibilities for a Western Cascades (USA) forest landscape.

Science.gov (United States)

Kline, Jeffrey D; Harmon, Mark E; Spies, Thomas A; Morzillo, Anita T; Pabst, Robert J; McComb, Brenda C; Schnekenburger, Frank; Olsen, Keith A; Csuti, Blair; Vogeler, Jody C

2016-10-01

Forest policymakers and managers have long sought ways to evaluate the capability of forest landscapes to jointly produce timber, habitat, and other ecosystem services in response to forest management. Currently, carbon is of particular interest as policies for increasing carbon storage on federal lands are being proposed. However, a challenge in joint production analysis of forest management is adequately representing ecological conditions and processes that influence joint production relationships. We used simulation models of vegetation structure, forest sector carbon, and potential wildlife habitat to characterize landscape-level joint production possibilities for carbon storage, timber harvest, and habitat for seven wildlife species across a range of forest management regimes. We sought to (1) characterize the general relationships of production possibilities for combinations of carbon storage, timber, and habitat, and (2) identify management variables that most influence joint production relationships. Our 160 000-ha study landscape featured environmental conditions typical of forests in the Western Cascade Mountains of Oregon (USA). Our results indicate that managing forests for carbon storage involves trade-offs among timber harvest and habitat for focal wildlife species, depending on the disturbance interval and utilization intensity followed. Joint production possibilities for wildlife species varied in shape, ranging from competitive to complementary to compound, reflecting niche breadth and habitat component needs of species examined. Managing Pacific Northwest forests to store forest sector carbon can be roughly complementary with habitat for Northern Spotted Owl, Olive-sided Flycatcher, and red tree vole. However, managing forests to increase carbon storage potentially can be competitive with timber production and habitat for Pacific marten, Pileated Woodpecker, and Western Bluebird, depending on the disturbance interval and harvest intensity chosen

Simplified Analytical Model of a Covered Burr-Arch-Truss Timber Bridge

Science.gov (United States)

F. Fanous; D. Rammer; T. Wipf

2013-01-01

Due to the importance of historical timber covered bridges throughout history, their preservation is necessary. However, conducting an accurate structural evaluation of these types of bridges has always caused difficulties to bridge engineers. This paper summarizes an investigation that was sponsored by the Federal Highway Administration and the USDA Forest Products...

Estimating and validating ground-based timber harvesting production through computer simulation

Science.gov (United States)

Jingxin Wang; Chris B. LeDoux

2003-01-01

Estimating ground-based timber harvesting systems production with an object oriented methodology was investigated. The estimation model developed generates stands of trees, simulates chain saw, drive-to-tree feller-buncher, swing-to-tree single-grip harvester felling, and grapple skidder and forwarder extraction activities, and analyzes costs and productivity. It also...

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...

A computer-based time study system for timber harvesting operations

Science.gov (United States)

Jingxin Wang; Joe McNeel; John Baumgras

2003-01-01

A computer-based time study system was developed for timber harvesting operations. Object-oriented techniques were used to model and design the system. The front-end of the time study system resides on the MS Windows CE and the back-end is supported by MS Access. The system consists of three major components: a handheld system, data transfer interface, and data storage...

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...

Greek timber industries and wood product markets over the last century: development constraints and future directions

Directory of Open Access Journals (Sweden)

Panagiotis P. Koulelis

2011-01-01

Full Text Available This paper examines the Greek forestry sector after 1930. According to the past literature, the sector was entirely degraded and reliable data are not available. The study analyses critical historical data about timber sector and timber companies; the main objective is the specification of the factors that kept the Greek forest sector underdevelopment. The factors and the development constraints, including the indigenous characteristics of the Greek forests, the inhibitory policy for timber production investments, especially in the state industries, lack of market research, unorthodox procedures for sale of the wood, bad quality and high cost of production and periods of general economic recession are analyzed farther. Conclusively, the need for producing official forest maps, forest data recording, rapid adaptation to EU specifications, investments, deep changes in to the managership of the state industries, permanent and specialized personnel and promotion of national programs for the development of the small-scale wood elaboration and wood selling industrial units are some of the solutions for the above problems that could be suggested.

Greek timber industries and wood product markets over the last century: development constraints and future directions

Directory of Open Access Journals (Sweden)

Panagiotis P. Koulelis

2013-12-01

Full Text Available This paper examines the Greek forestry sector after 1930. According to the past literature, the sector was entirely degraded and reliable data are not available. The study analyses critical historical data about timber sector and timber companies; the main objective is the specification of the factors that kept the Greek forest sector underdevelopment. The factors and the development constraints, including the indigenous characteristics of the Greek forests, the inhibitory policy for timber production investments, especially in the state industries, lack of market research, unorthodox procedures for sale of the wood, bad quality and high cost of production and periods of general economic recession are analyzed farther. Conclusively, the need for producing official forest maps, forest data recording, rapid adaptation to EU specifications, investments, deep changes in to the managership of the state industries, permanent and specialized personnel and promotion of national programs for the development of the small-scale wood elaboration and wood selling industrial units are some of the solutions for the above problems that could be suggested.

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

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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.

Mechanical properties of structural maritime pine sawn timber from Galicia (Pinus pinaster Ait. ssp. atlantica)

Energy Technology Data Exchange (ETDEWEB)

Carballo, J.; Hermoso, E.; Fernandez-Golfin, J. I.

2009-07-01

The use of maritime pine sawn timber in structural applications requires knowledge of its mechanical properties. Standards have changed, however, since the last research on this timber was performed. In the present study, 491 beams of maritime pine from Gaelic, of structural-use size but different cross-section, were tested according to these modified standards. Each beam was visually graded according to standard UNE 56.544 and subjected to a four point bending test. The strength classes assigned by the visual grades awarded suggest this material to have greater structural capacity than that currently assumed. The relationships between the modulus of elasticity, strength and density were also examined. (Author) 25 refs.

Lateral Load-Resisting System Using Mass Timber Panel for High-Rise Buildings

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Zhiyong Chen

2017-07-01

Full Text Available As global interest in using engineered wood products in tall buildings intensifies due to the “green” credential of wood, it is expected that more tall wood buildings will be designed and constructed in the coming years. This, however, brings new challenges to the designers. One of the major challenges is how to design lateral load-resisting systems (LLRSs with sufficient stiffness, strength, and ductility to resist strong wind and earthquakes. In this study, an LLRS using mass timber panel on a stiff podium was developed for high-rise buildings in accordance with capacity-based design principle. The LLRS comprises eight shear walls with a core in the center of the building, which was constructed with structural composite lumber and connected with dowel-type connections and wood–steel composite system. The main energy dissipating mechanism of the LLRS was detailed to be located at the panel-to-panel interface. This LLRS was implemented in the design of a hypothetical 20-storey building. A finite element (FE model of the building was developed using general-purpose FE software, ABAQUS. The wind-induced and seismic response of the building model was investigated by performing linear static and non-linear dynamic analyses. The analysis results showed that the proposed LLRS using mass timber was suitable for high-rise buildings. This study provided a valuable insight into the structural performance of LLRS constructed with mass timber panels as a viable option to steel and concrete for high-rise buildings.

Beliefs about the Potential Impacts of Exploiting Non-Timber Forest Products Predict Voluntary Participation in Monitoring

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Dantas Brites, Alice; Morsello, Carla

2017-06-01

Harvesting and trading non-timber forest products is advocated as a win-win strategy for conservation and development, yet it can produce negative ecological and socioeconomic impacts. Hence, monitoring exploitation outcomes is essential, and participatory monitoring has been suggested to be the most suitable approach. Among possible approaches, participatory monitoring is preferred because it is likely to increase people's awareness and beliefs regarding impacts or potential impacts, thus inducing behavioral changes, although the evidence in this regard is contradictory. We therefore evaluated whether people's beliefs about the potential ecological and socioeconomic impacts of non-timber forest product exploitation increased their likelihood of volunteering to monitor. We studied a community of forest inhabitants in the Brazilian Amazon who harvested and traded a commercially important non-timber forest product. Two methods of data gathering were employed: (i) a survey of 166 adults (51 households) to evaluate people's beliefs and their stated intention to engage in four different monitoring tasks and (ii) four pilot monitoring tasks to evaluate who actually participated. Based on mixed-effects regressions, the results indicated that beliefs regarding both types of impacts could predict participation in certain tasks, although gender, age and schooling were occasionally stronger predictors. On average, people had stronger beliefs about potential socioeconomic impacts than about potential ecological impacts, with the former also predicting participation in ecological data gathering. This finding reinforces the importance of monitoring both types of impacts to help achieve the win-win outcomes originally proposed by non-timber forest product trade initiatives.

A NOTE ON METHODS FOR THE ESTIMATION OF THE AIRBORNE SOUND INSULATION OF TIMBER FRAME STRUCTURES

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Jan Šlechta

2016-04-01

Full Text Available Acoustic behavior of structures with wooden elements is nowadays of great interest. At the same time, the estimation of the airborne sound insulation of timber frame structures is a complex procedure which includes the prediction of several resonances and the analysis of a significant decrease of the transmission loss in the low frequency range. Three case studies are presented in the paper. The emphasis is put on the transmission loss in 1/3 octave frequency bands of double leaf structures with gypsum panels, wood studs and a well-damped cavity. Methods of Sharp and Davy are used for the transmission loss prediction. Particular issues are discussed for an asymmetrically sheathed timber frame structure, wood studs with resilient channels and staggered studs. The paper also presents that the weighted sound reduction index is not sufficient quantity for characterizing the airborne sound insulation of timber frame structures. Various methods are employed for the calculation of the transmission loss of a traditional structure on a silicate base. Characteristic differences between a silicate based structure and a timber frame structure are highlighted. The usage of the spectrum adaptation terms is encouraged. The paper intends to be helpful in the field of the transmission loss estimation of double leaf structures with wood studs. Since the acoustic behavior of double leaf structures with wood studs is certainly a complex phenomenon, there is a further need for an improvement of methods for the transmission loss estimation and single number quantities for the evaluation of the sound insulation.

Mechanical performance and contact zone of timber joint with oblique faces

Czech Academy of Sciences Publication Activity Database

Kunecký, Jiří; Sebera, V.; Tippner, J.; Hasníková, Hana; Kloiber, Michal; Arciszewska-Kędzior, Anna; Milch, J.

2015-01-01

Roč. 63, č. 4 (2015), s. 1153-1159 ISSN 1211-8516 R&D Projects: GA MK(CZ) DF12P01OVV004 Keywords : bending * contact zone * digital image correlation * dowel * non-destructive test ing * timber joint Subject RIV: AL - Art, Architecture, Cultural Heritage http://dx.doi.org/10.11118/actaun201563041153

Timber resource statistics for nonnational forest land in western Washington, 2001.

Science.gov (United States)

Andrew N. Gray; Charles F. Veneklase; Robert D. Rhoads

2005-01-01

This report is a summary of timber resource statistics for an inventory of the 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. The inventory in 2000 sampled all private and public lands except those...

Who, what, and why: the products, their use, and issues about management of non-timber forest products in the United States

Science.gov (United States)

Susan J. Alexander

2001-01-01

Non-timber forest products in the United States include floral greens, Christmas ornamentals, wild edibles, medicinals, crafts, and transplants. Non-timber forest products are important to many people for many reasons. People harvest products from forests for personal use, cultural practices, and sale. The tremendous variety of species harvested for the many markets...

Chapter 8: Fire Performance of Cross-Laminated Timber Assemblies (2012 US Edition)

Science.gov (United States)

Christian Dagenais; Robert H. White; Kuma Sumathipala

2012-01-01

Cross-laminated timber (CLT) is a promising wood-based structural component and has potential to provide cost-effective building solutions for residential, commercial and institutional buildings as well as large industrial facilities. Market acceptance of CLT requires that it meets the applicable building code requirements.

Heavy laminated timber frame with rigid three-dimensional beam-to-column connections

Czech Academy of Sciences Publication Activity Database

Kasal, B.; Guindos, P.; Polocoser, T.; Heiduschke, A.; Urushadze, Shota; Pospíšil, Stanislav

2014-01-01

Roč. 28, č. 6 (2014) ISSN 0887-3828 Institutional support: RVO:68378297 Keywords : seismic performance * timber frame * synthetic seismic excitation Subject RIV: JM - Building Engineering Impact factor: 0.631, year: 2014 http://ascelibrary.org/doi/abs/10.1061/(ASCE)CF.1943-5509.0000594

Oregon’s forest products industry and timber harvest, 2008: industry trends and impacts of the Great Recession through 2010

Science.gov (United States)

Charles B. Gale; Charles E. Keegan; Erik C. Berg; Jean Daniels; Glenn A. Christensen; Colin B. Sorenson; Todd A. Morgan; Paul. Polzin

2012-01-01

This report traces the flow of Oregon’s 2008 timber harvest through the primary timber processing industry and provides a description of the structure, operation, and condition of Oregon’s forest products industry as a whole. It is the second in a series of reports that update the status of the industry every 5 years. Based on a census conducted in 2009 and 2010, we...

Tree-Rings, Timbers and Trees: A dendrochronological survey of the 14th-century cog, Doel 1

DEFF Research Database (Denmark)

Haneca, Kristof; Daly, Aoife

2014-01-01

In 2000, the remains of a cog, Doel 1, were found in Doel, Belgium. Wood species identification of all ship timbers and smaller elements was performed. European oak was the dominant species, followed by alder that was used for the fairings. In total 150 ring-width series were recorded. The constr......In 2000, the remains of a cog, Doel 1, were found in Doel, Belgium. Wood species identification of all ship timbers and smaller elements was performed. European oak was the dominant species, followed by alder that was used for the fairings. In total 150 ring-width series were recorded...

Global modelling to predict timber production and prices: the GFPM approach

Science.gov (United States)

Joseph Buongiorno

2014-01-01

Timber production and prices are determined by the global demand for forest products, and the capability of producers from many countries to grow and harvest trees, transform them into products and export. The Global Forest Products Model (GFPM) simulates how this global demand and supply of multiple products among many countries determines prices and attendant...

Dynamic characteristics of timber bridges as a measure of structural integrity

Science.gov (United States)

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

2003-01-01

Bridges require periodic inspections to ensure the safety of those using the structure. A myriad of techniques have been developed in order to quickly and accurately determine a structure's health. Unfortunately, timber structures are still, in most cases, subjectively evaluated. Decay is one of the most common damage mechanisms in these structures, and often...

Timber resource statistics for the north interior 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 North Interior Resource Area of California, which includes Lassen, Modoc, Shasta, Siskiyou, and Trinity Counties. Data were collected as part of a statewide multiresource inventory. The inventory sampled private and public lands except reserved areas and National Forests. The National Forest System provided...

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.

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...

REDD+ and international leakage via food and timber markets: a CGE analysis

NARCIS (Netherlands)

Kuik, O.J.

2014-01-01

This paper studies the effect of international trade in food and timber on land use and potential carbon leakage in the context of actions to reduce emissions from deforestation and forest degradation (REDD+). First a simple analytical model of international leakage is presented that focuses on

Optimizing continuous cover management of boreal forest when timber prices and tree growth are stochastic

Directory of Open Access Journals (Sweden)

Timo Pukkala

2015-03-01

Full Text Available Background Decisions on forest management are made under risk and uncertainty because the stand development cannot be predicted exactly and future timber prices are unknown. Deterministic calculations may lead to biased advice on optimal forest management. The study optimized continuous cover management of boreal forest in a situation where tree growth, regeneration, and timber prices include uncertainty. Methods Both anticipatory and adaptive optimization approaches were used. The adaptive approach optimized the reservation price function instead of fixed cutting years. The future prices of different timber assortments were described by cross-correlated auto-regressive models. The high variation around ingrowth model was simulated using a model that describes the cross- and autocorrelations of the regeneration results of different species and years. Tree growth was predicted with individual tree models, the predictions of which were adjusted on the basis of a climate-induced growth trend, which was stochastic. Residuals of the deterministic diameter growth model were also simulated. They consisted of random tree factors and cross- and autocorrelated temporal terms. Results Of the analyzed factors, timber price caused most uncertainty in the calculation of the net present value of a certain management schedule. Ingrowth and climate trend were less significant sources of risk and uncertainty than tree growth. Stochastic anticipatory optimization led to more diverse post-cutting stand structures than obtained in deterministic optimization. Cutting interval was shorter when risk and uncertainty were included in the analyses. Conclusions Adaptive optimization and management led to 6%–14% higher net present values than obtained in management that was based on anticipatory optimization. Increasing risk aversion of the forest landowner led to earlier cuttings in a mature stand. The effect of risk attitude on optimization results was small.

Integrating Forage, Wildlife, Water, and Fish Projections with Timber Projections at the Regional Level: A Case Study in Southern United States

Science.gov (United States)

Linda A. Joyce; Curtis H. Flather; Patricia A. Flebbe; Thomas W. Hoekstra; Stan J. Ursic

1990-01-01

The impact of timber management and land-use change on forage production, turkey and deer abundance, red-cockaded woodpecker colonies, water yield, and trout abundance was projected as part of a policy study focusing on the southern United States. The multiresource modeling framework used in this study linked extant timber management and land-area policy models with...

Testing and investigation of metal-coated concrete timbering conditions of L'vovsko-Volynskiy coal basin

Energy Technology Data Exchange (ETDEWEB)

Parchevskiy, L Ya; Kozhushko, Yu M; Lebedeva, G V; Turchanin, G I

1981-01-01

A combined metal-coated concrete timber has been tested in ''Velikomostovskaya'' well No. 10 at the Ukrzapadugol' production association: while advancing an AP arch made of SVP-27 was put in place and guyed with metal mesh filled with rubble; a sprayed concrete mixture of various compositions was then applied at distances of 30-50 meters. The increased monolithic strength of the sprayed concrete was determined, as well as the degree of penetration of the sprayed mixture and its strength. The basic parameters of the timbering provided sufficient stability over a period of four years of testing. An analysis is given for the tested reinforcement which confirms that its bearing capacity is sufficient.