Influence of saw chain type and wood species on the kickback angle of a chainsaw

Wood processing operations, in particular debarking, can pose a significant hazard for the chainsaw operator when performed without due caution. The most common hazards with potentially fatal consequences include kickback which occurs when the chainsaw’s guide bar is violently thrown backwards towards the operator. The aim of this study was to determine the influence of wood species and different saw chain brands on the kickback angle of a chainsaw. The kickback angle of a combustion chainsaw was analyzed in a self-designed test stand with the use of a digital level gauge accurate to 0.1°. Four differently priced saw chain brands, including two standard chains and two chains with anti-kickback features, were evaluated. Kickback was analyzed on five wood species (pine, spruce, birch, alder and oak) at three engine speeds (50%, 75% and 100% of maximum rotational speed). Kickback was significantly determined by wood species and saw chain type, and it was less influenced by the rotational speed of the chainsaw engine. The average kickback angle was largest in alder and smallest in spruce. The analyzed parameter was not always reduced by saw chains with anti-kickback features. In some cases, low-priced saw chains with anti-kickback features offer less protection than more expensive standard chains. Chainsaw buyers should decide whether it is worthwhile to compromise on safety in exchange for a lower price.

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Comprehensive evaluation of the industrial processing effects on the fiber properties of the pulps from wood residues

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2020-0065 ◽

2020 ◽

Vol 35 (4) ◽

pp. 631-640

Author(s):

Yuan Chen ◽

Kuizhong Shen ◽

Gaiyun Li

Keyword(s):

Thermal Stability ◽

Wood Species ◽

Large Scale ◽

Fiber Quality ◽

Paper Industry ◽

Negative Influence ◽

Industrial Applications ◽

Hydroxyl Groups ◽

Wood Processing ◽

Fiber Separation

AbstractWood processing residue, as an essential forest resource, is underestimated in the industrial applications. With the development of pulping technology, fiber quality and cost control have become the important prospects. It is very crucial to investigate the influencing factors of pulping, designed to reveal the relationship between fiber separation and physical performances. In this study, a range of effect factors of large-scale pulping process, including wood species, pretreatment, mechanical conditions, and post-bleaching treatment, were comprehensively investigated. The results illustrated that the industrial pulping process affected the dimensions of the fibers, their surface morphology, chemical structure, and thermal stability. The separated positions of the fibers were determined collectively by the mechanical temperature, time, and wood species. In addition, mild bleaching could effectively increase the crystallinity index, accessibility of the hydroxyl groups, and water retention values. However, it exerted a negative influence on the thermal stability. Further, chemical-assisted-refinement can replace higher temperature and prolonged ones to obtain pulp fibers with high quality while consuming less energy. Improved knowledge of how the industrial affects the fiber separation of a wood matrix and pulp quality is required as a basis for the development of the pulp and paper industry.

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WOOD PROCESSING BY-PRODUCTS TREATED WITH THE LIGNIN-BASED CONDITIONER AS MULCH FOR SOIL PROTECTION

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2015.1018267 ◽

2015 ◽

Vol 23 (4) ◽

pp. 279-287 ◽

Cited By ~ 2

Author(s):

Galia SHULGA ◽

Talrits BETKERS ◽

Sanita VITOLINA ◽

Brigita NEIBERTE ◽

Anrijs VEROVKINS ◽

...

Keyword(s):

Sandy Soil ◽

Wood Species ◽

Negative Impact ◽

Application Rate ◽

Soil Protection ◽

Hydrolysis Lignin ◽

Simultaneous Application ◽

Soil Conditioner ◽

Wood Processing ◽

By Products

Wood processing by-products such as bark of different wood species and hydrolysis lignin were applied as soil mulch. The lignin-based soil conditioner (LSC) representing a lignin-based polyelectrolyte complex with the different composition (a lignin/polymer mass ratio) was obtained under laboratory conditions and was intended to protect sandy soil from erosion by simultaneous application of a soil conditioner as an adhesive, mulch and plant seeds by hydroseeding. The study revealed the pronounced dependence of the properties of the treated wood-originated mulch on the wood species as well as on the composition, the applied concentration and the application rate of LSC. A comparison of the obtained results showed that the treated hydrolysis lignin was characterised by higher compressive strength, higher water resistance and lower moisture losses from sandy soil for a given LSC composition and application rate than the bark-based mulch. The conditioner concentrations don't have negative impact on the germination of seeds plants of the coastal dune zone.

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Study and Evaluation on Physical and Mechanical Properties of 40 Kinds of Wood Species in Zhejiang Province (China)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.657 ◽

2014 ◽

Vol 962-965 ◽

pp. 657-662

Author(s):

Man Ping Xu ◽

Fei Yan Guo ◽

Kan Kan Zhou ◽

Wei Ming Yang

Keyword(s):

Mechanical Properties ◽

Wood Species ◽

Bending Strength ◽

Comprehensive Evaluation ◽

Physical And Mechanical Properties ◽

Zhejiang Province ◽

Modulus Of Rupture ◽

Processing Application ◽

Wood Processing ◽

Analysis Methods

Physical and mechanical properties of 40 kinds of typical wood species in Zhejiang province were studied in this experiment. Density, shrinkage rate, modulus of rupture,bending strength, compression strength, shear strength and hardness were measured and wood species were classified and evaluated by clustering analysis mehtod (CA) combined with membership function (MF) comprehensive evaluation according to these properties. The results showed that the two analysis methods achieved the similar results when screening first class wood which can be conclued that among the 40 kinds of species Quercus fabri, Dalbergia hupeana Cyclobalanopsis glauca, Lithocarpus harlandii and Lagerstroemia indica were the excellent quality. In the mean while the two analysis methods got the similar conclusion that wood properties of Pterocarya stenoptera were the worest as well. In addation, Camptotheca acuminata and Alniphyllum fortune according to CA and Ilex rotunda, and Cyclocarya paliurus according to MF were also the worest qulaity. The study provided powerful references for wood processing, application and directional cultivation of indigenous tree species in Zhejiang.

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PROPOSITION OF NEW SINGLE TEST CYCLE OF INTERNAL COMBUSTION ENGINE DURING STAND RELIABILITY TESTS

Scientific Journal of the Military University of Land Forces ◽

10.5604/01.3001.0002.2860 ◽

2011 ◽

Vol 159 (1) ◽

pp. 50-57

Author(s):

Paweł DROŹDZIEL ◽

Paweł KORDOS

Keyword(s):

Rotational Speed ◽

Internal Combustion Engines ◽

Internal Combustion ◽

Reliability Evaluation ◽

Average Frequency ◽

Test Stand ◽

Test Cycle ◽

Engine Operation ◽

Start Ups ◽

Engine Start

A test-stand reliability evaluation of automotive internal combustion engines is carried out so as to determine the selected reliability parameters, such as an average occurrence of defects, an average frequency of part exchange, an average frequency of engine regulation or the wear of selected engine components. The values of these indicators make it possible to estimate the durability of components used as well as of the whole structure of the engine. During reliability test-stand research, the engine is run according to multiple repeated cycles of operation. The conditions of engine operation during reliability tests can be characterized by time invariability and extreme values of rotational speed and torque. In this article the authors prove that the conditions of real automotive engine operation are much more diversified (city driving) with a high share of partial loads (intercity driving). Another significant difference in test-stand reliability evaluation and real operation is the frequency of engine start-ups. In real conditions engine start-ups are far more frequent. The authors propose a new test cycle, which will enable reproducing the real engine operation conditions in stand tests. Characteristic features of this test include more frequent starts and distinguishing between the two kinds of variability in conditions of operation: city and intercity driving, with “lighter” values of rotational speed and torque.

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Principles of obtaining light permeable conglomerate materials based on wood filler

Journal of Physics Conference Series ◽

10.1088/1742-6596/2131/4/042033 ◽

2021 ◽

Vol 2131 (4) ◽

pp. 042033

Author(s):

A Pichugin ◽

V Khritankov ◽

S Tkachenko

Keyword(s):

Technological Process ◽

Wood Species ◽

Economic Costs ◽

New Materials ◽

Processing Waste ◽

Wood Processing ◽

Structural Functions ◽

The World ◽

Translucent Material ◽

Decorative Design

Abstract Recently, the world has seen a demand for transparent or translucent concrete, capable of performing both, structural functions and decorative - design tasks. Such concrete use opens up new opportunities for the creative searches of designers, allows inclusion of new materials in those elements of decorating the internal and external of buildings, structures, large and small architectural forms. The research results on obtaining a new translucent material in the form of wood concrete (arbolite), which makes it possible to introduce previously unused wood processing waste of low-value wood species - birch and aspen into the technological process are presented in the article. The primary results open up new possibilities for light-conducting concretes at significantly low economic costs of their production. The results allows us to conclude about the complexity and ambiguity of wood bleaching processes and the need to strictly follow optimal formulations, modes and compositions at all stages of production.

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The Immunological Characterization of Human Antibodies to Factor VIII Isolated by Immuno-Affinity Chromatography

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650129 ◽

1981 ◽

Vol 45 (01) ◽

pp. 060-064 ◽

Cited By ~ 10

Author(s):

M L Kavanagh ◽

C N Wood ◽

J F Davidson

Keyword(s):

Factor Viii ◽

Affinity Chromatography ◽

Gel Filtration ◽

Immunological Characterization ◽

Human Antibodies ◽

Heavy Chains ◽

Light Chain Type ◽

Antibody Preparations ◽

Chain Type

SummaryNine human antibodies to factor VIII were isolated from haemophilic plasmas by affinity chromatography and gel filtration and six were subsequently subjected to immunological characterization. Three partially purified preparations were similarly characterized. Eight of the antibodies were characterized as being exclusively IgG and one preparation was found to contain IgM. Seven of the antibodies contained only a single light chain type, four being of type lambda and three of type kappa. Two antibody preparations contained both kappa and lambda light chains. In four of the preparations, only a single heavy chain sub-class could be demonstrated, three of IgG3 and one of IgG4. Of the remainder, three were a mixture of IgG3 and IgG4 sub-classes and one contained both IgG2 and IgG4. IgG sub-classification could not be achieved with the IgM-containing preparation. These results demonstrate a restricted heterogeneity of light and heavy chains in human antibodies to factor VIII.

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Sialic Acid Dependent Polypeptide Chain Heterogeneity of Human Fibrinogen Demonstrated by Two-Dimensional Electrophoresis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657116 ◽

1982 ◽

Vol 47 (01) ◽

pp. 019-021 ◽

Cited By ~ 13

Author(s):

Cemal Kuyas ◽

André Haeberli ◽

P Werner Straub

Keyword(s):

Sialic Acid ◽

Polypeptide Chain ◽

Two Dimensional ◽

Charge Heterogeneity ◽

Human Fibrinogen ◽

Two Dimensional Electrophoresis ◽

Isoelectric Points ◽

Polypeptide Chains ◽

Dimensional Electrophoresis ◽

Chain Type

SummaryHuman fibrinogen was compared with asialofibrinogen by two-dimensional electrophoresis to evaluate the contribution of sialic acid to the heterogeneity of the γ- and Bβ-polypeptide chains.Reduced fibrinogen showed three major variants for both the γ- and Bβ-chains. In addition two minor γ-bands with a more acidic isoelectric point than the normal γ-chains were observed. Electrophoresis in the second dimension (SDS) suggests that these most acidic bands are γ-chain-variants with a higher molecular weight. In asialofibrinogen only two predominant variants with more alkaline isoelectric points were present in each chain type.It is concluded that enzymatic removal of sialic acid partially reduces the heterogeneity of the γ- and Bβ-polypeptide chains of human fibrinogen, but additional sources producing charge heterogeneity must be sought.

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Influence of anatomy on the adhesion performance of four wood species

Research Society and Development ◽

10.33448/rsd-v9i4.2727 ◽

2020 ◽

Vol 9 (4) ◽

pp. e31942727

Author(s):

João Gabriel Missia da Silva ◽

Pedro Nicó de Medeiros ◽

Denise Ransolin Soranso ◽

Vinicius Peixoto Tinti ◽

José Tarcísio da Silva Oliveira ◽

...

Keyword(s):

Shear Strength ◽

Specific Gravity ◽

Wood Species ◽

Tectona Grandis ◽

Glue Line ◽

Anatomical Characteristics ◽

Ray Cells ◽

Adhesion Performance ◽

Adhesion Process

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.

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