scholarly journals INFLUENCE OF FOREST STAND DENSITY ON PINUS SYLVESTRIS ROUNDWOOD QUALITY IN EVEN-AGED MIXED SCOTS PINE STANDS IN MYRTILLOSA MEL. MESOTROPHIC SITE TYPE

Author(s):  
Ziedonis Miklašēvičs

Among different development directions for better forest utilization, the purposefully detailed assessment of wood quality as raw material, faciliating improved wood utilization in manufacturing of traditional roundwood products as well as brand new products, proves to be very perspective. Roundwood quality features substantially differ depending on forest stand geographic location, growing site conditions, tending of forest stands and other circumstances [2], [3], [11]. Therefore, the economical estimation of more important tree species in Latvia should not be based only on scientific conclusions made in other countries, so particular research is needed for this purpose. Pine (Pinus sylvestris) is the most widespread tree species in Latvia, therefore a research work provided the characteristic of round wood obtained from pine tree stem is an actual point from several aspects, as it is necessary;to create early prediction models of roundwood quality; to plan harvesting purposes;to create the data basis of economically more relevant domestic tree species;to provide the further development of roundwood quality assessment methods;to estimate the competitiveness of Latvia pine timber in the world marketThe main goal of study is to work out the quality characteristic of pine roundwood manufactured in final felling sites depending on timber formation damages- bark abrasion caused side drought.  

2019 ◽  
Vol 107 ◽  
pp. 124-130
Author(s):  
MAREK WIERUSZEWSKI ◽  
RADOSŁAW MIRSKI ◽  
ADRIAN TROCIŃSKI

Construction wood has to meet high requirements for loads capacity. Thanks to the selection and adequate classification of raw materials it is possible to decide how specific wood products can and should be used. The usage of solid wood for structural elements purposes has been precisely classified and specified in standardized requirements. Twelve classes of structural timber, ranging from C14 to C50, have been identified for softwood. Only part of Polish raw wood meets the standards of strength classes required in the building industry, as its strength corresponds to classes C24 and C30. A conclusion from research on the assortment structure of the raw materials in Poland was formed that it is particularly important to sort wood effectively according to its quality and intended use during processing. The material and strength efficiency is the main indicator of rational use of wood. The research resulted in setting the initial classification limits of selected round wood groups according to its strength. Properties determining the possibilities of obtaining a high quality product from the available raw wood material were taken into account in the research. Crucial factor was to select the proper research technology of determining dependencies between the applied research methodology and the defined wood quality, sorting class and strength class. The lower limit of availability of raw material with appropriate technical characteristics is determined during the selection of the research formula.


2001 ◽  
Vol 152 (5) ◽  
pp. 169-176 ◽  
Author(s):  
Monika Frehner

The article shows that knowledge of the site of a particular forest stand, together with research results and experience, can provide information that is important for the cultivation of mountain forests, including knowledge of the composition of the tree species and the structure and growth capacity of natural forest. Furthermore, certain sites can, thus, be characterized by factors that influence restocking, such as snow mould,lush ground vegetation or low temperature. The guidelines«minimale Pflegemassnahmen» – «Minimal tending of protection forests» (WASSER und FREHNER, 1996) are based on this principle. For individual sites, warnings about natural dangers such as rock fall or statements concerning nature conservation can be made (e.g., the occurrence of tree species, suitability as a biotope for Capercaille). In conclusion, two research projects on the relationship between site and natural dangers will be presented.


Author(s):  
Krzysztof Nadolny ◽  
Wojciech Kapłonek ◽  
Marzena Sutowska ◽  
Paweł Sutowski ◽  
Piotr Myśliński ◽  
...  

AbstractRaw pine wood processing and especially its mechanical processing constitute a significant share among technological operations leading to obtaining a finished product. Stable implementation of machining operations, ensuring long-term repeatable processing results depends on many factors, such as quality and invariability of raw material, technical condition of technological equipment, adopted parameters of work, qualifications and experience of operators, as well as preparation and properties of the machining tools used. It seems that the greatest potential in the search for opportunities to increase the efficiency of machining operations has the modification of machining tools used in it. This paper presents the results of research work aimed at determining how the life of cutting tools used in planing operations of wet pine wood is affected by the application of chromium aluminum nitride (AlCrN) coating to planar industrial planing knives in the process of physical vapour deposition. For this purpose operational tests were carried out under production conditions in a medium-sized wood processing company. The study compares the effective working time, rounding radius, the profile along the knife (size of worn edge displacement, wear area of the cutting edge), selected texture parameters of the planar industrial planing knife rake face and visual analyses of cutting edge condition of AlCrN-coated planar knives and unmodified ones. The obtained experimental results showed the possibility of increasing the life of AlCrN-coated knives up to 154% compared to the results obtained with uncoated ones. The proposed modification of the operational features of the knives does not involve any changes in the technological process of planing, does not require any interference with the machining station nor its parameters, therefore enabling rapid and easy implementation into industrial practice.


2001 ◽  
Vol 56 (1-2) ◽  
pp. 11-20 ◽  
Author(s):  
Harri Silvennoinen ◽  
Juha Alho ◽  
Osmo Kolehmainen ◽  
Timo Pukkala

2016 ◽  
Vol 16 (2) ◽  
pp. 43-50 ◽  
Author(s):  
Samander Ali Malik ◽  
Assad Farooq ◽  
Thomas Gereke ◽  
Chokri Cherif

Abstract The present research work was carried out to develop the prediction models for blended ring spun yarn evenness and tensile parameters using artificial neural networks (ANNs) and multiple linear regression (MLR). Polyester/cotton blend ratio, twist multiplier, back roller hardness and break draft ratio were used as input parameters to predict yarn evenness in terms of CVm% and yarn tensile properties in terms of tenacity and elongation. Feed forward neural networks with Bayesian regularisation support were successfully trained and tested using the available experimental data. The coefficients of determination of ANN and regression models indicate that there is a strong correlation between the measured and predicted yarn characteristics with an acceptable mean absolute error values. The comparative analysis of two modelling techniques shows that the ANNs perform better than the MLR models. The relative importance of input variables was determined using rank analysis through input saliency test on optimised ANN models and standardised coefficients of regression models. These models are suitable for yarn manufacturers and can be used within the investigated knowledge domain.


2015 ◽  
Vol 244 ◽  
pp. 121-129
Author(s):  
Marian Peciar ◽  
Roman Fekete ◽  
Peter Peciar

This article deals with the presentation of modern applications for processing powdered, primarily hazardous, waste to an agglomeration form appropriate for subsequent processing by classical methods, for example in the construction, automotive and consumer goods industries. The aim of the research work was to set appropriate operating conditions in order to appreciate currently non-processable wastes resulting from the intensive production of often extremely expensive materials. Technologies which enable returning powder waste back into the primary production cycle were developed and experimentally tested, thus saving raw material resources. When necessary for the fixing of fine airborne particles with a problematic compacting curve (hard to compress, repulsive due to the surface charge) extrusion processes using a patented technology enabling controlled modification of shear forces in the extrusion zone were successfully applied. A new type of axial extruder allows the elimination of the liquid phase and as a result prevents the clogging of the extrusion chamber. In the case of need for granulation of sensitive materials (for example pharmaceuticals not allowing the addition of any kind of agglomerating fluid or reacting strongly in the contact of the two phases), a process of compaction between rolls with different profiled surface was successfully applied. The developed high technologies and the resulting products thus represent a major contribution to environmental protection in the context of not only the work but also the communal environment.


2008 ◽  
Vol 84 (5) ◽  
pp. 694-703 ◽  
Author(s):  
Mahadev Sharma ◽  
John Parton ◽  
Murray Woods ◽  
Peter Newton ◽  
Margaret Penner ◽  
...  

The province of Ontario holds approximately 70.2 million hectares of forests: about 17% of Canada’s and 2% of the world’s forests. Approximately 21 million hectares are managed as commercial forests, with an annual harvest in the early part of the decade approaching 200 000 ha. Yield tables developed by Walter Plonski in the 1950s provide the basis for most wood supply calculations and growth projections in Ontario. However, due to changes in legislation, policy, and the planning process, they no longer fully meet the needs of resource managers. Furthermore, Plonski`s tables are not appropriate for the range of silvicultural options now practised in Ontario. In October 1999, the Canadian Ecology Centre- Forestry Research Partnership (CEC-FRP) was formed and initiated a series of projects that collectively aimed at characterizing, quantifying and ultimately increasing the economically available wood supply. Comprehensive, defensible, and reliable forecasts of forest growth and yield were identified as key knowledge gaps. The CEC-FRP, with support from the broader science community and forest industry, initiated several new research activities to address these needs, the results of which are outlined briefly in this paper. We describe new stand level models (e.g., benchmark yield curves, FVS Ontario, stand density management diagrams) that were developed using data collected from permanent sample plots and permanent growth plots established and remeasured during the past 5 decades. Similarly, we discuss new height–diameter equations developed for 8 major commercial tree species that specifically account for stand density. As well, we introduce a CEC-FRP-supported project aimed at developing new taper equations for plantation grown jack pine and black spruce trees established at varying densities. Furthermore, we provide an overview of various projects undertaken to explore measures of site productivity. Available growth intercept and site index equations are being evaluated and new equations are being developed for major commercial tree species as needed. We illustrate how these efforts are advancing Ontario’s growth and yield program and supporting the CEC-FRP in achieving its objective of increasing the supply of fibre by 10% in 10 years while maintaining forest sustainability. Key words: permanent sample plots (PSPs), permanent growth plots (PGPs), normal yield tables, sustainable forest management, NEBIE plot network, forest inventory, Forest Vegetation Simulator


2016 ◽  
Vol 12 (2) ◽  
pp. 157-172
Author(s):  
Gábor Laborczy ◽  
András Winkler

Abstract It is well known that worldwide deforestation has a negative impact on the global environment. Forests play an important role in producing oxygen as well as retaining gases that create the greenhouse effect. Forests primarily absorb carbon dioxide, the major air pollutant released by the industrial activities. Energy production is the major source of environmental contamination. In addition to reducing CO2 emissions, another issue this industrial sector must tackle is to decrease the use of fossil fuels by substituting them with renewable, environmentally friendly energy sources. One of the answers to these challenges is the utilization of biomass as energy sources. However, biomass-based fuels include short bolts, split round-wood, pulpwood, bark and by-products of sawmilling, which are the raw materials for the wood-based panel industry as well.Wood utilization of the forest products industry has a major impact on the delayed release of carbon dioxide stored in the wood. All over the world, just as in Hungary, the wood-based panel industry mainly uses low quality wood resources and turns them into value added products. The elongation of the life cycle of low quality wood materials decreases CO2 emissions, thus significantly contributing to environmental protection. Furthermore, it is assumed that raw material demand of the wood-based panel industry could be satisfied by focusing on sustainable forest management and well-planned reforestation. Additionally, special energy-plantations may provide extra wood resources, while waste and other non-usable parts of trees contribute to the effective and economic operation of biomass utilizing power-plants. This paper summarizes the current situation of the Hungarian wood-based panel industry and discusses the effects of the panel manufacturing processes on the environment. Also, it outlines the possible future of this important segment of the forest products industry.


Author(s):  
KARPAKAVALLI MEENAKSHISUNDARAM ◽  
PRAKASH GOVINDARAJ ◽  
SIVASUBRAMANIAM P. ◽  
RANJITHKUMAR DHANARAJ ◽  
MOHAN SELLAPPAN

Objective: Algae is the undisputed treasures of the sea and are a valuable raw material, providing unlimited opportunities for new drug discoveries. Marine algal products are in demand in the international market in the form of standardized algal extracts or semi-finished products. Methods: Aqueous and methanolic extracts of Oedogonium globosum and Oedogonium intermedium species were obtained maceration and hot percolation. The active principles from O. intermedium were isolated, purified by column chromatography, and characterized by spectral studies IR, λmax, 1HNMR and MS. The extracts of Oedogonium species were screened for their anti-microbial effects, acute dermal irritation and wound-healing activity studies. Results: Comparing to Oedogonium intermedium (45 %, 90 %, 87 %), very low extractive yields were obtained for Oedogonium globosum (10.80 %, 37 %, 28 %). At phytochemical screening, Terpenoids, Flavanoids and, Glycans were found to be present in a significant amount and upon their isolation, it was found that a collection of fractions from cold extract with Rf value in the range 0.32-0.34 as Glycans and those from the hot extract with 0.40-0.72 as Flavanoids and those from methanolic extracts with 0.23, 0.44 and 0.71 as for Terpenoids. Anti-bacterial study revealed out the fact of Oedogonium species could give higher inhibition to gram-positive than for gram-negative bacteria at (10 μg/10μl/disc) concentration. No symptoms of systemic toxicity and mortality were observed. Silver sulfadiazine, more potent in wound closure, the effect of methanolic extracts of O. intermedium (87 %) was almost at par to the standard (95 %) in action and significantly greater than O. globosum (72 %, P<0.05). Conclusion: Admittedly, Oedogonium type algal species can be known as medicinal algae with a plethora of a wide range of pharmacological activities. Thus, this research work may be considered further for extensive innovative discoveries of new lead molecules and any other pharmacological activities, in the future.


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