In this research, two motor-manual felling & processing methods were compared, assortment and half-tree length, in beech stands. Investigation was done in two compartments in the northern part of ...Bosnia and Herzegovina (B&H), where four sample plots were chosen that differed by felled tree diameter and harvesting method. On the sample plots A1 and B1 assortment harvesting method was performed and on the sample plots A2 and B2 half-tree length method. In the study, 318 trees were felled in total, of which 163 by the assortment method and 155 by the half-tree length method. With the increase of DBH, productivity was constantly increasing and it was higher when the half-tree length method was applied than the assortment method. The main reason why half-tree length was more productive was the fact that some working operations, like production and stacking of fuel wood, were avoided or minimized. Keywords: motor-manual, assortment, half-tree length, productivity
Different types of shelterwood system and group selection forests were studied to discover the extent of damage caused by logging.Motor-manual cutting and mainly tractor skidding were included. ...Sampling transects were used to estimate the damage to young forest and remaining stands. The whole research area was regenerated on average 31%, of which 21% was damaged. We found a higher density of designated and undesignated skid trails on larger regeneration areas. Damage to young forest and damage to remaining productive stands were compared. In this respect the whole rotation period was divided into three time intervals, the first of which designated a mixed pattern of young forest area and younger phases prior to commercial thinning, in which the last of the old mature trees are removed. The second phase is a mix of currently productive stands and some young forest, in which the first and second commercial thinnings begin, until the final stage, in which young forest becomes increasingly abundant and perspective. In the last period, damage to productive stands is high (around 70%), since they have accumulated over a long time period. The fact that better forest stand opening with skid trails means less damage to young forest, but slightly more damage to mature stands suggests the conclusion that the abundance and position of young forest patches should dictate the density and position of skid trails.
This paper deals with the problem of tree damage in a remaining stand. Two models were used for assessment of stand damage over the entire production period. Damage accumulates on the trees and in ...the stand, which is why the total share of damage tends towards the limit 100% if the number of thinnings increases. Parameters used in the models were established partly by previous field measurements and partly by simulations measurements. Motor- manual and cut-to-length technologies were analysed and compared according to the total number of damaged trees and the structure of trees according to the number of injuries. It was found that motor-manual technology causes more damage to trees and results in worse tree structure, meaning more than one injury. Many unanswered questions provide plenty of opportunities for further research.
Monoliths are chromatographic stationary phases, which were specially designed for efficient purification of large biomolecules, like proteins, viruses and DNA. In this work, the small scale ...monolithic butyl (C4) and styrene-divinyl benzene (SDVB) columns were applied for reversed phase analyses of various degraded influenza viruses. The binding of the HA1 subunit of haemagglutinin to the monolithic columns was confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and the Western blot. The working linear range was determined as 1.60
×
10
10 viral particles/mL to at least 1.64
×
10
11 viral particles/mL, the limit of detection was found to be 2.56
×
10
9 virus particles/mL and the limit of quantification was 5.12
×
10
9 virus particles/mL. The analytical HPLC method developed with the H1N1 virus was also applicable for the analytics of the HA1 subunit of H3N2 influenza virus and the influenza B virus.
Model development and use play a significant role in research and forest management of Slovenian forests. As co-natural and sustainable forest management is traditional, it is essential to rely on ...available knowledge of the composition of natural plant associations. This paper describes the need for stumpage price modelling, and the basic concept of developing models which can behave dynamically as forest structure approaches the final goal – tree composition close to nature. The main plant associations in Slovenia and their characteristic tree structure represent the so called model goal. Input data are taken from forest inventory base and are compared with the model goal. The difference between the model and true tree structure together with growth and other variables gives the intensity and structure of prescribed annual cut and consequently the value of wood assortments. The model produced several possible scenarios for the next decades, and this has already proved tobe a good basis for decision making.
•The odds of accident among professional fellers are highest during routine work.•The odds of accident are lowest during salvage and sanitation cutting.•The odds of accident increase with the slope ...and total volume of felled trees.•Work pace and techniques have to be adjusted to the working conditions.
The increasing share of forests that are damaged due to natural disturbances potentially increases the risk of accident when cutting the affected forests. The main goal of the study was to analyse the odds of accident by type and causes of cutting. The study was based on 316 accidents among professional fellers during cutting in Slovenian state forests over a 7-year period. The two most rational binary logistic models were selected by using Akaike’s Information Criterion. The research results indicated that the odds of accident increase with the slope of the terrain and total volume of felled trees. Contrary to expectations, the odds of accident are highest during the cutting of individual healthy and undamaged trees, lower in deforestation due to urbanisation and infrastructure requirements, which is similar to clearcutting, and lowest during the cutting of trees damaged by biotic and abiotic factors. As an individual cause of accident, cutting trees damaged by insects, fires and emissions is the least dangerous, while cutting trees damaged by glaze ice and snow is the most dangerous. The results indicate that, in addition to natural factors, the likelihood of cutting-related accidents also depends on the time of exposure to hazards, type of harvesting and tree characteristics. On the basis of the results, it is concluded that measures to reduce the likelihood of professional fellers must be particularly focused on routine tasks and on adjusting the work pace and technique to the working conditions.
The study presents the procedure and functioning of themodel for large-scale determination of wood skidding direction on steep slopes. The determination of wood skidding direction significantly ...depends on the position of the forest stand and the adjacent forest road, the characteristics of skid trail /ground/ and forest operation technology with special attention to the applied skidding means. The model evaluation of wood skidding direction is determined on the basis of forest road layout on the slope (slope, valley and ridge). The data of digital terrainmodel and digitalized forest road network were used as source data. The software can be modified according to specific technology needs by increasing the range and/or the level of suitability of individual wood skidding directions between two roads. The classification is presented for case study Forest Management Unit comprising 3000 ha. The application of the model discussed, as wll as its limitation and adaptation to changing technological condition and its development in the future.
Chemical and chromatographic stability of methacrylate-based monolithic columns bearing 3-
N,
N-diethylamino-2-hydroxypropyl (DEAE) and quarternary amine (QA) groups was studied. The leakage products ...from both monolithic columns were determined and the leakage of amines has been quantified in alkali solutions. Monolithic columns bearing QA functional groups being exposed to 1
M sodium hydroxide solution for up to 3 months caused reduction of ion-exchange groups for approximately 12%, while for DEAE monolithic columns was only around 3% in 1 year. In 0.1
M NaOH and 20% ethanol degradation was significantly lower. The main leaking compound from DEAE monolith was found to be 3-(diethylamino)-1,2-propanediol and 2,3-dihydroxypropyltrimethylammonium salt for QA monolith. During repeated 50 cleaning-in-place (CIP) cycles, no changes in chromatographic properties were detected.
In this research, two motor-manual felling & processing methods were compared, assortment and half-tree length, in beech stands. Investigation was done in two compartments in the northern part of ...Bosnia and Herzegovina (B&H), where four sample plots were chosen that differed by felled tree diameter and harvesting method. On the sample plots A1 and B1 assortment harvesting method was performed and on the sample plots A2 and B2 half-tree length method. In the study, 318 trees were felled in total, of which 163 by the assortment method and 155 by the half-tree length method. With the increase of DBH, productivity was constantly increasing and it was higher when the half-tree length method was applied than the assortment method. The main reason why half-tree length was more productive was the fact that some working operations, like production and stacking of fuel wood, were avoided or minimized.
Different types of shelterwood system and group selection forests were studied to discover the extent of damage caused by logging.Motor-manual cutting and mainly tractor skidding were included. ...Sampling transects were used to estimate the damage to young forest and remaining stands. The whole research area was regenerated on average 31%, of which 21% was damaged. We found a higher density of designated and undesignated skid trails on larger regeneration areas. Damage to young forest and damage to remaining productive stands were compared. In this respect the whole rotation period was divided into three time intervals, the first of which designated a mixed pattern of young forest area and younger phases prior to commercial thinning, in which the last of the old mature trees are removed. The second phase is a mix of currently productive stands and some young forest, in which the first and second commercial thinnings begin, until the final stage, in which young forest becomes increasingly abundant and perspective. In the last period, damage to productive stands is high (around 70%), since they have accumulated over a long time period. The fact that better forest stand opening with skid trails means less damage to young forest, but slightly more damage to mature stands suggests the conclusion that the abundance and position of young forest patches should dictate the density and position of skid trails.
