Theoretical simulation of cutting edge wear when milling wood and wood based products     

Bolesław Porankiewicz 《Wood Science and Technology》2006,40(2):107-117

Theoretical simulation of cutting edge wearing when milling wood and melamine coated particle board based on stochastical and analytical methods is presented. Abrasion, high temperature corrosion (HTC) and frictional wearing effects are discussed. Results of computations show good correlation between the observed and predicted wear rate for three different experiments. Relations between predicted tool wear rate from HTC, content (C _CP) and size (S _CP) of particles of hard mineral contamination and density (D) of cut material is also presented and discussed.  相似文献   

Cohabitation of tree holes by ants and breeding birds in a temperate deciduous forest     

Sławomir Mitrus  Grzegorz Hebda  Tomasz Wesołowski 《Scandinavian Journal of Forest Research》2016,31(2):135-139

A previously unknown association of ants with birds breeding in tree holes is described. Ants Lasius brunneus Latreille (Hymenoptera: Formicidae) were found in c. 15% of nests of Parus major L. and Poecile palustris L. (Paridae) breeding in tree holes in the primeval deciduous forest located in the Bia?owie?a National Park (Poland). The ants preferably used holes located higher above the ground. As such holes are warmer than the unused holes or other nest sites, it is suggested that the ants cohabit holes utilized by the tits to gain thermal benefits.  相似文献   

The variation of tree-ring widths of Scots pine (Pinus sylvestris L.) affected by air pollution     

Sławomir Wilczyński 《European Journal of Forest Research》2006,125(3):213-219

Using eight populations of Scots pine growing in foothills of the Sudetes (southern Poland) as an example, the character and causes of annual ring variation in 1900–1999 were studied. The climate had a short-term effect on radial growth during the whole period investigated. A long-term decrease of radial growth occurred after 1960, but only in some localities. It was probably caused by non-climatic factors, most likely by industrial pollution. The decline of trees during that period is mainly evidenced by a high variation of width of annual rings, a small similarity of chronologies of annual ring widths, and a lack of signal years. After 1990, the tree recovery process was evident. It was most intensive in localities where the earlier stress was the most severe. Then, trees started to produce wide annual rings, homogeneity of the growth reaction increased, and the signal years began to occur.  相似文献   

High-speed steel tool wear during wood cutting in the presence of high-temperature corrosion and mineral contamination     

Bolesław Porankiewicz  Piotr Iskra  Jakub Sandak  Chiaki Tanaka  Karol Jóźwiak 《Wood Science and Technology》2006,40(8):673-682

Dulling of high-speed steel (HSS) cutting tools after milling five wood species has been analyzed. The wood investigated varied in mineral contamination, high-temperature corrosivity (HTC) and density (D). Experiments performed proved that up to date methods for evaluation of mineral contamination in wood should be improved. A new pipe-like form of mineral contamination particles was evidenced. The correlation between the presence of 3D aggregates of silica in wood and high content of K and Ca in the ash was established. Employing multivariable theoretical simulation method, the combined effect of mineral contamination, HTC and wood density on the tool dullness appeared to be a reasonable explanation of the results obtained.  相似文献   

Co‐expression of PACAP with VIP,SP and CGRP in the Porcine Nodose Ganglion Sensory Neurons          下载免费PDF全文

L. Rytel  K. Palus  J. Całka 《Anatomia, histologia, embryologia》2015,44(2):86-91

Our previous study revealed the expression of substance P (SP) and calcitonin gene‐related peptide (CGRP) in sensory distal ganglion of the vagus (nodose ganglion) neurons in the pig. As these neuropeptides may be involved in nociception, the goal of these investigations was to determine possible expression of vasoactive intestinal polypeptide (VIP), SP and CGRP in the pituitary adenylate cyclase‐activating polypeptide‐immunoreactive (PACAP‐IR) porcine nodose perikarya. Co‐expression of these substances was examined using a double‐labelling immunofluorescence technique. To reveal the ganglionic cell bodies, the pan‐neuronal marker protein gene product 9.5 (PGP 9.5) was used. Quantitative analysis of the neurons revealed that 67.25% of the PGP 9.5+ somata in the right‐side ganglion and 66.5% in the left side, respectively, co‐expressed PACAP‐IR. Moreover, 60.6% of the PACAP‐IR cells in the right‐side ganglion and 62.1% in the left, respectively, co‐expressed VIP. SP‐IR was observed in 52.2 and 39.9% of the right and left ganglia, respectively. CGRP was found in 27.7 and 34.1% of the right and left distal ganglion of the vagus, respectively. High level of co‐expression of PACAP with VIP, SP and CGRP in the distal ganglia of the vagus sensory perikarya directly implicates studied peptides in their functional interaction during nociceptive vagal transduction.  相似文献   

Erratum to: Spatial variability of close-to-primeval Fagus–Abies–Picea forests in the Western Carpathians (Central Europe): a step towards a generalised pattern     

Jarosław G. Paluch  Zbigniew Kołodziej  Maciej Pach  Rafał Jastrzębski 《European Journal of Forest Research》2015,134(2):389-389

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Spatial variability of close-to-primeval Fagus–Abies–Picea forests in the Western Carpathians (Central Europe): a step towards a generalised pattern     

Jarosław G. Paluch  Zbigniew Kołodziej  Maciej Pach  Rafał Jastrzębski 《European Journal of Forest Research》2015,134(2):235-246

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Desiccation tolerance and cryopreservation of seeds of black poplar (Populus nigra L.), a disappearing tree species in Europe     

Marcin Michalak  Beata P. Plitta  Tadeusz Tylkowski  Paweł Chmielarz  Jan Suszka 《European Journal of Forest Research》2015,134(1):53-60

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Plant P5C reductase as a new target for aminomethylenebisphosphonates     

Forlani G  Giberti S  Berlicki L  Petrollino D  Kafarski P 《Journal of agricultural and food chemistry》2007,55(11):4340-4347

A series of N-substituted derivatives of aminomethylenebisphosphonic acid were evaluated as potential inhibitors of delta1-pyrroline-5-carboxylate reductase (EC 1.5.1.2), the enzyme that catalyzes the last step in proline biosynthesis, partially purified from Arabidopsis thaliana suspension cultured cells. At millimolar concentrations, three compounds out of 26 were found to interfere with the catalytic mechanism. One of them, namely, 3,5-dichloropyridyl-aminomethylenebisphosphonic acid, retained such inhibitory activity in the micromolar range. Kinetic analyses ruled out the possibility that the inhibition could simply rely upon the chelating properties of bisphosphonates and showed mechanisms of a noncompetitive type against NADH and an uncompetitive type against delta1-pyrroline-5-carboxylic acid, with KI values of 199 +/- 6 and 10.3 +/- 1.5 microM, respectively. A computer-aided docking analysis, performed on the basis of the crystal structure of the enzyme from Streptococcus pyogenes, suggested that this phosphonate may interact with amino acid residues near the binding site of delta1-pyrroline-5-carboxylic acid, thus blocking the substrate in a pocket and preventing its interaction with NADH. Because in higher plants the step catalyzed by delta1-pyrroline-5-carboxylate reductase is shared by all pathways leading to proline synthesis, such a compound may represent a lead structure to be exploited for the design of new substances endowed with herbicidal activity.  相似文献   

Survival,growth and photochemical efficiency of silver fir seedlings produced with different technologies     

Robakowski  Piotr  Pietrzak  Tomasz  Kowalkowski  Wojciech  Małecki  Grzegorz 《New Forests》2021,52(6):1055-1077

New Forests - Forest tree seedling production technologies impact reforestation success determined with survival and quality of seedlings. Five Abies alba seedling production technologies were...  相似文献