Comparing the Effect of Chemical and Physical Properties on Complex Electrical Impedance of Scots Pine Wood

Holzforschung ◽  
2003 ◽  
Vol 57 (4) ◽  
pp. 433-439 ◽  
Author(s):  
M. Tiitta ◽  
P. Kainulainen ◽  
A. M. Harju ◽  
M. Venäläinen ◽  
A.-M. Manninen ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Moisture Content ◽  
Physical Properties ◽  
Scots Pine ◽  
Complex Impedance ◽  
Chemical Properties ◽  
Brown Rot ◽  
Resin Acids ◽  
Extractive Content ◽  
Pine Trees

Summary This study examined the effects of physical (moisture content, water content and wood density) and chemical properties (concentration of phenolics and resin acids) on the electrical properties of Scots pine (Pinus sylvesteris L.) wood specimens. Complex impedance was measured from heartwood and sapwood specimens using frequencies between 5 kHz and 1 MHz. Significant correlation between density and electrical properties was found at high frequencies with sapwood specimens in which the extractive content was low. Moisture content had an effect on electrical properties over the whole frequency range. Electrical properties of heartwood samples with high extractive content were differently affected by the chemical and physical properties. Electrical properties were sufficient to distinguish between the samples from the brown-rot resistant and susceptible Scots pine trees.

Differences in Resin Acid Concentration between Brown-Rot Resistant and Susceptible Scots Pine Heartwood

Holzforschung ◽  
2002 ◽  
Vol 56 (5) ◽  
pp. 479-486 ◽  
Author(s):  
A. M. Harju ◽  
P. Kainulainen ◽  
M. Venäläinen ◽  
M. Tiitta ◽  
H. Viitanen
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Scots Pine ◽  
Abietic Acid ◽  
Resin Acid ◽  
Brown Rot ◽  
Decay Resistance ◽  
Resin Acids ◽  
Hydrophobic Properties

Summary The concentration of individual resin acids and the equilibrium moisture content at a relative humidity of 100% were studied in brown-rot resistant and susceptible Scots pine (Pinus sylvestris L.) heartwood. About 90% of the resin acids in the heartwood were of the abietane type, abietic acid being the most abundant. The concentration of resin acids was higher in the decay-resistant heartwood than in the decay-susceptible heartwood. Resin acids are presumably in part responsible for the decay resistance of Scots pine heartwood. However, no clear relationship was found between the concentration of resin acids and the equilibrium moisture content. The role of resin acids may also be ascribed to mechanisms other than their hydrophobic properties alone. The reasons for the slight differences in moisture content between the decay classes require further study.

The Distribution and Composition of Extractives in Jack Pine Trees

1973 ◽  
Vol 3 (4) ◽  
pp. 516-521 ◽  
Author(s):  
G. D. Sinclair ◽  
D. K. Dymond
Keyword(s):  
Chromatographic Analysis ◽  
Jack Pine ◽  
Resin Acids ◽  
Extractive Content ◽  
Single Tree ◽  
Pine Trees ◽  
Liquid Chromatographic Analysis ◽  
Different Diameters ◽  
Liquid Chromatographic

The distribution of acetone-soluble extractives in jack pine trees of different diameters, and at different locations within a single tree was studied. The amount of extractives varied from 3% in a 10 cm diameter tree to 9.6% in a 50 cm diameter tree. Within a single tree the top had the least amount of extract, 2.7%, while the needle bearing twigs had the greatest amount, 4.6%. Gas–liquid chromatographic analysis of the extracts showed that the composition was relatively similar for all sizes of trees and within one tree except in the top and the branches. The heartwood of the tree had a much higher extractive content than the sapwood and contained a higher concentration of resin acids, pinocembrin, and pinobanksin.

scholarly journals The Physical Properties and The Extractive Content of Sugar Palm Stem (Arenga pinnata)

2019 ◽  
Vol 2 (1) ◽  
pp. 37-46
Author(s):  
Rudi Hartono ◽  
Muhdi ◽  
John Parulian Nainggolan
Keyword(s):  
Physical Properties ◽  
Cold Water ◽  
Outer Part ◽  
Chemical Properties ◽  
Specific Weight ◽  
Hot Water ◽  
Extractive Content ◽  
Weight Density ◽  
Palm Sugar ◽  
Physical And Chemical

This study aims to determine the physical and chemical properties of sugar palm. Physical properties include moisture content, density, and shrinkage from wet to dry oven chemical properties included of extractive solubility in cold and wet solutions. The samples were 15 years of age and originated from Sidikalang, Dairi district, North Sumatra. Three individual samples were taken and cut into 50 cm of length of three types of height namely base, middle, and end. The research was also conducted horizontally (edge, center, and at the core). The results of this study indicated that the average water content was 120.31-603.48%, the specific weight was 0.12-0.51 g/cm3, and the shrinkage from wet to dry oven was 28.06-77.69%. The extractive solubility in cold water was 11.66-87.22%, while in hot water was 10-90%. Based on the specific weight/density obtained, the outer part or edge of the palm sugar was included in the strength classes IV and V.

scholarly journals Effects of silvicultural techniques on the diversity of microorganisms in forest soil and their possible participation in biological control of Armillaria and Heterobasidion

2015 ◽  
Vol 55 (3) ◽  
pp. 241-253 ◽  
Author(s):  
Hanna Kwaśna ◽  
Lucyna Walkowiak ◽  
Piotr Łakomy ◽  
Jolanta Behnke-Borowczyk ◽  
Roman Gornowicz ◽  
...  
Keyword(s):  
Biological Control ◽  
Scots Pine ◽  
Chemical Properties ◽  
Soil Surface ◽  
Soft Rot ◽  
Biological Properties ◽  
Clear Cut ◽  
Wood Debris ◽  
Pine Trees ◽  
Formed Part

AbstractEffects of different pre-planting soil preparations and post-harvest wood debris applications in a clear-cut Scots pine plantation, on the abundance, diversity, and activity of culturable microorganisms were investigated. The investigation was done 9 years after the re-plantings had been done. This formed part of an investigation of silvicultural practices for conservation and the biological control ofArmillariaandHeterobasidionin northern temperate forests (Poland). The treatments being compared, were expected to have altered the soil’s physical and chemical properties, and consequently, its biological properties. Only soft-rot microfungi from the Ascomycota and Zygomycota were detected in the soil. Fungi, including those antagonistic toArmillariaandHeterobasidion, were more abundant after shallow ploughing than after deep ploughing or ridging, and where chipped rather than coarse wood debris was left on the soil surface or incorporated. Scots pine trees had the most biomass and the least mortality after ridging and leaving coarse wood debris on the surface (associated with only a relatively moderate abundance of fungi).

scholarly journals Determination of Physico-chemical properties of selected tropical timbers in Anambra State, South Eastern Nigeria

2021 ◽  
Vol 46 (2) ◽  
Author(s):  
G.C NWANISOBI ◽  
C. EJIKEME EZECHI ◽  
C. U OKEKE
Keyword(s):  
Specific Gravity ◽  
Moisture Content ◽  
Physical Properties ◽  
Cold Water ◽  
Chemical Constituents ◽  
Chemical Properties ◽  
Anambra State ◽  
Physico Chemical ◽  
Porosity Index

The analyses on chemical properties of some tropical timbers have been studied. The physical properties of these timbers varied in the pH(4.26 – 6.85) , moisture content(13%-37%), specific gravity(0.16-0.45), charring temperature (61 – 116o C)and porosity index(1.17-2.08%).Also the solubility behaviors of these timbers were mostly insoluble in hot and cold water, NaOH and ethanol and slightly soluble in concentrated HCl and H2SO4 respectively. The Qualitative results show heavy presence of flavonoids, saponins, tannis, glycosides, steroids and terpenoids in some of the timbers.Quantitative determinations were carried out and results show that the woods contain chemical constituents which are useful to both humans and industries.

Effect of Moisture Content and Screw Speed on the Physical Chemical Properties of an Extruded Crab-based Snack

2005 ◽  
Vol 11 (2) ◽  
pp. 121-127 ◽  
Author(s):  
V. A. Obatolu ◽  
D. I. Skonberg ◽  
M. E. Camire ◽  
M. P. Dougherty
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Chemical Properties ◽  
Value Added ◽  
Expansion Ratio ◽  
Screw Speed ◽  
Twin Screw ◽  
L Value ◽  
By Products ◽  
Value Added Products

Crab processing generates by-products that could be used in new value-added products to decrease processing waste and increase profits. In this product development study, the effects of moisture content and screw speed on physical properties and composition of an extruded crab-based snack product were investigated. Corn meal was fortified with 10% ground crab leg and passed through a twin-screw extruder using moisture contents of 25% and 30% and screw speeds of 200, 250 and 300rpm for a total of six treatments, extruded in duplicate. Screw speed and moisture content had a significant (p 0.05) influence on moisture content, expansion ratio, crunchiness and L-value of the extrudate while protein, fat, ash and mineral were not significantly (p 0.05) affected. As screw speed increased, moisture content and bulk density of the extrudates decreased. The snack product extruded at 25% moisture content and 300rpm had significantly different (p 0.05) physical properties compared to all other treatments. Increases in torque and melting temperature were observed for higher screw speed and lower extruding moisture content.

Phenolic and Lipophilic Extractives in Scots Pine Knots and Stemwood

Holzforschung ◽  
2003 ◽  
Vol 57 (4) ◽  
pp. 359-372 ◽  
Author(s):  
S. Willför ◽  
J. Hemming ◽  
M. Reunanen ◽  
B. Holmbom
Keyword(s):  
Phenolic Compounds ◽  
Scots Pine ◽  
Abietic Acid ◽  
Radial Direction ◽  
Resin Acid ◽  
Complex Mixture ◽  
Monomethyl Ether ◽  
Resin Acids ◽  
Pine Trees ◽  
Outer Branch

Summary The phenolic and lipophilic extractives in the heartwood of knots from seven Scots pine trees were analysed by GC, GC-MS and HPSEC. The knots contained large amounts of phenolic stilbenes, 1–7% (w/w), and lignans, 0.4–3% (w/w), while the stemwood contained around 1% (w/w) of stilbenes and no detectable lignans. In young trees without stem heartwood the stilbene content in the knots was up to 200 times that in the stem. Some in-tree and between-tree variation was seen in the content of phenolic compounds in the knots. The ratio of pinosylvin monomethyl ether to pinosylvin was higher in the knots than in the stemwood. The most abundant lignan was nortrachelogenin, but also matairesinol, secoisolariciresinol and liovil were present in small amounts in the knots. The knots also contained a complex mixture of lignan-like compounds, here called oligolignans. The flavonoid pinocembrin was present in both stemwood and knots in amounts below 0.02% (w/w). The stilbene concentration in the radial direction, from the pith to the outer branch, decreased or was on the same level inside the stem, while it decreased markedly in the outer branch. The lignan concentration was on the same level or decreased slightly inside the stem, while it decreased markedly in the branches and became almost non-existent within 10 cm out in the branches. The knots contained large amounts (4.5–32% (w/w)) of lipophilic extractives, mainly resin acids. Some in-tree and between-tree variation was seen for the resin acids. The abietane-type resin acids dominated over the pimarane-type acids and abietic acid was the most abundant resin acid in the knots and in stem heartwood. The amount of resin acids in the radial direction decreased or was on the same level inside the stem, while a clear decrease was detected in the branches. The profile of the distribution of resin acids and phenolic compounds was similar. The knots also contained up to 0.5% (w/w) of diterpenyl aldehydes.

KARAKTERISASI SIFAT FISIKA DAN KIMIA CUKA KAYU DARI TANDAN KOSONG KELAPA SAWIT

2014 ◽  
Vol 6 (1) ◽  
pp. 35 ◽  
Author(s):  
Rizka Karima
Keyword(s):  
Specific Gravity ◽  
Physical Properties ◽  
Solid Waste ◽  
Ph Value ◽  
Total Yield ◽  
Chemical Properties ◽  
Phenol Content ◽  
Empty Fruit Bunches ◽  
Wood Vinegar ◽  
And Chemical Properties

There’s so many pal solid waste or palm empty fruit bunches, but the utilization is not maximized, this research its to optimized utilization of palm solid waste to be wood vinegar and want to know the composition physical properties and chemical properties of wood vinegar from palm empty fruit bunches. Total yield of wood vinegar from palm empty fruit bunches its 15,94 % and total yield of charcoal its 64,58 %. GCMS result showing chemical properties from wood vinegar of burning < 100oC its obtained 19 compound and burning >100 oC its obtained 6 compound. The result physichal properties testing from crued wood vinegar its obtained specific gravity 1,0005 and 1,0010, pH value are 3,233 and 3,186, TAT content are 9,36 % and 11,12 %, phenol content its 0,44 %. The result physical properties testing from wood vinegar which has decolorizatin by activated carbon its obtained specific gravity are 0,9987 and 0,999, pH value are 3,036 and 3,012, TAT content are 8,29 % and 9,27 % and phenol content its 0,01 %.Keywords: palm bunches, wood vinegar, liquid smoke

Primary involvement of K+ conductance in membrane resonance of trigeminal root ganglion neurons

1988 ◽  
Vol 59 (1) ◽  
pp. 77-89 ◽  
Author(s):  
E. Puil ◽  
B. Gimbarzevsky ◽  
I. Spigelman
Keyword(s):  
Electrical Properties ◽  
Channel Blocker ◽  
Complex Impedance ◽  
Membrane Potentials ◽  
K Channel ◽  
Bathing Medium ◽  
Trigeminal Root ◽  
Membrane Resonance ◽  
Ganglion Neurons ◽  
Impedance Magnitude

1. The complex impedances and impedance magnitude functions were obtained from neurons in in vitro slices of trigeminal root ganglia using frequency-domain analyses of intracellularly recorded voltage responses to specified oscillatory input currents. A neuronal model derived from linearized Hodgkin-Huxley-like equations was used to fit the complex impedance data. This procedure yielded estimates for membrane electrical properties. 2. Membrane resonance was observed in the impedance magnitude functions of all investigated neurons at their initial resting membrane potentials and was similar to that reported previously for trigeminal root ganglion neurons in vivo. Tetrodotoxin (10(-6) M), a Na+-channel blocker, applied in the bathing medium for 20 min produced only minor changes, if any, in the resonance, although gross impairment of Na+-spike electrogenesis was apparent in most of the neurons. Brief applications (1-5 min) of a K+-channel blocker, tetraethylammonium (TEA; 10(-2) M), increased the impedance magnitude and abolished, in a reversible manner, the resonant behavior. In all cases, the resonant frequency was decreased by TEA administration prior to total blockade of resonance. 3. The TEA-induced blockade of resonance was associated with decreases in the estimates of the membrane conductances, without significant alterations of input capacitance. A particularly large decrease was observed in Gr, the time-invariant resting conductance that includes a lumped leak conductance component. The voltage- and time-dependent conductance, GL, and associated relaxation time constant, tau u, also declined progressively during administration of TEA. 4. Systematic variations in the membrane potentials of trigeminal root ganglion neurons were produced by intracellular injections of long-lasting step currents with superposition of the oscillatory current stimuli, in order to assess the effects of TEA on the relationship of the electrical properties to the membrane potential. Applications of TEA led to a depolarizing shift in the dependence of the membrane property estimates, suggesting voltage-dependence of the effects of TEA on presumed K+ channels in the membrane. 5. These data suggest a primary involvement of K+ conductance in the genesis of membrane resonance. This electrical behavior or its ionic mechanism is a major modulator of the subthreshold electrical responsiveness of trigeminal root ganglion neurons.

scholarly journals Chemical and Physical Properties of Some Hazelnut Varieties Grown in Portugal

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1476
Author(s):  
Ana Cristina Ferrão ◽  
Raquel P. F. Guiné ◽  
Elsa Ramalhosa ◽  
Arminda Lopes ◽  
Cláudia Rodrigues ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Physical Properties ◽  
Water Activity ◽  
Induction Time ◽  
Oxidation Stability ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Nutritional Characteristics ◽  
Physical And Chemical ◽  
And Chemical Properties

Hazelnuts are one of the most appreciated nuts worldwide due to their unique organoleptic and nutritional characteristics. The present work intended to analyse several physical and chemical properties of different hazelnut varieties grown in Portugal, namely Tonda de Giffoni, Grada de Viseu, Segorbe, Longa de Espanha, Butler, Gunslebert, and Negreta. In general, the results revealed statistically significant differences between the varieties under study. The Gunslebert had more elongated hazelnuts and with heavier shelled fruits, while the kernels of the Grada de Viseu revealed to be heavier. Grada de Viseu was harder in the shell, Gunslebert had a harder core, and Segorbe was more resistant to fracture. Fat was the more representative component for all varieties and in some cases the values of moisture and water activity were over the recommended amount (≥0.62). Tonda de Giffoni was the variety with the highest induction time, indicating the highest oxidation stability. Moreover, discriminant analysis revealed that the variables more important to distinguish the varieties were protein (λ = 0.007) and water activity (λ = 0.010). The results of this study help to better understand the differences between some hazelnut varieties that are cultivated in Portugal, which gives important hints for all players in the hazelnut sector.

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