scholarly journals Effects of Coniophora puteana (Schumach.) P. Karst. Fungus on the decomposition of sessile oak wood

2016 ◽  
pp. 37-47
Author(s):  
Miroslava Marković ◽  
Snežana Rajković
Keyword(s):  
Mass Loss ◽  
Compression Strength ◽  
Brown Rot ◽  
Regression Equations ◽  
Initial Value ◽  
Oak Wood ◽  
Sessile Oak ◽  
Coniophora Puteana ◽  
Dependent Variables ◽  
Independent Variable

The paper examines the effects of a brown rot agent-Coniophora puteana (Schumach.) P. Karst on the mass loss and compression strength of sessile oak (Q. petraea agg) wood. The wood mass loss of Q. petraea agg., caused by C. puteana amounted to 1.5, 2.12 and 2.23 after 2, 4 and 6 months respectively. The obtained values indicate that the biggest mass loss of wood occurred in the first two months. Compression strength also decreased under the influence of C. puteana. In comparison to its initial value (100%), it amounted to 92.13, 90.72 and 76.25 after 2, 4 and 6 months. The analysis of the correlation between the sessile oak mass loss-G m and compression strength decrease- p (dependent variables) and the incubation time (T-independent variable) revealed a strong correlation between the variables and the following regression equations were obtained: G m = 0.0638492 + 0.954107 x T  p = 96.328-2.666 x T

scholarly journals CHANGES IN GROSS CALORIFIC VALUE OF THERMALLY TREATED SCOTS PINE (PINUS SYLVESTRIS L.) AND SESSILE OAK (QUERCUS PETRAEA L.) WOOD AND THEIR EXPLANATION USING FTIR SPECTROSCOPY

Wood Research ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 243-254
Author(s):  
Emília Orémusová ◽  
Eva Výbohová
Keyword(s):  
Pinus Sylvestris ◽  
Mass Loss ◽  
Ftir Spectroscopy ◽  
Scots Pine ◽  
Calorific Value ◽  
Quercus Petraea ◽  
Gross Calorific Value ◽  
Pine Wood ◽  
Oak Wood ◽  
Sessile Oak

Scots pine (Pinus sylvestris L.) and Sessile oak (Quercus petraea L.) wood were thermally treated in an oven at the temperatures of 160°C, and 200°C under atmospheric pressure in the presence of air for 3 and 9 hrs. The mass loss and gross calorific value were determined. Non-treated wood samples achieved a gross calorific value of 22 193 J.g-1 for pine wood and 19 277 J.g-1 for oak wood. Whereas the calorific value of pine wood with increasing severity of treatment decreased, in the case of oak it increased. The mass loss increased with increasing treatment severity by both wood species. Mentioned differences in pine and oak wood behaviour using ATR-FTIR spectroscopy were explained. In the case of pine wood with increasing temperature and time of exposure a decrease of resin acids was observed. This may be contributed to decrease in GCV. In the case of oak wood, mainly at temperature of 200°C the degradation of hemicelluloses was observed that results in relative increasing in the lignin content with followed increase in the GCV.

The digestible and metabolizable energy value of copra meals and their prediction from chemical composition

1989 ◽  
Vol 49 (3) ◽  
pp. 459-466 ◽  
Author(s):  
P. J. Thorne ◽  
J. Wiseman ◽  
D. J. A Cole ◽  
D. H. Machin
Keyword(s):  
Basal Diet ◽  
Metabolizable Energy ◽  
Regression Equations ◽  
Crude Fibre ◽  
Chemical Measurements ◽  
Dependent Variables ◽  
Single Chemical ◽  
Gross Energy ◽  
Independent Variable ◽  
Image Position

ABSTRACTDigestible (DE) and metabolizable (ME) energy values for five copra meals and a sample of raw copra, with oil contents ranging from 4 to 662 g/kg, were determined with both a high and a low energy basal diet in a metabolism experiment using 16 female pigs. Determined DE values ranged from 12·68 to 29·92 MJ/kg dry matter (DM) and values for ME from 11·95 to 29·08 MJ/kg DM which was a reflexion of their residual oil contents. Regression equations for the six samples were derived with DE and ME as dependent variables and chemical measurements and gross energy as independent variables. The best equation based on a single chemical parameter (ether extract (EE)) was:Improvements associated with including more than one independent variable in the regression analysis were marginal. The most accurate equation (in terms of minimized residual s.d.) based on EE and crude fibre (CF) was:

scholarly journals THE AGE AND DENSITY OF ANCIENT AND MODERN OAK WOOD IN STREAMS AND SEDIMENTS

IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 345-353 ◽  
Author(s):  
Richard P. Guyette ◽  
Mike Stambaugh
Keyword(s):  
Residence Time ◽  
Regression Equations ◽  
Large Wood ◽  
Coarse Scale ◽  
Oak Wood ◽  
Long Period ◽  
Oak Trees ◽  
Dating Methods ◽  
Dependent Variables ◽  
The Relationship

Large wood of oak trees (Quercus spp.) has resided in the streams and sediments of north Missouri, USA for many thousands of years. This wood affords the opportunity to compare a chronosequence of differences in wood density over a very long period. We analyzed the relationship between the age (residence time) and density of heartwood from oak boles using tree-ring and 14C dating methods and discuss their implications. The residence time of large oak wood (> 25 cm diameter) sampled in the streams and sediments ranged from less than 14 years to more than 12,320 years. The oak wood ranged in density from 0.82 g cm-3 for a tree that had recently fallen into the stream to 0.14 g cm-3 for ancient oak wood. Two regression equations relate age (residence time) and density of oak wood and explain 88 percent of the variance in the dependent variables. Equation 1, heartwood density = age, can be used for studies in carbon cycling, wood as invertebrate habitat, or other questions related to the density and ecology of wood in streams such as wood retention and export. Equation 2, age = heartwood density, can be used for estimating when oak wood was formed on a very coarse scale over many thousands of years.

scholarly journals The gradient nature ofs-lenition in Caleño Spanish

2011 ◽  
Vol 23 (2) ◽  
pp. 223-243 ◽  
Author(s):  
Richard J. File-Muriel ◽  
Earl K. Brown
Keyword(s):  
Symbolic Representation ◽  
Speaking Rate ◽  
Final Position ◽  
Lexical Frequency ◽  
Word Position ◽  
Dependent Variables ◽  
Independent Variable ◽  
Linear Regressions

AbstractWhereas previous studies of Spanishs-weakening have relied on impressionistic coding, the present study examines temporal and gradient acoustic details in the production of /s/ by eight females from Cali, Colombia, during sociolinguistic interviews. We propose a metric for quantifyings-realization by employing three scalar-dependent variables:s-duration, centroid, and voicelessness. The results of linear regressions indicate that the dependent variables are significantly conditioned by local speaking rate, word position, following and preceding phonological context, stress, and lexical frequency. This study sheds light on how each independent variable influencess-realization acoustically. For example, as local speaking rate increases, duration, centroid, and voicelessness decrease, which is indicative of lenition, and the same weakening tendency is observed when /s/ occurs in word-final position or is followed by a nonhigh vowel, whereas frequency contributes only tos-duration. We discuss the advantages of opting for instrumental measurements over symbolic representation.

scholarly journals Seemingly Unrelated Mixed-Effects Biomass Models for Black Locust in West Poland

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 380
Author(s):  
Karol Bronisz ◽  
Szymon Bijak ◽  
Rafał Wojtan ◽  
Robert Tomusiak ◽  
Agnieszka Bronisz ◽  
...  
Keyword(s):  
Black Locust ◽  
Random Effect ◽  
Tree Height ◽  
Cross Model ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Dependent Variables ◽  
Dry Biomass ◽  
Biomass Components ◽  
Independent Variable

Information about tree biomass is important not only in the assessment of wood resources but also in the process of preparing forest management plans, as well as for estimating carbon stocks and their flow in forest ecosystems. The study aimed to develop empirical models for determining the dry mass of the aboveground parts of black locust trees and their components (stem, branches, and leaves). The research was carried out based on data collected in 13 stands (a total of 38 sample trees) of black locust located in western Poland. The model system was developed based on multivariate mixed-effect models using two approaches. In the first approach, biomass components and tree height were defined as dependent variables, while diameter at breast height was used as an independent variable. In the second approach, biomass components and diameter at breast height were dependent variables and tree height was defined as the independent variable. Both approaches enable the fixed-effect and cross-model random-effect prediction of aboveground dry biomass components of black locust. Cross-model random-effect prediction was obtained using additional measurements of two extreme trees, defined as trees characterized by the smallest and largest diameter at breast height in sample plot. This type of prediction is more precise (root mean square error for stem dry biomass for both approaches equals 77.603 and 188.139, respectively) than that of fixed-effects prediction (root mean square error for stem dry biomass for both approaches equals 238.716 and 206.933, respectively). The use of height as an independent variable increases the possibility of the practical application of the proposed solutions using remote data sources.

scholarly journals Standing crops of dominant combretum species at three browsing levels in the Kruger National Park

Koedoe ◽  
1978 ◽  
Vol 21 (1) ◽  
Author(s):  
B.R. Dayton
Keyword(s):  
National Park ◽  
Correlation Coefficients ◽  
Kruger National Park ◽  
Total Biomass ◽  
Regression Equations ◽  
Stem Height ◽  
Basal Diameter ◽  
Independent Variable ◽  
Combretum Apiculatum ◽  
Different Levels

In red bushwillow veld near the Sand River in the Kruger National Park, Republic of South Africa, a determination was made of the standing crops of Combretum apiculatum and C. zeyheri at browsing levels delineated by the maximum feeding heights of impala (1,5 m), kudu (2,5 m) and giraffe (5,5 m). Using harvested sample trees, logarithmic or linear regression equations were generated which related basal diameter or stem height to biomass or percentage of total biomass at the different levels. Biomass was divided into two components: current shoots and wood plus bark. Regression forms and variables which produced the highest correlation coefficients changed with changes in species or browsing level, however, most equations were logarithmic with basal diameter as the independent variable.

The Effects of Superficial Heating before 1-MHz Ultrasound on Tissue Temperature

2003 ◽  
Vol 12 (2) ◽  
pp. 95-103 ◽  
Author(s):  
William R. Holcomb ◽  
Chris Blank
Keyword(s):  
Athletic Training ◽  
Repeated Measures ◽  
Outcome Measure ◽  
Tissue Temperature ◽  
Temperature Elevation ◽  
Main Outcome Measure ◽  
Cooling Period ◽  
Dependent Variables ◽  
Within Subjects ◽  
Independent Variable

Context:Ultrasound significantly raises tissue temperature, but the time of temperature elevation is short.Objective:To assess the effectiveness of superficial preheating on temperature elevation and decline when using ultrasound.Design:Within-subjects design to test the independent variable, treatment condition; repeated-measures ANOVAs to analyze the dependent variables, temperature elevation and decline.Setting:Athletic training laboratory.Intervention:Temperature at a depth of 3.75 cm was measured during ultrasound after superficial heating and with ultrasound alone.Subjects:10 healthy men.Main Outcome Measure:Temperature was recorded every 30 s during 15 min of ultrasound and for 15 min afterward.Results:Temperature elevation with ultrasound was significantly greater with preheating (4.0 ± 0.21 °C) than with ultrasound alone (3.0 ± 0.22 °C). Temperature decline was not significantly different between preheating and ultrasound alone.Conclusions:Superficial preheating significantly increases temperature elevation but has no effect on temperature decline during a 15-min cooling period.

Testing for Necessary and/or Sufficient Causation: Which Cases Are Relevant?

2002 ◽  
Vol 10 (2) ◽  
pp. 178-193 ◽  
Author(s):  
Jason Seawright
Keyword(s):  
Causal Inference ◽  
Marginal Distribution ◽  
Entire Population ◽  
Research Designs ◽  
Dependent Variables ◽  
Independent Variable

Previous researchers have argued that necessary and/or sufficient causes should be tested through research designs that consider only cases with limited combinations of scores on the independent and the dependent variables. I explore the utility for causal inference of the design proposed by these authors, as compared to an “All Cases Design.” I find that, if researchers define the population carefully and appropriately, each case in the population contributes to causal inference and is therefore useful. Previous authors reject this claim on the basis of a view that holds constant the marginal distribution of either the dependent or the independent variable across the working and the alternate hypotheses. I argue that this restriction is not generally appropriate, and hence, an analysis that samples from the entire population is logically defensible. I also argue that this design is more statistically efficient. A reanalysis of two well-known studies demonstrates that sampling from all cases in the relevant population produces greater confidence in the hypothesis than sampling only from cases that experience the outcome.

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