scholarly journals Preliminary evaluation for quality of dimension lumber in four common softwoods in Mongolia

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Murzabyek Sarkhad ◽  
Futoshi Ishiguri ◽  
Ikumi Nezu ◽  
Bayasaa Tumenjargal ◽  
Yusuke Takahashi ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Modulus Of Rupture ◽  
Preliminary Evaluation ◽  
Pinus Sibirica ◽  
Bending Properties ◽  
Picea Obovata ◽  
Dimension Lumber ◽  
Commercial Species ◽  
Characteristic Values

Abstract The quality of dimension lumber (2 by 4 lumber) was preliminarily investigated in four common Mongolian softwoods: Pinus sylvestris L., Pinus sibirica Du Tour, Picea obovata Ledeb., and Larix sibirica Ledeb. to produce high quality dimension lumber for structural use. In total 61, 39, 67, and 37 pieces of lumber were prepared for Pinus sylvestris, Pinus sibirica, Picea obovata, and L. sibirica, respectively. The lumber was visually graded and then tested in static bending to obtain the 5% lower tolerance limits at 75% confidence level (f0.05) of the modulus of elasticity (MOE) and the modulus of rupture (MOR). In addition, the effects of sawing patterns on bending properties were also analyzed. The f0.05 of the MOE and MOR were 4.75 GPa and 15.6 MPa, 3.39 GPa and 11.0 MPa, 3.78 GPa and 11.7 MPa, and 6.07 GPa and 22.3 MPa for Pinus sylvestris, Pinus sibirica, Picea obovata, and L. sibirica, respectively. These results suggested that with a few exceptions, characteristic values of MOR in the four common Mongolian softwoods resembled those in similar commercial species already used. In visual grading, over 80% of total lumber was assigned to select structural and No. 1 grades in Pinus sylvestris and Pinus sibirica, whereas approximately 40% of total lumber in L. sibirica was No. 3 and out of grades. Sawing patterns affected bending properties in Pinus sylvestris and L. sibirica, but did not affect Pinus sibirica and Picea obovata. Dynamic Young's modulus was significantly correlated with bending properties of dimension lumber for the four species. Based on the results, it was concluded that dimension lumber for structural use can be produced from the four common Mongolian softwoods.

scholarly journals THE STRUCTURE DYNAMICS OF POST-PYROGENIC COWBERRY PINE STANDS OF THE NORTHERN CIS-URAL (KOMI REPUBLIC)

ÈKOBIOTEH ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 627-633
Author(s):  
I.N. Kutyavin ◽  
◽  
A.V. Manov ◽  
A.V. Dymov ◽  
◽  
...  
Keyword(s):  
Species Composition ◽  
Pinus Sylvestris ◽  
Komi Republic ◽  
Forest Stand ◽  
Pinus Sibirica ◽  
Picea Obovata ◽  
Permanent Sample Plots ◽  
Stem Wood ◽  
Pine Stands ◽  
Prolonged Absence

Observations results of the development of cowberry pine stands on Pechoro-Ilychsky Reserve territory using the method of permanent sample plots are presented. It was established that pine stands, despite the active replenishment of their species composition with young coniferous trees, have a relatively stable supply of stem wood. It is noted that with a prolonged absence of fires, an active replenishment of the forest stand with new generations of Pinus sylvestris, Picea obovata and Pinus sibirica trees of different ages. It revealed that grassroots weak fires contribute jump regeneration of Picea obovata and Pinus sibirica that are gradually introduced into the pine stands.

Pengaruh Tekanan dan Penggunaan Conplast terhadap Sifat Mekanik Eternit dari Abu Cangkang Sawit

2016 ◽  
Vol 8 (15) ◽  
pp. 47-54
Author(s):  
Haspiadi Haspiadi
Keyword(s):  
Mechanical Properties ◽  
Oil Palm ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Density Values ◽  
Test Result

The purpose of this research is to know the influence of pressure and use of conplast against mechanical properties which are a Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) of plasterboard. The study is done because still low quality of plasterboard made from a mixture of ashes of oil-palm shell especially of the mechanical properties compared to the controls. The method of this reserach used variation of printed pressure and the addition of conplast. Test result is obtained that the highest value of Modulus of Elasticity (MOE) 90875.94 Kg/cm2, Modulus of Rupture (MOR) 61.16 Kg/cm2 and density values in generally good printed at the pressure 60 g/cm3 and the addition of conplast 25% as well as the composition of the ash of palm shell oil 40%: limestone 40%: cement 15%: fiber 5% and 300 mL of water. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh tekanan dan penggunaan conplast terhadap sifat mekanik yaitu kuat lentur dan keteguhan patah eternit berbahan dasar abu cangkang sawit. Penelitian ini dilakukan karena masi rendahnya mutu eternit berbahan campuran abu cangkang sawit dari bolier khususnya sifat mekanik dibandingkan dengan kontrol. Metode penelitian yang digunakan adalah dengan variasi tekanan cetak dan penambahan conplast. Hasil uji diperoleh bahwa kuat lentur tertinggi sebesar 90875,94 Kg/cm2 dan keteguhan patah sebesar 61,16 Kg/cm2, yang dicetak pada tekanan 60 g/cm3 dan penambahan conplast 25% dengan komposisi  abu cangkang sawit 40 %: kapur 40 % : semen 15 %: serat 5 % dan air 300 mL.Kata Kunci :  Abu cangkang sawit, conplast, kuat lentur, keteguhan patah.

Growth and management of mixed Pinus sylvestris - Quercus robur stands in Flanders, Belgium

1993 ◽  
Vol 58 ◽  
Author(s):  
D. Maddelein ◽  
J. Neirynck ◽  
G. Sioen
Keyword(s):  
Pinus Sylvestris ◽  
Natural Regeneration ◽  
Quercus Robur ◽  
Good Growth ◽  
Pedunculate Oak ◽  
Selection System ◽  
Management Options ◽  
Stand Management ◽  
Pine Stands

Mature  Scots pine (Pinus sylvestris  L.) stands are dominating large parts of the Flemish forest area. Broadleaved  species regenerate spontaneously under this pine canopy. This study studied  the growth and development of two planted pine stands with an older natural  regeneration, dominated by pedunculate oak (Quercus  robur L.), and discussed management options for  similar stands.     The results indicated a rather good growth of the stands, with current  annual increments of 5 m3.ha-1.yr-1. The pine overstorey is growing into valuable sawwood  dimensions, while the broadleaved understorey slowly grows into the  upperstorey. The quality of the regeneration is moderate but can be improved  by silvicultural measurements (pruning, early selection).     In both stands, an interesting (timber production, nature conservation)  admixture of secondary tree species is present in the regeneration. Stand  management is evolving from the classical clearcut system towards a  combination of a type of selection and group selection system.

scholarly journals Bending properties of dimension lumber produced from Siberian larch (Larix sibirica) in Mongolia

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Bayasaa Tumenjargal ◽  
Futoshi Ishiguri ◽  
Yusuke Takahashi ◽  
Ikumi Nezu ◽  
Bayartsetseg Baasan ◽  
...  
Keyword(s):  
Siberian Larch ◽  
Larix Sibirica ◽  
Bending Properties ◽  
Dimension Lumber

The Mae on Project: Using Acupuncture for Symptom Relief and Improved Quality of Life for People Living with Hiv and Aids in Rural Thailand

2010 ◽  
Vol 28 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Laura Louie ◽  
Nopporn Pathanapornpandh ◽  
Unchalee Pultajuk ◽  
Robert Kaplan ◽  
Ian Hodgson ◽  
...  
Keyword(s):  
Symptom Relief ◽  
Cost Effective ◽  
Integrated Approach ◽  
Hiv And Aids ◽  
People Living With Hiv ◽  
Preliminary Evaluation ◽  
Related Symptom ◽  
History Of ◽  
Living With Hiv

Acupuncture in combination with antiretroviral therapies is a potentially useful treatment for HIV-related symptom relief in resource-poor settings. Traditional Chinese medicine has a long history of being used to enhance immune function. In the setting of HIV, Chinese traditional medicine allows for symptom treatment without adding extra medications to a complex drug regime. This paper provides details of a project at Mae On Hospital in rural northern Thailand where allopathic/conventional treatments are used in tandem with acupuncture. A preliminary evaluation of the project suggests that an integrated approach to symptom relief is viewed positively by respondents receiving acupuncture, though further studies are required to confirm the association between acupuncture and symptom relief. The project also demonstrates the feasibility of developing a cost-effective acupuncture programme using local healthcare staff.

Comparison of various multivariate models to estimate structural properties by means of non-destructive techniques (NDTs) in Pinus sylvestris L. timber

Holzforschung ◽  
2019 ◽  
Vol 73 (4) ◽  
pp. 331-338
Author(s):  
Antonio Villasante ◽  
Guillermo Íñiguez-González ◽  
Lluis Puigdomenech
Keyword(s):  
Pinus Sylvestris ◽  
Linear Models ◽  
Longitudinal Vibration ◽  
Modulus Of Rupture ◽  
Coefficient Of Determination ◽  
Pullout Resistance ◽  
Density Prediction ◽  
Learning Software ◽  
Artificial Neural Network Ann ◽  
Non Destructive

AbstractThe predictability of modulus of elasticity (MOE), modulus of rupture (MOR) and density of 120 samples of Scots pine (Pinus sylvestrisL.) were investigated using various non-destructive variables (such as time of flight of stress wave, natural frequency of longitudinal vibration, penetration depth, pullout resistance, visual grading and concentrated knot diameter ratio), and based on multivariate algorithms, applying WEKA as machine learning software. The algorithms used were: multivariate linear regression (MLR), Gaussian, Lazy, artificial neural network (ANN), Rules and decision Tree. The models were quantified based on the root-mean-square error (RMSE) and the coefficient of determination (R2). To avoid model overfitting, the modeling was built and the results validated via the so-called 10-fold cross-validation. MLR with the “greedy method” for variable selection based on the Akaike information metric (MLRak) significantly reduced the RMSE of MOR and MOE compared to univariate linear regressions (ULR). However, this reduction was not significant for density prediction. The predictability of MLRak was not improved by any other of the tested algorithms. Specifically, non-linear models, such as multilayer perceptron, did not contribute any significant improvements over linear models. Finally, MLRak models were simplified by discarding the variables that produce the lowest RMSE increment. The resulted models could be even further simplified without significant RMSE increment.

Grade yields and wood properties of Norway spruce [Picea abies (L.) Karst.] from the Maritimes

1995 ◽  
Vol 71 (4) ◽  
pp. 473-478
Author(s):  
Y. H. Chui
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Wood Quality ◽  
Wood Properties ◽  
Bending Properties ◽  
Clear Wood ◽  
Comparative Information ◽  
Grade Yield

Norway spruce [Picea abies (L.) Karst.] is one of the major non-native softwood species in the Maritimes. A project was undertaken to evaluate the grade yields and mechanical properties of Norway spruce. The project also provided comparative information on the wood quality of two Norway spruce provenances from Germany and Poland. Four plantations were selected for the study with two of these plantations containing trees of known provenances. One plantation was mature and the other three were juvenile. In total, 530 pieces of lumber and the same number of matched small clear specimens were tested for bending properties. Prior to testing, the lumber was visually graded according to both British and Canadian specifications. Quality of lumber varied significantly between sites. Lumber from the Polish provenance had slightly better mechanical properties than that from trees of the German provenance. Compared with published information, the plantation-grown Norway spruce had lower clear wood bending properties and specific gravity than primary eastern Canadian spruce species and balsam fir, and natural Norway spruce grown in Europe. Key words: Norway spruce [Picea abies (L.) Karst.], wood quality, bending properties, grade yield

A preliminary evaluation of the associations among functional performance tasks and quality of life in obese and healthy weight youth

2018 ◽  
Vol 37 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Matthew S. Briggs ◽  
Sharon Bout-Tabaku ◽  
Jackie Buell ◽  
Susan White ◽  
Patricia F. Rosenstein ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Functional Performance ◽  
Preliminary Evaluation ◽  
Healthy Weight ◽  
Performance Tasks
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