Development of poplar glued–laminated timber. I: Tensile strength and stiffness of poplar laminating stock

1986 ◽  
Vol 13 (4) ◽  
pp. 445-459 ◽  
Author(s):  
M. M. Lepper ◽  
F. J. Keenan
Keyword(s):  
Tensile Strength ◽  
Volume Effect ◽  
The Other ◽  
Regression Analyses ◽  
Frequency Data ◽  
Glulam Beam ◽  
Full Size ◽  
Glued Laminated Timber ◽  
Strength And Stiffness ◽  
General Slope

The tensile strength and stiffness of 263 full-size pieces of 38 × 80 mm in-grade poplar lumber from two mills in Ontario were determined. Prior to testing, complete maps of all grade-related defects in each piece were made; these defects included general slope of grain, centre knots, and edge knots. Specific gravity and moisture content were also recorded for each piece. After testing, the defects that triggered each piece's failure were noted. This information led, through regression analyses and the assumption of a Weibull distribution, to models for tensile strength and stiffness. The models were developed for the pieces from one mill and were tested against the results obtained from pieces from the other mill; agreement was very good. The knot frequency and slope frequency data were used in a modified form of the Foschi and Barrett glulam beam simulation model to predict the fifth fractile value of a population of poplar glulam beams. Taking the volume effect into account, the predicted beam strengths and stiffnesses are close to those of glulam beams of stress grade 20f–E.

scholarly journals Effects of water absorption on the mechanical properties of hybrid natural fibre/phenol formaldehyde composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sekar Sanjeevi ◽  
Vigneshwaran Shanmugam ◽  
Suresh Kumar ◽  
Velmurugan Ganesan ◽  
Gabriel Sas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Water Absorption ◽  
Hybrid Composites ◽  
Phenol Formaldehyde ◽  
Natural Fibre ◽  
The Other ◽  
Fibre Reinforcement ◽  
Dry Conditions

AbstractThis investigation is carried out to understand the effects of water absorption on the mechanical properties of hybrid phenol formaldehyde (PF) composite fabricated with Areca Fine Fibres (AFFs) and Calotropis Gigantea Fibre (CGF). Hybrid CGF/AFF/PF composites were manufactured using the hand layup technique at varying weight percentages of fibre reinforcement (25, 35 and 45%). Hybrid composite having 35 wt.% showed better mechanical properties (tensile strength ca. 59 MPa, flexural strength ca. 73 MPa and impact strength 1.43 kJ/m2) under wet and dry conditions as compared to the other hybrid composites. In general, the inclusion of the fibres enhanced the mechanical properties of neat PF. Increase in the fibre content increased the water absorption, however, after 120 h of immersion, all the composites attained an equilibrium state.

Proverbial homogeneity: A cross-linguistic examination of Korean and Indonesian

2014 ◽  
Vol 16 (1) ◽  
pp. 63-81
Author(s):  
Sang-Oak Lee
Keyword(s):  
The Other ◽  
Frequency Data ◽  
Corpus Linguistic ◽  
Cultural Life ◽  
Frequency Structure ◽  
Other Hand ◽  
The Last Two Millennia

This study explores the use of keywords in proverbs in Korean, English, Chinese, and Indonesian. The study applies the traditional corpus linguistic tools of frequency and ranking to the keywords found in proverbs in an attempt to characterize the proverbs of these languages. The frequency data show that English proverbs are dominated by abstract keywords like “love, God, age, foolishness, wisdom, poverty, good, evil, and truth.” On the other hand, Chinese proverbs are dominated by more “action oriented” and “pragmatic concern” keywords such as “heart, time, talk/say, act/do, words, method, and knowledge,” showing a clear divergence from the frequency structure of English proverb keywords. Surprisingly, Korean proverb keywords, just like the English keywords, are also found to share very little in common with Chinese, a longstanding neighbor which has strongly influenced the cultural life of Korea over the last two millennia. Instead, the data show that the proverb keyword structure most resembles that of Indonesian, both having material/physical terms dominating the keywords and both sharing three common top-ranking keywords: water, dog, and cow.

Was This in Your Statistics Textbook? IV. Frequency Data

1989 ◽  
Vol 25 (1) ◽  
pp. 11-25
Author(s):  
D. J. Finney
Keyword(s):  
Statistical Analysis ◽  
Contingency Tables ◽  
The Other ◽  
Frequency Data ◽  
Significance Tests ◽  
Test Statistic ◽  
Jumping To Conclusions ◽  
Proper Role ◽  
Measure Of Association

SUMMARYObservations that are frequencies rather than measurements often call for special types of statistical analysis. This paper comments on circumstances in which methods for one type of data can sensibly be used for the other. A section on two-way contingency tables emphasizes the proper role of χ2 a test statistic but not a measure of association; it mentions the distinction between one-tail and two-tail significance tests and reminds the reader of dangers. Multiway tables bring new complications, and the problems of interactions when additional classificatory factors are explicit or hidden are discussed at some length. A brief outline attempts to show how probit, logit, and similar techniques are related to the analysis of contingency tables. Finally, three unusual examples are described as illustrations of the care that is needed to avoid jumping to conclusions on how frequency data should be analysed.

Paranormal Belief, Experience, and the Keirsey Temperament Sorter

2000 ◽  
Vol 86 (3_part_2) ◽  
pp. 1104-1106
Author(s):  
Jezz Fox ◽  
Carl Williams
Keyword(s):  
College Students ◽  
Multiple Regression ◽  
The Other ◽  
Minor Role ◽  
Regression Analyses ◽  
Keirsey Temperament Sorter ◽  
Paranormal Belief ◽  
Anomalous Experience ◽  
A Minor ◽  
Paranormal Experience

121 college students completed the Anomalous Experience Inventory and the Keirsey Temperament Sorter. Multiple regression analyses provided significant models predicting both Paranormal Experience and Belief; the main predictors were the other subscales of the Anomalous Experience Inventory with the Keirsey variables playing only a minor role.

scholarly journals THE ANALYSIS OF OIL CONTENT IN SEDIMENT AND COMMUNITY STRUCTURE OF MACROZOOBENTHOS IN BELAWAN WATERS OF MEDAN CITY, NORTH SUMATERA PROVINCE

2020 ◽  
Vol 3 (2) ◽  
pp. 167-178
Author(s):  
Doli Juna Setia Tanjung ◽  
Bintal Amin ◽  
Syafruddin Nasution
Keyword(s):  
Community Structure ◽  
Linear Regression ◽  
Oil Content ◽  
Diversity Index ◽  
The Other ◽  
Regression Analyses ◽  
Simple Linear Regression ◽  
Dominance Index ◽  
Ocypode Quadrata ◽  
Evenness Index

This research was conducted in March 2019 to determine the oil content in sediment, it’s community structure of macrozoobenthos and it’s a relationship in Belawan Waters of Medan City, North Sumatera. Four sampling stations with five replications in each station were surveyed. The results showed that the average oil content in sediments exceeded the threshold had set by the National Academy of Science. Macrozoobenthos found consists of Ocypode quadrata, Scyla serrate, Rotun dicauda, Penaeus sp, Murex tribulus, and Nassarius olivaccus. The highest abundance was in Station 3 and the lowest was in Station 2. The diversity index in each station was generally very low. Dominance Index in Station 4 was medium, whilst the other stations were high. Evenness index showed in Station 3 and 4 were in high population, Station 1 was in medium population and Station 2 was in low population. Simple linear regression analyses between oil content in sediment with community structure of macrozoobenthos indicated negative correlation ( Y = 10,5-0,0001x , R2 = 0,0004 and r = 0,02 ) which indicated that the higher the oil content, the lower the macrozoobenthos abundance in sediment.

Development of tensile strength in compatible and incompatible sweet cherry graftings

2005 ◽  
Vol 83 (2) ◽  
pp. 202-210 ◽  
Author(s):  
Bjarne Hjelmsted Pedersen
Keyword(s):  
Tensile Strength ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
The Self ◽  
The Other ◽  
Preliminary Work ◽  
Cherry Rootstocks ◽  
Sweet Cherry Cultivars ◽  
Prunus Avium L

The tensile strengths of graftings between three selected sweet cherry cultivars and five selected cherry rootstocks were determined with an Instron instrument 6, 12, and 18 weeks after grafting and compared with the tensile strength of self-grafted rootstocks and graftings of rootstocks used as scions. The combination of sweet cherry cultivars and rootstocks was selected to provide a range of compatibility based on preliminary work. The tensile strengths of sweet cherry cultivars grafted on different rootstocks never exceeded the tensile strengths of the self-grafted rootstocks. Rootstocks grafted as scions on Prunus avium L. rootstocks and self-grafted rootstocks produced some of the strongest unions tested and also produced union strength much faster than any of the other combinations. The degree of compatibility was quantified and results indicated that if this value was below 0.2, measured 18 weeks after grafting, it corresponded to combinations with major risks of delayed incompatibility.Key words: tensile strength, grafting, compatibility, sweet cherry, Prunus avium.

Bacterial Cellulose Reinforced Flax Fibre Composites: Effect of Nanocellulose Loading on Composite Properties

2015 ◽  
Vol 825-826 ◽  
pp. 1063-1067
Author(s):  
Marta Fortea-Verdejo ◽  
Elias Bumbaris ◽  
Koon Yang Lee ◽  
Alexander Bismarck
Keyword(s):  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Flax Fibre ◽  
The Other ◽  
Cellulose Content ◽  
Polypropylene Composites ◽  
Flax Fibres ◽  
Paper Making ◽  
Fibre Composites ◽  
Composite Properties

Loose hierarchical flax fibres/polypropylene composites were manufactured in a simple way based on a paper-making process in order to include nanocellulose and allow the hornification of the nanofibres in a controlled manner. The effect of flax fibre content on the flax/polypropylene composites and the influence of nanocellulose on the properties of these composites are discussed. By increasing the flax content a slight decrease of the tensile strength and an increase of the Young´s modulus were observed. On the other hand, no significant effect was noticed when increasing the bacterial cellulose content in the composites.

scholarly journals The Chi-Square test: a frequency data based statistical device

2015 ◽  
Vol 3 (3) ◽  
pp. 53-55 ◽  
Author(s):  
Ashok Kumar
Keyword(s):  
Significant Role ◽  
Statistical Significance ◽  
The Other ◽  
Frequency Data ◽  
Chi Square ◽  
Medical Researchers ◽  
Chi Square Test ◽  
Control And Eradication

“Cause Effect” relationships are very important and play a most vital and significant role in medical researchers to reveal efficacy of medication as preventive and curative measures towards control and eradication of various diseases and morbidity factors. The present paper, in this direction is an attempt to highlight the main applicability of - test ( chi- square test ) ; a most appropriate statistical device in testing statistical significance of the above mentioned relationships in studying impact of one on the other ; supplemented by a few citations thereof.

A comparison of fibre deformations from mill like and laboratory kraft cooking of softwood

2014 ◽  
Vol 29 (2) ◽  
pp. 211-217
Author(s):  
Lennart Salmén ◽  
Joanna Hornatowska
Keyword(s):  
Tensile Strength ◽  
Unsolved Problem ◽  
The Other ◽  
Fibre Strength ◽  
Mechanical Forces ◽  
Lower Strength ◽  
Fibre Properties ◽  
Kraft Cooking ◽  
Pulp Strength ◽  
Fibre Shape

Abstract The fact that industrial pulps have a lower strength than their corresponding laboratory pulps is an unsolved problem affecting in various ways the potential fibre utilisation in different mills. The loss of pulp strength has to a great extent been attributed to changes at the fibre level. In order to clarify in what way changes in fibre properties contribute to the strength losses, cooking experiments were conducted using a laboratory batch digester in which mechanical forces may be introduced. Fibre properties, i.e. fibre structure and fibre strength, of laboratory-made pulps were compared with those of an industrial pulp. It was concluded that two essentially different mechanisms may be identified; one related to the transverse fibre shape, the other to fibre damage. The latter is manifested as lower rewetted zero-span strength which reduces tear resistance and tensile strength of the pulp. The former is a collapse of the fibre, reducing the lumen area and resulting in a pulp with lower water-retaining capacity, given sheets of lower density and a pulp that has to be beaten to a higher degree to reach the desired bonding and the desired tensile strength.

Analysis, simulation, and implementation of a human-inspired pole climbing robot

Robotica ◽  
2011 ◽  
Vol 30 (2) ◽  
pp. 279-287 ◽  
Author(s):  
A. Sadeghi ◽  
H. Moradi ◽  
M. Nili Ahmadabadi
Keyword(s):  
Static Analysis ◽  
Full Scale ◽  
The Other ◽  
Light Weight ◽  
Simple Design ◽  
Climbing Robot ◽  
Full Size ◽  
Control Light ◽  
The Stability ◽  
Novel Design

SUMMARYIn this paper, we present the design, static analysis, simulation, and implementation of a novel design for a naturally stable climbing robot that has been inspired from human pole/tree climbers. The other benefits of this robot, besides being naturally stable, are its simple design, ease of control, light weight, simple mechanism, and fast climbing speed. The robot consists of three wheels, two free and one active wheel, which enable the robot to climb or descend poles. The free wheels are almost frictionless, while the active wheel has enough friction to be able to apply force on the pole for stable climbing or descending. The wheels are designed in V-shape such that the robot can compensate for misplacements eliminating possible detachment from poles. Although the robot can operate with a single free wheel, however, an extra free wheel is added to increase the stability and safety of the robot. In this paper, the static analysis of the robot is presented and the robot is simulated. Furthermore, the robot is actually implemented and successfully tested in two sizes, a small size and a big/full size. The full-scale prototype has been equipped with washing and inspection tools and tested washing actual street lights. The results show the unique characteristics of this robot that make it more stable if more weight is carried.

Sign in / Sign up

Export Citation Format

Share Document