scholarly journals The Influence of Freezing and Thawing Process on the Bending Moment Capacity of L-Shaped Heat-Treated Wood Dowel Joints

2021 ◽  
Vol 14(63) (2) ◽  
pp. 51-60
Author(s):  
Bogdan BEDELEAN ◽  
◽  
Răzvan COCIȘ ◽  
Keyword(s):  
Treated Wood ◽  
Bending Moment ◽  
Freezing And Thawing ◽  
Moment Capacity ◽  
Heat Treated ◽  
Wood Dowel ◽  
Significant Difference ◽  
Thawing Process ◽  
Ultimate Failure ◽  
One Way Anova

In this work, the influence of the freezing and thawing process on the bending moment capacity of L-shaped heat-treated wood dowel joints is analysed. The parts of the joints were made of heat-treated ash (Fraxinus excelsior) wood. Half of the analysed joints were randomly divided in two groups. One group was frozen and thawed in a climatic chamber and the other group was kept in laboratory environmental conditions. The bending moment capacity was calculated by means of ultimate failure load, which was experimentally obtained. One-way analysis of variance (One-way ANOVA) was applied to figure out if there is a significant difference between the analysed groups. Based on the obtained results, it was concluded that the freezing and thawing process did not significantly affect the strength of the L-shaped heat-treated wood dowel joints.

THE INFLUENCE OF THE NUMBER AND POSITION OF DOWELS ON THE BENDING MOMENT CAPACITY OF HEAT-TREATED WOOD DOWEL JOINTS

2021 ◽  
Vol 14(63) (1) ◽  
pp. 67-76
Author(s):  
Bogdan I. BEDELEAN ◽  
Iosif NECULĂEȘ ◽  
Cosmin G. SPÎRCHEZ ◽  
Sergiu RĂCĂȘAN
Keyword(s):  
Cross Section ◽  
Treated Wood ◽  
Bending Moment ◽  
Moment Capacity ◽  
Moment Arms ◽  
Heat Treated ◽  
Wood Dowel ◽  
Ultimate Failure ◽  
The Cross ◽  
The Moment

In this work, the influence of the number of dowels and the option to place the dowels in the cross section of part on the bending moment capacity of heat-treated wood dowel joints was analysed. The joints, which were made of heat-treated ash, were tested by means of a universal testing machine.The ultimate failure load and the moment arms were used to figure out the bending moment capacity of the joints loaded in compression or in tension. The number of dowels affected the tensile strength of the L-shaped heat-treated wood joints. The modality to place the dowels in the cross section of rail, namely, in collinearity or in a triangular shape, did not significantly affect the strength of the heat-treated wood dowel joints.

scholarly journals Comparison between artificial neural networks and response surface methodology to predict the bending moment capacity of heat-treated wood dowel joints

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5764-5775
Author(s):  
Sergiu Răcășan ◽  
Bogdan Bedelean ◽  
Sergiu Georgescu ◽  
Anca Maria Varodi
Keyword(s):  
Response Surface Methodology ◽  
Treated Wood ◽  
Bending Moment ◽  
Mean Square ◽  
Ann Model ◽  
Moment Capacity ◽  
Heat Treated ◽  
Wood Dowel ◽  
Ann Models ◽  
Rsm Model

The bending moment capacity of heat-treated wood dowel joints loaded in compression or tension was predicted via two artificial neural network (ANN) models. Additionally, a comparative study between similar models that were developed through response surface methodology (RSM) was performed. The joints were made of heat-treated ash (Fraxinus excelsior). The values of the ultimate failure load and the moment arms were recorded for each run via a universal testing machine. To develop the ANN models, the experimental data were randomly divided into three subsets, which were needed for the training, testing, and validation phases. The RSM models were obtained from the literature. The performances of the models were analyzed in terms of the correlation coefficient, coefficient of determination, root mean square error, mean square error, and mean absolute prediction error. A sensitivity analysis was also performed to observe potential changes in the results due to the uncertainty in the input variables. The ANN model better predicted the bending moment capacity of heat-treated wood dowel joints loaded in compression than the RSM model. In contrast, the RSM model predicted the bending moment capacity of joints loaded in tension more accurately than the ANN model.

scholarly journals Fracture Resistance of K3 Nickel-Titanium Files Made from Different Thermal Treatments

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
JinWook Choi ◽  
Soram Oh ◽  
Yu-Chan Kim ◽  
Kwang-Koo Jee ◽  
KeeYeon Kum ◽  
...  
Keyword(s):  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Torsional Angle ◽  
Thermal Treatments ◽  
Heat Treated ◽  
Significant Difference ◽  
Number Of Cycles ◽  
Torsional Fracture ◽  
One Way Anova ◽  
Angle Of Rotation

The purpose of this study was to compare fracture resistances of K3 nickel-titanium files made from different thermal treatments. K3 (SybronEndo, Orange, CA), K3XF (SybronEndo), and experimentally heat treated K3 (K3H) were used. For the cyclic fatigue test, the samples were rotated with up-and-down motion in the artificial canal with the curvature of 60 degrees until the fracture occurred. The number of cycles to fracture (NCF) was measured. For the torsional fracture test, the samples were tightly bound and rotated until the fracture occurred. Elastic modulus (EM), ultimate torsional strength (UTS), and angle of rotation to fracture (ARF) were measured. The results were statistically analyzed by one-way ANOVA. The NCF of K3H was higher than those of K3 and K3XF (P<0.05). The EM of K3XF and K3H was lower than that of K3 (P<0.05). There was no significant difference in UTS. The ARF of K3XF was higher than that of K3 (P<0.05). K3XF and K3H showed more flexibility than K3. The maximum torsional angle of K3XF was higher than that of K3, but there was no significant difference on the UTS in all three groups.

Factor VIII-Related Activities in Normal, Haemophilic and von Willebrand’s Disease Platelet Fractions

1978 ◽  
Vol 40 (02) ◽  
pp. 288-301 ◽  
Author(s):  
P Meucci ◽  
I R Peake ◽  
A L Bloom
Keyword(s):  
Factor Viii ◽  
Electrophoretic Mobility ◽  
Concanavalin A ◽  
Freezing And Thawing ◽  
Von Willebrand's Disease ◽  
Factor Viii Related Antigen ◽  
Von Willebrand’S Disease ◽  
Normal Plasma ◽  
Significant Difference ◽  
Ristocetin Cofactor

SummaryFactor VIII-related activities have been studied in platelet fractions in order to try to reconcile the conflicting findings of other workers, and to extend the studies. In platelets from 16 normal subjects procoagulant factor VIII was not detected. The amount of factor VIII-related antigen (FVIIIR: AG) in the cytosol per mg of protein was about twice that in the membrane fraction and about ten times that in the debris fraction. There was no significant difference between the amount of FVIIIR: AG and ristocetin cofactor (RistCof) activity in each fraction. The findings in haemophilic platelets were similar. In von Willebrand’s disease (vWd) one serverely affected patient had no detectable factor VIII related activities in any platelet fraction. In 5 patients with intermediate vWd results were normal. In a further 5, with more prolonged bleeding times, no FVIIIR: RistCof was detected in platelets, despite a normal amount of FVIIIR: AG in the cytosol and debris. The electrophoretic mobility of cytosol FVIIIR: AG was increased in all normals and patients, while that in the membrane and debris fractions had normal mobility. Cytosol FVIIIR: AG eluted later than normal FVIIIR: AG on gel filtration on Sepharose 2B, and also showed reduced antibody binding in an immunoradiometric assay. Precipitation of FVIIIR: AG by concanavalin A was incomplete in all platelet fractions from normals, and even more reduced in vWd platelet fractions. The results suggest the possibility of two types of platelet FVIIIR: AG.A factor VIII-related antigen was shown to be associated with normal washed platelets by immunofluorescence techniques (Bloom et al. 1973). Since then, several studies have been reported on the localisation of factor VIII related antigen (FVIIIR: AG), factor VIII procoagulant activity (FVIII: C) and factor VIII related ristocetin cofactor activity (FVIIIR: RistCof) within the platelets. Initially, Howard et al. (1974) indicated that FVIIIR: AG was firmly bound to the platelet membrane, and noted that in lysed platelets the level of FVIIIR: AG as measured by electroimmunodiffusion was higher than that in whole platelet suspensions. However, further studies by Nachman and Jaffe (1975) showed that FVIIIR: AG was also present to a considerable extent in the granules, and they detected none in the platelet cytosol. Bouma and colleagues (1975) were, however, able to find FVIIIR: AG and FVIIIR: RistCof in the cytosol upon freezing and thawing platelets. This FVIIIR: AG had an electrophoretic mobility comparable to that of normal plasma. They also noted that platelets which were air dried apparently had a granular FVIIIR:AG localisation by immunfluorescence; however, intact platelets in suspension did not stain by this method.Recently Ruggeri et al. (1977) and Sultan et al. (1977) have also found FVIIIR: AG in the cytosol, and the former authors reported it to have increased electrophoretic mobility when compared to normal plasma FVIIIR:AG. Results concerning the localisation of FVIIIR: AG in normal platelets have thus been conflicting. Similarly, in the few reports available concerning platelet FVIIIR: AG in von Willibrand’s disease variable results have also been obtained (Ruggeri et al. 1977, Howard et al. 1974, Shearn et al. 1974 and Bouma et al. 1975).In this study we report on the localisation of factor VIII-related activities in normal, haemophilic and von Willebrand’s disease platelets using available standard techniques as well as precipitation of FVIIIR: AG with the plant lectin concanavalin A, a procedure which has been shown to detect abnormal forms of FVIIIR:AG in certain types of von Willebrand’s disease (Peake and Bloom 1977).

Transplantation of coral fragment, Acropora formosa (Scleractinia)

2014 ◽  
pp. 1
Author(s):  
Hanny Tioho ◽  
Maykel A.J Karauwan
Keyword(s):  
Fragment Size ◽  
Observation Time ◽  
Minimum Size ◽  
Average Growth Rate ◽  
Average Growth ◽  
Significant Difference ◽  
Acropora Formosa ◽  
Survival And Growth ◽  
One Way Anova ◽  
Better Than

The minimum size of coral transplants, Acropora formosa, was assessed to support their survival and growth. For this, 150 coral fragments of different sizes (5, 10, 15 cm) were transplanted close to the donor colony. Their survivorship and growth were observed for 12 months. At the end of the observation time, 90% of 15 cm-transplanted coral fragments survived, while the others (10cm and 5 cm) did 86% and 82% respectively. The average growth rate of 5 cm-coral fragments was 0.860 cm/month, while 10 and 15 cm-fragments were 0.984 cm/month and 1.108 cm/month respectively. One-way ANOVA showed that there was significant difference (p<0.05) among the three (5, 10, 15 cm) transplant initial sizes in which the longest fragment size tended to survive longer than the smaller one.  However, the smaller transplants grew better than the bigger one, 10.318 cm/year (206%) for 5 cm-transplant, 11.803 cm/year (118%) for 10 cm-transplant, and 13.299 cm/year (89%) for 15 cm-transplant, respectively. Ukuran minimal fragmen karang Acropora formosa yang ditransplantasi diduga untuk mendukung ketahanan hidup dan pertumbuhannya. Untuk itu, 150 fragmen karang ditransplantasi ke lokasi yang berdekatan dengan koloni induknya.  Ketahanan hidup dan pertumbuhan semua fragmen karang yang ditransplantasi diamati selama 12 bulan.  Pada akhir pengamatan, 90% dari fragmen karang berukuran 15 cm yang ditransplantasi dapat bertahan hidup, sedangkan yang lainnya (ukuran 10 cm dan 5 cm) masing-masing sebesar 86% dan 82%.  Rata-rata laju pertumbuhan fragmen karang dengan ukuran awal 5 cm adalah 0,860 cm/bulan, sedangkan ukuran fragmen 10 dan 15 cm masing-masing adalah 0,984 cm/bulan and 1,108 cm/bulan. ANOVA satu arah menunjukkan adanya perbedaan yang nyata (p<0.05) antara ketiga ukuran fragmen yang berbeda, di mana ukuran fragmen karang yang lebih panjang cenderung mempunyai ketahanan hidup yang lebih baik. Namun demikian, ukuran transplant yang lebih kecil memiliki pertumbuhan lebih baik dibandingkan dengan ukuran yang lebih besar, yakni10,318 cm/tahun (206%) untuk transplant berukuran 5 cm, 11,803 cm/tahun (118%) untuk 10 cm, dan 13,299 cm/tahun (89%) untuk ukuran 15 cm.

Meta‐analysis of anti‐swelling efficiency (ASE) of heat‐treated wood

2021 ◽  
Author(s):  
Tianyi Zhan ◽  
Zhiting Liu ◽  
Hui Peng ◽  
Jiali Jiang ◽  
Yaoli Zhang ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Treated Wood ◽  
Heat Treated

scholarly journals Temperature-Dependent Creep Behavior and Quasi-Static Mechanical Properties of Heat-Treated Wood

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 968
Author(s):  
Dong Xing ◽  
Xinzhou Wang ◽  
Siqun Wang
Keyword(s):  
Mechanical Properties ◽  
Creep Behavior ◽  
Cell Walls ◽  
Treated Wood ◽  
Crosslinking Reaction ◽  
Depth Sensing ◽  
Temperature Dependent ◽  
Heat Treated ◽  
Static Mechanical ◽  
Static Mechanical Properties

In this paper, Berkovich depth-sensing indentation has been used to study the effects of the temperature-dependent quasi-static mechanical properties and creep deformation of heat-treated wood at temperatures from 20 °C to 180 °C. The characteristics of the load–depth curve, creep strain rate, creep compliance, and creep stress exponent of heat-treated wood are evaluated. The results showed that high temperature heat treatment improved the hardness of wood cell walls and reduced the creep rate of wood cell walls. This is mainly due to the improvement of the crystallinity of the cellulose, and the recondensation and crosslinking reaction of the lignocellulose structure. The Burgers model is well fitted to study the creep behavior of heat-treated wood cell walls under different temperatures.

Analysis of Support for Parents in Raising Children with Dyslexia

2020 ◽  
pp. 0192513X2094892
Author(s):  
Athira Amira Abd Rauf ◽  
Maizatul Akmar Ismail ◽  
Vimala Balakrishnan ◽  
Loh Sau Cheong ◽  
Novia Indriaty Admodisastro ◽  
...  
Keyword(s):  
Marital Status ◽  
Self Esteem ◽  
Peer To Peer ◽  
Government Support ◽  
Anova Analysis ◽  
Raising Children ◽  
The Social ◽  
Significant Difference ◽  
Different Types ◽  
One Way Anova

The parents of children with dyslexia often experience more parenting stress and depressive symptoms compared to other parents. Studies have shown that supporting and encouraging such parents help in reducing their frustrations, fear, anger, and low self-esteem towards their children. The purpose of this study was to identify and examine the different types of support needed by the parents of children with dyslexia and to explore the relationships between the required support with the parents’ marital status. Fifty questionnaires were distributed to the parents of children with dyslexia and analyzed. The findings showed that the type of support needed for parents of children with dyslexia could be grouped into social, peer-to-peer, financial, and government support. Furthermore, the analysis indicated that there were no significant differences between the social (p = 0.4014), peer-to-peer (p = 0.5020), and government (p = 0.7121) support with parents’ marital status. However, based on one-way ANOVA analysis, there was a significant difference found between the parents’ marital status and financial support (p = 0.0241). Accordingly, it is anticipated that the implication of this research could be used as a guide and a reference for supporting and encouraging parents of children with dyslexia and other learning disabilities.

Submarine Pipeline Installation JIP: Strength and Deformation Capacity of Pipes Passing Over the S-Lay Vessel Stinger

2006 ◽  
Author(s):  
Enrico Torselletti ◽  
Luigino Vitali ◽  
Erik Levold ◽  
Kim J. Mo̸rk
Keyword(s):  
Water Depth ◽  
Failure Modes ◽  
Bending Moment ◽  
External Pressure ◽  
Submarine Pipeline ◽  
Design Guideline ◽  
Moment Capacity ◽  
Sea Bottom ◽  
Major Vessel ◽  
Gas Fields

The development of deep water gas fields using trunklines to carry the gas to the markets is sometime limited by the feasibility/economics of the construction phase. In particular there is a market for using S-lay vessels in water depth larger than 1000m. The S-lay feasibility depends on the applicable tension at the tensioner which is a function of water depth, stinger length and stinger curvature (for given stinger length by its curvature). This means that, without major vessel up-grading and to avoid too long stingers that are prone to damages caused by environmental loads, the application of larger stinger curvatures than presently allowed by current regulations/state of the art is needed. The work presented in this paper is a result of the project “Development of a Design Guideline for Submarine Pipeline Installation” sponsored by STATOIL and HYDRO. The technical activities are performed in co-operation by DNV, STATOIL and SNAMPROGETTI. The scope of the project is to produce a LRFD (Load Resistant Factor Design) design guideline to be used in the definition and application of design criteria for the laying phase e.g. to S and J-lay methods/equipment. The guideline covers D/t from 15 to 45 and applied strains over the overbend in excess of 0.5%. This paper addresses the failure modes relevant for combined high curvatures/strains, axial, external pressure and local forces due to roller over the stinger of an S-lay vessel and to sea bottom contacts, particularly: • Residual pipe ovality after laying, • Maximum strain and bending moment capacity. Analytical equations are proposed in accordance with DNV OS F101 philosophy and design format.

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