scholarly journals Edge screw withdrawal resistance in conventional particleboard and OSB: Influence of the particles type

2007 ◽  
pp. 109-117
Author(s):  
Jovan Miljkovic ◽  
Mladjan Popovic ◽  
Milanka Djiporovic-Momcilovic ◽  
Ivana Gavrilovic-Grmusa
Keyword(s):  
Oriented Strand Board ◽  
Layer Structure ◽  
Middle Layer ◽  
Root Diameter ◽  
Mean Values ◽  
Pilot Hole ◽  
Wood Particles ◽  
Screw Withdrawal ◽  
Insight Into

This research was based on presumption that the changes in size and shape of wood particles are expected to have certain impact on the particleboard quality in general. Since the conventional particleboard (PB) and oriented strand board (OSB) were built of the quite diverse wood particles, they present interesting specimens in the comparison tests. In this work, the influence of the wood particles type on the edge screw holding performance of conventional particleboard and OSB was investigated. Those tests were obtained with the screw diameters of 4.0 mm, 4.5 mm and 5 mm. Depth of embedment was 30 mm for all tests and with the pilot-hole diameter kept in the range of 80-90% in respect of the screw root diameter. Additional tests of the thickness density profile and tensile strength perpendicular to the surface of the board were conducted. Since the middle layer structure of the particleboard embeds the screw body, both mentioned parameters are considered important in the aspect of the quality of the edge screw holding performance. In order to have further insight into the conformation of the middle layer the image survey was obtained on the split board section presenting the surface of the middle layer. Significant differences in the SWR performance of OSB and PB was recorded at all screw diameters. For the screw withdrawal tests parameters OSB samples showed 56-73% superior mean values then conventional PB. On the other hand, the OSB showed wider dispersions of measured withdrawal forces at all screw diameters, which might present some of the problems in certain engineering and project calculations.

scholarly journals The improvement of the edge screw connection in OSB and conventional particleboard

2006 ◽  
pp. 257-266
Author(s):  
Mladjan Popovic ◽  
Milanka Djiporovic-Momcilovic ◽  
Jovan Miljkovic ◽  
Ivana Gavrilovic-Grmusa
Keyword(s):  
Oriented Strand Board ◽  
Wood Flour ◽  
Pilot Hole ◽  
Positive Effects ◽  
Nominal Thickness ◽  
Screw Withdrawal ◽  
Type 3 ◽  
Adhesive Type

This work presents the method for improvement of direct screw connection performance in conventional particleboard (PB) and oriented strand board (OSB). It is conceived on adhesive insertion into the pilot hole prior to embedment of the screw. The tests were carried out on the PB and OSB, both presenting interior boards and with the same nominal thickness of 18 mm. Particleboard screws of the 5 mm in diameter were inserted in the edge of the board. Pilot hole diameters were 2,5 mm and 3,0 mm and the depth of embedment was 30 mm for all tests. The chosen PVAc adhesive (type 3) with the addition of wood flour as consolidator in the range from 3-10% was inserted into pilot-hole. Tests were also obtained after consequent reassembly of the screw connection in order to examine the ratio of loss in withdrawal forces in such case. It was found that the insertion of PVAc adhesive into the pilot hole and the addition of wood flour have the positive effects on the screw withdrawal force in the tested boards.

scholarly journals EVALUATIOM OF PHYSICAL AND MECHANICAL PROPERTIES OF PARTICLEBOARD PRODUCED FROM WOOD OF Cupressus torulosa IN MIXTURE WITH Pinus taeda

FLORESTA ◽  
2020 ◽  
Vol 50 (3) ◽  
pp. 1478
Author(s):  
Setsuo Iwakiri ◽  
Rosilani Trianoski ◽  
Amanda Leite Da Silva ◽  
Angela Maria Stüpp ◽  
Bruna Mulinari Cabral ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Formaldehyde Resin ◽  
Wood Particles ◽  
Normative Requirements ◽  
Nominal Density ◽  
Cupressus Torulosa ◽  
Screw Withdrawal

The objective of this work was to evaluate the quality of particleboard produced with 100% of wood of Cupressus torulosa and in different mixing proportions with Pinus taeda. The experimental panels were produced with wood particles of Cupressus torulosa/Pinus taeda, in proportions of 100/0%, 80/20%, 60/40%, 40/60%, 20/80% and 0/100%, totaling six treatments. The panels were produced with nominal density of 0.75g/cm³, 8% urea-formaldehyde resin and 1% paraffin emulsion. The quality of the panels was evaluated by water absorption and swelling thickness 2 and 24 hours, static bending (MOE and MOR), perpendicular tension (internal bonding) and screw withdrawal. The comparative evaluations of the results of this research, with the Pinus taeda, others species referenced in the literature, and normative requirements of EN 312-2003 for commercial panels, indicated great potential of the wood of Cupressus torulosa for the particleboard production.

Attitudes of Elderly People in the South Moravian Region to Further Education

2014 ◽  
Vol 4 (2) ◽  
pp. 54-78
Author(s):  
Petr Adamec ◽  
Marián Svoboda
Keyword(s):  
Quality Of Life ◽  
Elderly People ◽  
Further Education ◽  
The South ◽  
The Third ◽  
Interesting Insight ◽  
Survey Results ◽  
Insight Into ◽  
Demographic Features

This paper deals with the results of sociological survey focused on identification of the attitudes of elderly people to further education. The research was carried out in September 2010. Experience of elderly people with further education, their readiness (determination) for further education as well as their motivation and barriers in further education were also subjects of this research. Detecting elderly population’s awareness of universities of the third age and finding out their further education preferences were an integral part of the research. Research sample consisted of citizens over 55 years living in the South Moravian region. The survey results are structured by socio-demographic features e.g.: age, sex, educational attainment etc. and provide an interesting insight into the attitudes of the target group to one of the activities that contributes to improvement of their quality of life.

scholarly journals Comparisons among rainbow trout, Oncorhynchus mykiss, populations of maternal transcript profile associated with egg viability

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gregory M. Weber ◽  
Jill Birkett ◽  
Kyle Martin ◽  
Doug Dixon ◽  
Guangtu Gao ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Egg Quality ◽  
Transcript Abundance ◽  
Differentially Expressed ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Analysis Group ◽  
Maternal Transcripts ◽  
Single Batch ◽  
Insight Into

Abstract Background Transcription is arrested in the late stage oocyte and therefore the maternal transcriptome stored in the oocyte provides nearly all the mRNA required for oocyte maturation, fertilization, and early cleavage of the embryo. The transcriptome of the unfertilized egg, therefore, has potential to provide markers for predictors of egg quality and diagnosing problems with embryo production encountered by fish hatcheries. Although levels of specific transcripts have been shown to associate with measures of egg quality, these differentially expressed genes (DEGs) have not been consistent among studies. The present study compares differences in select transcripts among unfertilized rainbow trout eggs of different quality based on eyeing rate, among 2 year classes of the same line (A1, A2) and a population from a different hatchery (B). The study compared 65 transcripts previously reported to be differentially expressed with egg quality in rainbow trout. Results There were 32 transcripts identified as DEGs among the three groups by regression analysis. Group A1 had the most DEGs, 26; A2 had 15, 14 of which were shared with A1; and B had 12, 7 of which overlapped with A1 or A2. Six transcripts were found in all three groups, dcaf11, impa2, mrpl39_like, senp7, tfip11 and uchl1. Conclusions Our results confirmed maternal transcripts found to be differentially expressed between low- and high-quality eggs in one population of rainbow trout can often be found to overlap with DEGs in other populations. The transcripts differentially expressed with egg quality remain consistent among year classes of the same line. Greater similarity in dysregulated transcripts within year classes of the same line than among lines suggests patterns of transcriptome dysregulation may provide insight into causes of decreased viability within a hatchery population. Although many DEGs were identified, for each of the genes there is considerable variability in transcript abundance among eggs of similar quality and low correlations between transcript abundance and eyeing rate, making it highly improbable to predict the quality of a single batch of eggs based on transcript abundance of just a few genes.

scholarly journals The Impact of Post-Manufacture Treatments on the Surface Characteristics Important for Finishing of OSB and Particleboard

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Antonio Copak ◽  
Vlatka Jirouš-Rajković ◽  
Nikola Španić ◽  
Josip Miklečić
Keyword(s):  
Water Vapour ◽  
Oriented Strand Board ◽  
Construction Material ◽  
Surface Characteristics ◽  
Surface Treatments ◽  
Factors Affecting ◽  
Treatment Conditions ◽  
Water Vapour Absorption ◽  
The Impact

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.

A Study on the Mineral Depletion of the Foods Available to us as a Nation over the Period 1940 to 1991

2003 ◽  
Vol 17 (2) ◽  
pp. 85-115 ◽  
Author(s):  
David Thomas
Keyword(s):  
Mineral Content ◽  
Dietary Habits ◽  
Medical Research Council ◽  
Significant Loss ◽  
King's College ◽  
Compare And Contrast ◽  
Insight Into ◽  
Mineral Constituents ◽  
Mineral Depletion

In 1927 a study at King's College, University of London, of the chemical composition of foods was initiated by Dr McCance to assist with diabetic dietary guidance. The study evolved and was then broadened to determine all the important organic and mineral constituents of foods, it was financed by the Medical Research Council and eventually published in 1940. Over the next 51 years subsequent editions reflected changing national dietary habits and food laws as well as advances in analytical procedures. The most recent (5th Edition) published in 1991 has comprehensively analysed 14 different categories of foods and beverages. In order to provide some insight into any variation in the quality of the foods available to us as a nation between 1940 and 1991 it was possible to compare and contrast the mineral content of 27 varieties of vegetable, 17 varieties of fruit, 10 cuts of meat and some milk and cheese products. The results demonstrate that there has been a significant loss of minerals and trace elements in these foods over that period of time. It is suggested that the results of this study cannot be taken in isolation from recent dietary, environmental and disease trends. These trends are briefly mentioned and suggestions are made as to how the deterioration in the micronutrient quality of our food intake may be arrested and reversed.

scholarly journals Probing of the internal damage morphology in multilayered high-temperature superconducting wires

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
You-He Zhou ◽  
Cong Liu ◽  
Lei Shen ◽  
Xingyi Zhang
Keyword(s):  
Magnetic Flux ◽  
Layer Structure ◽  
Extreme Environment ◽  
Uniaxial Tensile ◽  
Internal Damage ◽  
Amorphous Phases ◽  
Superconducting Wires ◽  
Mechanical Quality ◽  
Loading System

AbstractThe second generation HTS wires have been used in many superconducting components of electrical engineering after they were fabricated. New challenge what we face to is how the damages occur in such wires with multi-layer structure under both mechanical and extreme environment, which also dominates their quality. In this work, a macroscale technique combined a real-time magneto-optical imaging with a cryogenic uniaxial-tensile loading system was established to investigate the damage behavior accompanied with magnetic flux evolution. Under a low speed of tensile strain, it was found that the local magnetic flux moves gradually to form intermittent multi-stack spindle penetrations, which corresponds to the cracks initiated from substrate and extend along both tape thickness and width directions, where the amorphous phases at the tip of cracks were also observed. The obtained results reveal the mechanism of damage formation and provide a potential orientation for improving mechanical quality of these wires.

scholarly journals Dialogical research to open up new narrative patterns among young women living with severe anxiety

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
L Cantarero Arevalo ◽  
S Fejfer Olsen
Keyword(s):  
Young Women ◽  
Population Group ◽  
Patient Experiences ◽  
Constructivist Approach ◽  
Patient’S Perspective ◽  
Healthcare Needs ◽  
Narrative Patterns ◽  
Severe Anxiety ◽  
Insight Into

Abstract Background 16,889 new cases of severe anxiety (SA) were diagnosed in Denmark in 2019. Incidence rate is highest among 16 to 24 year-old women, a population group with 64% risk of being diagnosed with SA. Experiences of stigma and shame are common among this group, affecting negatively their quality of life and opportunity to recover. The aim is 1) to gain insight into the digital narratives young women with SA share through social networking websites, and 2) to open up the possibility to develop new narrative patterns using dialogical research as a method rooted in Bakhtin (1895-1975) and further developed by Frank (2005). Methods Netnography of four large Facebook groups focused on anxiety was used to gain insight into the patients' narratives and to build guiding themes for the off-line dialogical interviews (DI). Biographical narrative patterns were analyzed in light of a narrative-constructivist approach. Participants were invited to sign an informed consent prior to the DI and received ample information about the project aims and their rights. Results 8 young women diagnosed with SA participated in the off-line DI. They had experienced stress, loss, betrayal or violation against them prior to the trigger of SA. All had constructed a narrative that explained why they were suffering from SA. Patient experiences were dominated by the struggle to control intrusive thoughts and to live in a threatening world. Some felt stigmatized and tried to hide their condition from colleagues, friends and family. They had different preferences regarding healthcare needs and were active in their search for alternative ways to cope with SA. Conclusions Participants perceived DI as beneficial. It thus has the potential to not only explore the patient's perspective in depth, but also serve as therapy during the process of inquiry. Key messages Dialogical research has the potential to not only explore the patient’s perspective in depth, but also serve as therapy during the process of inquiry. Young women suffering with severe anxiety experience shame and stigma, which worsen their condiction and hinder their opportunity to recover.

scholarly journals The Quality of Statistical Reporting and Data Presentation in Predatory Dental Journals Was Lower Than in Non-Predatory Journals

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 468
Author(s):  
Pentti Nieminen ◽  
Sergio E. Uribe
Keyword(s):  
Open Access ◽  
Peer Review ◽  
Scientific Journals ◽  
Mean Values ◽  
Data Presentation ◽  
Predatory Journals ◽  
Study Results ◽  
The Mean ◽  
Highly Cited

Proper peer review and quality of published articles are often regarded as signs of reliable scientific journals. The aim of this study was to compare whether the quality of statistical reporting and data presentation differs among articles published in ‘predatory dental journals’ and in other dental journals. We evaluated 50 articles published in ‘predatory open access (OA) journals’ and 100 clinical trials published in legitimate dental journals between 2019 and 2020. The quality of statistical reporting and data presentation of each paper was assessed on a scale from 0 (poor) to 10 (high). The mean (SD) quality score of the statistical reporting and data presentation was 2.5 (1.4) for the predatory OA journals, 4.8 (1.8) for the legitimate OA journals, and 5.6 (1.8) for the more visible dental journals. The mean values differed significantly (p < 0.001). The quality of statistical reporting of clinical studies published in predatory journals was found to be lower than in open access and highly cited journals. This difference in quality is a wake-up call to consume study results critically. Poor statistical reporting indicates wider general lower quality in publications where the authors and journals are less likely to be critiqued by peer review.

scholarly journals Treatment benefit among migraine patients taking fremanezumab: results from a post hoc responder analysis of two placebo-controlled trials

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Stephen D. Silberstein ◽  
Joshua M. Cohen ◽  
Ronghua Yang ◽  
Sanjay K. Gandhi ◽  
Evelyn Du ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Medication Use ◽  
Two Phase ◽  
Double Blind ◽  
Treatment Benefit ◽  
Mean Values ◽  
Treatment Benefits ◽  
Acute Headache ◽  
Post Hoc ◽  
Insight Into

Abstract Background Monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) pathway, including the fully humanized monoclonal antibody (IgG2Δa) fremanezumab, have demonstrated safety and efficacy for migraine prevention. Clinical trials include responders and nonresponders; efficacy outcomes describe mean values across both groups and thus provide little insight into the clinical benefit in responders. Clinicians and their patients want to understand the extent of clinical improvement in patients who respond. This post hoc analysis of fremanezumab treatment attempts to answer this question: what is the benefit in subjects who responded to treatment during the two, phase 3 HALO clinical trials? Methods We included subjects with episodic migraine (EM) or chronic migraine (CM) who received fremanezumab quarterly (675 mg/placebo/placebo) or monthly (EM: 225 mg/225 mg/225 mg; CM: 675 mg/225 mg/225 mg) during the 12-week randomized, double-blind, placebo-controlled HALO EM and HALO CM clinical trials. EM and CM responders were defined as participants with a reduction of ≥ 2 or ≥ 4 monthly migraine days, respectively. Treatment benefits evaluated included reductions in monthly migraine days, acute headache medication use, and headache-related disability, and changes in health-related quality of life (HRQoL). Results Overall, 857 participants from the HALO trials were identified as responders (EM: 429 [73.8%]; CM: 428 [56.7%]). Reductions in the monthly average number of migraine days were greater among EM (quarterly: 5.4 days; monthly: 5.5 days) and CM (quarterly: 8.7 days; monthly: 9.1 days) responders compared with the overall population. The proportion of participants achieving ≥ 50% reduction in the average monthly number of migraine days was also greater in responders (EM: quarterly, 59.8%; monthly, 63.7%; CM: quarterly, 52.8%; monthly, 59.0%) than in the overall population. Greater reductions in the average number of days of acute headache medication use, greater reductions in headache-related disability scores, and larger improvements in HRQoL were observed among EM and CM responders compared with the overall populations. Conclusions Fremanezumab responders achieved clinically meaningful improvements in all outcomes. The magnitude of improvements with fremanezumab across efficacy outcomes was far greater in responders than in the overall trial population, providing insight into expected treatment benefits in participants who respond to fremanezumab in clinical practice. Trial registration ClinicalTrials.gov identifiers: NCT02629861 (HALO EM) and NCT02621931 (HALO CM).

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