Properties of Plywood Made from Perforated Veneers

The paper is focused on the bending properties of beech plywood made from veneers with perforations. The modification of the plywood was done by the targeted perforations in veneers used. The perforations were rectangular in shape 5 × 30 mm. There was a gap of 10 mm between the perforations (in each direction) and the perforations in the individual rows were shifted by 10 mm relative to each other. Two structures of lightweight plywood were investigated: sheathed (lightweight type 1) with perforated inner layers sheathed with solid veneer and perforated (lightweight type 2) with perforations in each layer. Bending properties were evaluated by three-point bend testing. The results showed decreased bending strength (MOR) as well as decreased modulus of elasticity in bending (MOE) with reduction of weight. Bending strength (MOR) was reduced by 33 to 57% and modulus of elasticity (MOE) by 13 to 43% compared to standard (non-lightweight) plywood. Bendability of lightweight plywood expressed by the minimum bending radius (Rmin) and the coefficient of bendability (koh) point to a slight decrease in bendability by 1 to 35% compared to standard (non-lightweight) plywood. The benefit of the proposed plywood lightweight constructions is weight reduction by 16.5 to 24.4%.

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Research on the Bending Properties of the Bamboo-Wood Container Flooring

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.744.366 ◽

2013 ◽

Vol 744 ◽

pp. 366-369

Author(s):

Juan Wei ◽

Dan Zeng ◽

Ming Jie Guan

Keyword(s):

Modulus Of Elasticity ◽

Bending Strength ◽

Accelerated Aging ◽

Modulus Of Rupture ◽

Bending Properties ◽

Before And After ◽

Aging Performance

In this paper, the bending properties of bamboo-wood container flooring and bamboo curtain-OSB container flooring were tested and the six-cycle artificial accelerated aging method of ASTM D1037 was conducted to evaluate the aging performance of two kinds of bamboo-wood container floorings. The modulus of rupture (MOR) and modulus of elasticity (MOE) were tested in the longitudinal and transverse directions before and after aging. The results showed that both the bending strength and MOE decreased after aging. The retention ratios of MOR of the bamboo-wood container flooring and bamboo curtain-OSB container flooring were respectively 43.5%, 72.0%, and the retention ratios of MOE were 54.6%, 76.3%. In general, the effect of aging on the bamboo-wood container flooring was larger than that on the bamboo curtain-OSB container flooring.

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The TUDID Study – Background and Design of a Prospective Cohort

Experimental and Clinical Endocrinology & Diabetes ◽

10.1055/a-1221-9618 ◽

2020 ◽

Author(s):

Benjamin Assad Jaghutriz ◽

Robert Wagner ◽

Stephanie Kullmann ◽

Louise Fritsche ◽

Sabine S. Eckstein ◽

...

Keyword(s):

Diabetes Mellitus ◽

Laboratory Tests ◽

Diabetes Complications ◽

Treatment Options ◽

University Hospital ◽

Tailored Treatment ◽

The Individual

AbstractPrevalence of both type 1 and type 2 diabetes mellitus is growing worldwide and one major cause for morbidity and mortality. However, not every patient develops diabetes-related complications, but causes for the individual susceptibility are still not fully understood. As a platform to address this, we initiated the TUDID (TUebingen DIabetes Database) study, a prospective, monocentric, observational study that includes adults with diabetes mellitus who are treated in the inpatient clinic of a University Hospital in southern Germany. Besides a thorough clinical examination and extensive laboratory tests (with integrated biobanking), major study focuses are the kidneys, the eyes, the vasculature as well as cognition and mood where standardized investigations for early stages for diabetes complications are performed. Analyses of the data generated by this precise characterization of diabetes-related complications will contribute to our understanding of the development and course of such complications, and thus facilitate the implementation of tailored treatment options that can reduce the risk and severity of diabetes-related complications.

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Bending properties of particleboard and MDF layers

Holzforschung ◽

10.1515/hf.2007.116 ◽

2007 ◽

Vol 61 (6) ◽

pp. 717-722 ◽

Cited By ~ 6

Author(s):

Arnold Wilczyński ◽

Marek Kociszewski

Keyword(s):

Modulus Of Elasticity ◽

Bending Strength ◽

Medium Density Fiberboard ◽

Core Layer ◽

Longitudinal Axis ◽

Relative Difference ◽

Layered System ◽

Bending Properties ◽

The Core ◽

The Face

Abstract The modulus of elasticity in bending and the bending strength of the face and core layer of particleboard and medium density fiberboard (MDF) were determined. Three directions of longitudinal axis of test specimens were considered: the direction of the mat forming, the direction perpendicular to it, and the direction perpendicular to the panel plane. The experiments were carried out on specimens that were prepared with strips of layers separated from the panels and glued into laminated assemblies. The bending properties of the core and face layer of the tested panels differed considerably. The core layer properties were on average more than 4 times smaller for particleboard and almost 3 times smaller for MDF. The relative differences between the bending properties were greater than the differences between the densities of the layers. The bending properties of the layers were almost isotropic in the planes of layers and very strongly anisotropic in the planes perpendicular to layers. The modulus of elasticity of the tested panels was calculated for the axis corresponding to the mat forming direction. The calculations were performed on the basis of the moduli of panel layers and based on the layered system theory. The results were compared with the modulus determined directly for entire panels. The relative difference between the compared moduli was found to be very small for both tested panels.

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Effect of structure of laminated wood on bending strength after cyclic loading

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0013.7705 ◽

2019 ◽

Vol 105 ◽

pp. 20-29

Author(s):

JOZEF GÁBORÍK ◽

JOZEF FEKIAČ

Keyword(s):

Cyclic Loading ◽

Flexural Strength ◽

Dynamic Loading ◽

Bending Strength ◽

Flexural Modulus ◽

Bending Properties ◽

Cyclic Bending ◽

Bending Radius ◽

Number Of Cycles ◽

Effect Of Structure

Effect of structure of laminated wood on bending strength after cyclic loading. Laminated wood is particularly suitable for the production of seating and bedding furniture, for its suitable properties. The work is focused on the changes of the bending properties of laminated wood from beech and poplar veneers after its dynamic loading by cyclic bending. As we increase the number of cycles, we notice a decrease in flexural strength, a slight increase in flexural modulus, and a decrease in the number of cycles. Also the increase in the minimum bending radius as well as the flexural coefficient.

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Selected bending properties of mineral-acrylic solid surface material for furniture construction purposes

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0014.3887 ◽

2020 ◽

Vol 110 ◽

pp. 54-60

Author(s):

Anita Wronka ◽

Grzegorz Kowaluk

Keyword(s):

Solid Surface ◽

Modulus Of Elasticity ◽

Elevated Temperatures ◽

Bending Strength ◽

Surface Material ◽

Shape Modification ◽

Bending Properties ◽

Thermal Forming ◽

Thermoplastic Matrix ◽

Trade Names

Selected bending properties of mineral-acrylic solid surface material for furniture construction purposes. The aim of this work was to characterize the bending properties of selected, commercially available panels made with the use of mineral acrylic fillers and thermoplastic matrix (trade names Corian and Staron), with regard to thermal forming. The research showed that when the temperature of the tested materials rises from 20 to 160°C, there is a significant reduction in the value of bending strength (by over 90% for Corian and about 80% for Staron) and the modulus of elasticity (by almost 99% for Corian and by 97% for Staron), which should definitely improve the thermoformability of these materials. Among the two tested materials, Staron is a material that is more susceptible to shape modification at elevated temperatures.

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Diagnosing Diabetes, Diagnosing Colonialism: An Ethnography of the Classification and Counting of a Senegalese Metabolic Disease

Medicine Anthropology Theory | An open-access journal in the anthropology of health illness and medicine ◽

10.17157/mat.8.2.5137 ◽

2021 ◽

Vol 8 (2) ◽

pp. 1-26

Author(s):

Emma N Bunkley

Keyword(s):

Global Health ◽

Public Hospital ◽

Noncommunicable Diseases ◽

Diabetes Diagnosis ◽

Saint Louis ◽

The Public ◽

Production And Consumption ◽

The Individual

This article explores the top-down production of the statistics frequently circulated in global health. These data must first originate in a place like the public hospital in Saint-Louis, Senegal, in doctor’s offices and laboratories and medical archives. At their root, these data are an accumulation of individual bodies, experiences, and intimate diagnostic moments. This aggregation turns the afflicted into categories and statistical regimes that shape a global health understanding of diabetes specifically, and noncommunicable diseases broadly. This article explores the individual diabetes diagnostic moment itself and the politics of the current nosology of Type 1 and Type 2, a seemingly neutral dichotomy that belies colonial relationships between Senegal, slavery, sugar production and consumption, and the effects these relationships have on contemporary conceptions of diabetes diagnosis in Senegal and global health.

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Modeling changes in glucose and glycerol rates of appearance when true basal rates of appearance cannot be readily determined

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00368.2015 ◽

2016 ◽

Vol 310 (5) ◽

pp. E323-E331 ◽

Cited By ~ 8

Author(s):

Laura Pyle ◽

Bryan C. Bergman ◽

Kristen J. Nadeau ◽

Melanie Cree-Green

Keyword(s):

Population Based ◽

Data Set ◽

Glucose Release ◽

Isotope Tracers ◽

Hepatic Glucose ◽

Insulin Dependent ◽

Predicted Values ◽

The Individual

Advancing diabetes care requires accurate physiological assessments. Hyperinsulinemic clamps with stable isotope tracers can simultaneously measure insulin's ability to suppress lipolysis and hepatic glucose release. Traditionally, these methods require an assessment of basal glucose and glycerol rate of appearance (Ra). Basal Ra is challenging to measure in insulin-dependent diabetes, where exogenous insulin required to maintain normoglycemia can raise peripheral insulin concentrations sufficiently to suppress basal Ra. Thus we identified two alternative statistical approaches to describe changes in glucose and glycerol Ra that are less reliant on basal assessments. Sixteen youths (4 type 1 diabetic, 4 type 2 diabetic, 4 lean controls, and 4 obese nondiabetic) underwent a four-phase (“basal” and 10, 16, and 80 mU·m2·min−1) hyperinsulinemic euglycemic clamp with glucose and glycerol tracers. Glucose and glycerol Ra were calculated per phase. A statistical method, the standard two-stage (STS) algorithm, was applied to the individual log insulin vs. Ra curves to calculate a single predicted Ra value. A population-based mixed-effects model (MEM) compared the group average Ra with log insulin curves and described individual deviations from group means and was used to calculate individual predicted Ra. Both models were applied to the participant data, and predicted Ras at the mean insulin concentration per phase (10 for glycerol, 16 for glucose) were calculated, with good agreement between observed and predicted values. In our data set, the MEM was better able to detect group differences. Both STS and MEM can model lipolysis and endogenous glucose release in insulin-dependent states when basal Ra cannot be accurately measured.

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Quality and Bending Properties of Scots Pine (Pinus Sylvestris L.) Sawn Timber

Forests ◽

10.3390/f11111200 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1200

Author(s):

Izabela Burawska-Kupniewska ◽

Sławomir Krzosek ◽

Piotr Mańkowski ◽

Marek Grześkiewicz

Keyword(s):

Mechanical Properties ◽

Scots Pine ◽

Modulus Of Elasticity ◽

Bending Strength ◽

Mechanical Parameters ◽

Bending Properties ◽

Characteristic Values ◽

Sawn Timber ◽

The Moment

The paper presents the partial research results of a mechanical properties study conducted on Scots pine from the Silesian Forestry Area in Poland. The scope of research included the visual strength grading of the timber according to the PN-D-94021:2013 standard, mechanical testing (according to EN 408:2012) and an attempt to assign visuals to the C strength classes. The EN 1912: 2012 standard assigns the visual sorting classes of individual wood species (according to national sorting standards) to the C strength classes introduced by the EN 338: 2018 standard. At the moment, this standard does not assign Polish visual sorting classes (KW, KS, and KG) to C strength classes. The obtained MOE (modulus of elasticity) and MOR (static bending strength) values were corrected according to the EN 384:2018 standard, and their characteristic values were later calculated. On this basis, we proposed a classification of the grading classes determined on the basis of PN-D-94021 into C classes described in EN 338:2018, which is necessary in the process of the transposition of Polish strength grades (KW, KS, KG, and Reject) and the qualification of them in line with EN 1912:2012. The calculated characteristic values of density, MOR and E0 (the modulus of elasticity parallel to the grain) allowed us to assign Polish visual grades KW, KS, and KG to C35, C30, and C20, respectively. The pine timber under research had high physical and mechanical parameters, which translated into high C classes to which the KW, KS, and KG timber categories were assigned.

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The Usefulness of Pine Timber (Pinus sylvestris L.) for the Production of Structural Elements. Part II: Strength Properties of Glued Laminated Timber

Materials ◽

10.3390/ma13184029 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4029

Author(s):

Radosław Mirski ◽

Dorota Dziurka ◽

Monika Chuda-Kowalska ◽

Jakub Kawalerczyk ◽

Marcin Kuliński ◽

...

Keyword(s):

Modulus Of Elasticity ◽

Bending Strength ◽

Strength Properties ◽

Bending Test ◽

Structural Elements ◽

Pine Wood ◽

Glued Laminated Timber ◽

The Individual ◽

Horizontal Arrangement

The paper assessed the feasibility of manufacturing glued structural elements made of pine wood after grading it mechanically in a horizontal arrangement. It was assumed that the pine wood was not free of defects and that the outer lamellas would also be visually inspected. This would result in only rejecting items with large, rotten knots. Beams of the assumed grades GL32c, GL28c and GL24c were made of the examined pine wood. Our study indicated that the expected modulus of elasticity in bending was largely maintained by the designed beam models but that their strength was connected with the quality of the respective lamellas, rather than with their modulus of elasticity. On average, the bending strength of the beams was 44.6 MPa. The cause of their destruction was the individual technical quality of a given item of timber, which was loosely related to its modulus of elasticity, assessed in a bending test. Although the modulus of elasticity of the manufactured beam types differed quite significantly (11.45–14.08 kN/mm2), the bending strength for all types was similar. Significant differences occurred only during a more detailed analysis because lower classes were characterized by a greater variation of the bending strength. In this case, beams with a strength of 24 MPa to 50 MPa appeared.

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Normal and teratological pistillate spikes of Typha angustifolia (Typhaceae): gross aspects of morphology, anatomy, symmetry, and inflorescence dehiscence

Canadian Journal of Botany ◽

10.1139/b91-044 ◽

1991 ◽

Vol 69 (2) ◽

pp. 321-335 ◽

Cited By ~ 4

Author(s):

George J. Wilder

Keyword(s):

Sagittal Plane ◽

Frontal Plane ◽

Mirror Image ◽

Typha Angustifolia ◽

Consistent Manner ◽

Central Stem ◽

Length Width ◽

The Individual

Normal and teratological pistillate spikes of Typha angustifolia were found at the same locality in Ohio, U.S.A., and the individual spikes exhibited radial, dorsiventral, and mirror-image symmetry, as well as polarity. Dorsiventral symmetry provided a frame of reference for comparing normal and teratological individuals. Both kinds of pistillate spikes were interpreted to have dorsal and ventral surfaces, sagittal and frontal planes, right and left sides, length, width, and height. Present in teratological spikes, but absent from normal ones, were either split(s) within the central stem axis or exceptionally long type-1 furrow(s). Split(s) or type-1 furrow(s) divided a teratological spike longitudinally into two to five subunits. Where two subunits were present, division was solely along the sagittal plane, whereas spikes with three to five subunits were divided along the sagittal plane and along, or parallel to, the frontal plane. In the case of teratological spikes with two to four subunits it was possible to number and compare subunits in a consistent manner. On some teratological spikes after splitting, subunits had become bowed, rotated, and curled or folded. Apparently, in teratological spikes, indentations and type-1 and type-2 furrows along the sagittal plane function, collectively, as a line of dehiscence. Key words: Typha, morphology, anatomy, symmetry, inflorescence, dehiscence.

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