Top PDF Effects of water soaking and outdoor exposure on modulus of rupture and internal bond strength of particleboard

Effects of water soaking and outdoor exposure on modulus of rupture and internal bond strength of particleboard

Effects of water soaking and outdoor exposure on modulus of rupture and internal bond strength of particleboard

The swollen thickness causes a reduction of board prop- erties owing to water soaking as discussed above, while it also causes a reduction in properties owing to outdoor exposure. Figure 6a shows the relationships between TC and MOR retention of the PF board exposed outdoors for 1–7 years. The ‘‘Outdoor (North)’’ labels represent Asa- hikawa, Morioka, Noshiro and Tsukuba. The ‘‘Outdoor (South)’’ labels represent Shizuoka, Maniwa, Okayama, and Miyakonojo. This figure also includes the relationships between TC and MOR retention of the PF board soaked in water at various temperatures and times. The MOR reten- tion of both water soaking and outdoor exposure decreased with increasing TC. Moreover, the MOR retention of water soaking was higher than that of outdoor exposure. Figure 6b shows the relationships between TC and IB retention of the PF board. The IB retention also decreased with increasing TC. Although the MOR retention of water soaking was higher than that of outdoor exposure (Fig. 6a), the IB retention of water soaking was almost the same as that of outdoor exposure. The MOR decreases owing to the degradation of face layers [10], while the IB decreases owing to the degradation of the core layer [10, 16]. Water soaking degrades both the face layers and the core layer together, while outdoor exposure degrades the face layers more severely than the core layer as the face layers are directly exposed to sunshine and rain. Thus, the MOR of outdoor exposure decreased more than that of water soaking.
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Predicting internal bond strength of particleboard under outdoor exposure based on climate data: comparison of multiple linear regression and artificial neural network

Predicting internal bond strength of particleboard under outdoor exposure based on climate data: comparison of multiple linear regression and artificial neural network

Outdoor exposure test is one of the standard methods for evaluating the durability of wood-based boards. As a test specimen is exposed in a natural weathering environment for a long-term period, the deterioration of the test speci- men strongly depends on the climate conditions of the exposure locations. Consequently, the results of the out- door exposure tests conducted at specific locations are not generally applicable to locations with different climate conditions. This is a disadvantage of outdoor exposure test. To overcome this problem, Sekino et al. [1] and Kojima et al. [2, 3] extensively collected the outdoor exposure data of commercial wood-based boards exposed at eight repre- sentative locations across Japan, and quantified the dete- rioration of wood-based boards at different locations. The relationships between board deterioration and outdoor exposure conditions were modeled by introducing a com- bination of climate factors, called ‘‘weathering intensity (WI)’’. The best combination of climate factors was determined based on the coefficient of correlation from simple linear regression analysis, and it was found that the WI defined by the logarithm of P ðTemperature PrecipitationÞ was highly correlated to the deterioration of mechanical properties, namely internal bond strength (IB), modulus of rupture, and lateral nail resistance. Although the WI data were well fitted by the regression analysis, it K. Watanabe ( & ) H. Korai
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Effects of water soaking and outdoor exposure on nail joint properties of particleboard

Effects of water soaking and outdoor exposure on nail joint properties of particleboard

Abstract Phenol-formaldehyde resin-bonded particle- board (PF board) and isocyanate resin-bonded particleboard (MDI board) were soaked in water at 40, 70 and 100 °C, and the relationships between soaking conditions and nail joint properties were analyzed. The soaking time to reach the lower limit of nail-head pull-through (NHPT) of the PF board was 2 h at 100 °C, while it took 168 h at 70 °C. The soaking time to reach the lower limit of lateral nail resis- tance (LNR) of the PF board was 24 h at 100 °C, but it did not take 168 h at 70 °C to reach it. The lower limits of NHPT and LNR for the MDI board were higher than those for the PF board. For the PF board, there was a high cor- relation between modulus of rupture, internal bond strength and nail joint properties. Based on the results of water soaking and outdoor exposure, it was shown that thickness change has a significant effect on NHPT and LNR, and that the reduction in NHPT and LNR results from the collapse of bonding points owing to swelling of the board.
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Deterioration of wood-based boards subjected to outdoor exposure in Tsukuba

Deterioration of wood-based boards subjected to outdoor exposure in Tsukuba

Abstract Various types of wood-based boards were ana- lyzed for deterioration after being exposed to an outdoor environment for 5 years in Tsukuba, Japan. In phenol– formaldehyde resin bonded particleboard (PB(PF)) and aspen oriented strand board (OSB(aspen)), longer exposure caused a greater reduction in the modulus of rupture and internal bond strength, an increase in the coefficients of variation, and a decrease in 95 % lower tolerance limit at the 75 % confidence level (95TL). Nail-head pull-through and lateral nail resistance were also reduced by outdoor expo- sure, but their coefficients of variation and 95TL were not significantly affected. In contrast, methylene diphenyl diis- ocyanate bonded medium density fiberboard (MDF(MDI)) only showed a slight deterioration of these properties even after 5-year exposure, and the coefficients of variation and 95TL hardly changed. After 5-year exposure, the retention of shear load in one-plane at relative displacement of 1.0 mm was high in MDF(MDI) and OSB(aspen) at 93.5 and 78.5 %, respectively, but low in PB(PF) at 41.1 %. As with PB(PF), OSB(aspen) also showed a sharp decrease in the modulus of rupture and internal bond strength, but only slightly reduced shear load in one-plane.
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Bending strength and internal bond strength of wood-based boards subjected to various exposure conditions

Bending strength and internal bond strength of wood-based boards subjected to various exposure conditions

Abstract Phenol–formaldehyde resin-bonded particle- board (PF board), methylene diphenyl diisocyanate resin- bonded particleboard (MDI board), aspen oriented strand board (aspen board), Scots pine oriented strand board (pine board), methylene diphenyl diisocyanate resin-bonded medium-density fiberboard (F-MDI board), and melamine– urea–formaldehyde resin-bonded medium-density fiber- board (F-MUF board)—six board types overall—were subjected to high relative humidity (90 %, 20 °C) or cyclic humidity of high/low relative humidity (90/45 %, 20 °C) for 5 years. The PF board and aspen board showed reduction in bending strength [modulus of rupture (MOR)] and internal bond strength (IB); however, the MDI board, pine board, F-MDI board, and F-MUF board showed almost no reduction. Furthermore, the boards were sub- jected to outdoor exposure and Test B (boiling for 2 h) from the Japanese Industrial Standard (JIS); the results showed large reduction in the MOR and IB of the PF board and aspen board. In contrast, outdoor exposure did not greatly reduce the MOR and IB of the F-MUF board and F-MDI board. Although the IB of the F-MUF board reduced after the JIS Test B because of using low-dura- bility resin, the IB retention was as high as 87.8 % for 5-year outdoor exposure.
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Effects of climate change on reduction of internal bond strength of particleboard subjected to various climatic conditions in Japan

Effects of climate change on reduction of internal bond strength of particleboard subjected to various climatic conditions in Japan

CDI increased, and the number of low-temperature areas decreased. The rupture of bonding points caused by out- door exposure led to IB reduction, and biodeterioration accelerated this reduction. In high-temperature areas, par- ticleboard was significantly prone to biodeterioration. The low IB retention areas significantly increased with increas- ing GHG emissions; these areas spread out along the Pacific Ocean side of western Japan and the Sea of Japan in central Japan. Particleboards are difficult to use outdoors because of climate change. Negative IB retention in high- temperature areas is related to the assumption of linearity in multiple regression analysis, which yields a null value. This issue needs to be addressed using an artificial neural network or another method.
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Effects of Continuous and Pulsating Water Jet on CNT/Concrete Composite

Effects of Continuous and Pulsating Water Jet on CNT/Concrete Composite

Erosion effects of PWJ and CWJ on CNT/concrete composite and reference (concrete) samples exposed to their action under various operating parameters were evaluated in terms of material removal rate. Grooves created by the action of the jets were measured using MicroProf FRT optic profilometer. Subsequently, 2D and 3D images of grooves were created and the volume of removed material V was determined using SPIP software. Evaluated length of the groove l was 20 mm, 56 grooves were processed in total. The resistance of the samples to the action of PWJs and CWJs was evaluated in terms of material removal rate ΔV (see in Eq. (1)) which was determined using following formula:
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Effectiveness of principal component analysis for analyzing particleboard subjected to outdoor exposure

Effectiveness of principal component analysis for analyzing particleboard subjected to outdoor exposure

Abstract In order to investigate the strength reduction of particleboards subjected to outdoor exposure at eight sites across Japan, the climate factors, i.e., temperature, sun- shine duration, and precipitation were analyzed using a principal component analysis. The first principal compo- nent (PC1) had an eigenvalue of 2.31 and a proportion of 76.9 %, indicating that the PC1 combines the climate factors into one factor. All of the PC1 eigenvectors dem- onstrated high, positive values for each climate factor, demonstrating that the first principal component score (PC1 score) increases with increasing temperature, sun- shine duration, and precipitation. The PC1 score was introduced as a new index for evaluating strength reduc- tion, as the strength shows a strong correlation with the PC1 score: a higher PC1 score was linked to lower parti- cleboard strength after the outdoor exposure test. The PC1 score can be calculated directly and unambiguously using the climate factors; further, the PC1 score was found to be a more powerful index than each individual climate factors or a combination of them.
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A Study on Effect of Fly Ash and Glass Powder...

A Study on Effect of Fly Ash and Glass Powder...

Concrete production uses large quantities of natural resources as aggregates and contributes to the release of carbon dioxide during the production of cement. One ton of carbon dioxide is released into the atmosphere for the production of one ton of cement, which is approximately 7% of the world's total yearly production of CO2. Concrete is a common construction material in India and its production causes the same environmental concerns as that of regular concrete. Most of developing country facing shortage of post consumers disposal waste site and it’s become very serious problems. In order to address environmental effects associated with cement manufacturing, there is a need to develop alternative binders to make concrete. Consequently extensive research is on going into the use of cement replacements, using many waste materials and industrial by products. Efforts have been made in the concrete industry to use mixture of fly ash and waste glass as partial replacement of coarse or fine aggregates and cement. In this study, finely powdered fly ash and waste glass powder are used as a partial replacement of cement in concrete and compared it with conventional concrete. This work examines the possibility of using mixture of fly ash and waste glass powder as a partial replacement of cement for new concrete. Mixture of fly ash and waste glass powder was partially replaced as 5%, 10%, 15% and 20% and tested for its compressive and permeability strength up to 52 days of age and were compared with those of conventional concrete; from the results obtained, it is found that mixture of fly ash and waste glass powder can be used as cement replacement material up to particle size less than 75µm to prevent alkali silica reaction.
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Physiological and biochemical effects of wate...

Physiological and biochemical effects of wate...

Polyamines (PAs) are little emphatically charged particles [26] that are a piece of the dry season resistance reaction in plants. The PAs in plants incorporate spermine (Spm), spermidine (Spd), and putrescine (Put). Polyamines can communicate with various flagging systems. Furthermore, they direct ionic homeostasis and osmotic potential and balance out layers. The expanded PA substance of plants presented to drought is straightforwardly associated with diminished water misfortune, expanded photosynthetic limit, and improved osmotic detoxification and change. In any case, the full system of activity is ineffectively comprehended. The jobs of PAs include directing quality articulation by means of keeping up particle balance, encouraging the DNA official of interpretation factors, rummaging radicals, settling films, and forestalling senescence by means of the conformational change of DNA and protein phosphorylation [27]. An ongoing report has shown that Oryza sativa can advance PA biosynthesis, particularly the free types of Spm and Spd, and conjugate them into insoluble structures in leaves recently presented to water stress [28,29]. Exogenous PAs can decrease water stress. Their application improves WUE, free proline creation, net photosynthesis, leaf water status, solvent phenolics, and anthocyanins and diminishes oxidative harm to cell films [30,31].
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Effect of Temperature on Fatigue Transition Life and Strength of Aluminum Alloy

Effect of Temperature on Fatigue Transition Life and Strength of Aluminum Alloy

This reduction in fatigue strength may be forming cracks starts to oxidize and the propagation of these cracks become easier [11]. Another reason is the weaking of grain boundaries at high temperatures. As the grain weaken, the transgranular type of cracks changed into intergranular form. Also internal grain cracks and oxidation of fracture surface occur [12].

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The influence of temperature, disinfection and water softening of drinking water on the multiplication of Legionella pneumophila

The influence of temperature, disinfection and water softening of drinking water on the multiplication of Legionella pneumophila

static effect of those temperatures. Bactericidal activity was defined as a 3 log10 decrease in CFU/ml (99.9 % kill-effect). Bacteriostatic activity was defined as <99.9 % kill of bacterial cells after exposure to an anti- microbial [24]. The reproduction of bacteria at 15 °C was minimal, which has also been confirmed by other studies [3, 25]. The number of bacteria incubated at 55 °C after the first 24 h was reduced by more than 6 log in comparison to the culture at 36 °C. After 48 h, their con- centration decreased from 5.7 log CFU mL -1 to 0.1 log CFU mL -1 . After
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Effect of partial replacement of cement by fl...

Effect of partial replacement of cement by fl...

The compressive strength is lower at initial ages due to reduction in the quantity of cement by the replacement with fly ash, resulting in weakening the cohesion of cement paste and adhesion to the aggregates particles. As approximately 75% strength rendering primary mineralogical phases is developed at the ultimate hydration of OPC. The balance Ca(OH)2 whose contribution for strength is insignificant as the fly ash is replaced for cement do not contribute for chemical reaction, because of the fact that sufficient cementitious action of fly ash is not activated at the initial stages and thus the unreactive quantity of fly ash at this stage reflect insignificant effect [11-13].
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Performance Evaluation Of Hybrid Fiber Reinforced Concrete

Performance Evaluation Of Hybrid Fiber Reinforced Concrete

The design of concrete compositions for each mix is given in table 2. The total fiber volume is kept as 0%, 0.5%, 1.0%, 1.5% and 2% of cement weight. For each mix the in the total volume of fiber 60% of it is glass fiber and 40% is polypropylene fiber. The proportion of cement, M sand, coarse aggregate and water cement ratio 0.45 is kept as constant in all mixes. The mix was made with 400 kg/m3 of cement, 576 kg/m3 of M Sand, 516 kg/m3 of 10mm aggregate and 516 kg/m3 of 20mm aggregate. The fiber proportion used in each mix is listed in table 2. Each batch of mix is hand mixed. Initially the cement, M sand and coarse aggregate is thoroughly mixed and then the fiber is added and mixed again ————————————————
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Effect of Drying on Soil Strength and Corn Emergence

Effect of Drying on Soil Strength and Corn Emergence

Additional Index Words: corn emergence, soil strength, modulus of rupture, soil water content, water and soil surface treatments, bare and mulched soil surfaces.. A major factor affecti[r]

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Effects of farmyard manure and nitrogen fertilizers on mobility of phosphorus  and sulphur in wheat and activity of selected hydrolases in soil

Effects of farmyard manure and nitrogen fertilizers on mobility of phosphorus and sulphur in wheat and activity of selected hydrolases in soil

The activity of arylsulphatase in the soil was, on ave- rage, 0.155 mM pNP kg -1 h -1 and depended on the degree of fertilization in the experiment (Table 1). Arylsulphatase activity increased after the long-term application of FYM. In the Haplic Luvisol with the highest FYM rate, the activity of arylsulphatase increased by 8.2%, compared with the control treatments (Table 1). Organic matter affects the level of biomass of microorganisms constituting the main source of soil enzymes (Kotkova et al., 2008). Similarly, the highest rate of the nitrogen fertilizer resulted in the highest activity of arylsulphatase. Current research literature pro- vides various views on the effects of mineral fertilization on the soil enzymatic activity. Piotrowska and Wilczewski (2012) claim that mineral fertilization, especially applied for a long-term period and at high rates, can inhibit enzymatic reactions resulting in inactivation of enzymatic proteins by a high concentration of ions (especially anions) and low soil pH values related to it.
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Effects of water-based exercise on bone health of middle-aged and older adults: a systematic review and meta-analysis

Effects of water-based exercise on bone health of middle-aged and older adults: a systematic review and meta-analysis

Background: Age-related bone loss is a major health concern. Only exercises associated with high-impact and mechanical loading have been linked to a positive effect on bone turnover; however, these types of exercises may not always be appropriate for middle-aged and older adults due to physical decline or chronic disorders such as osteoarthritis. Water-based exercise (WBE) has been shown to affect different components of physical fitness, has lower risks of traumatic fracture, and applies less stress to joints. However, the effects of WBE on bone health are unclear. Objective: This study aimed to explore whether WBE is effective in preventing age-related bone deterioration in middle-aged and older adults.
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Pharmacological and toxicological effects of co-exposure of human gingival fibroblasts to silver nanoparticles and sodium fluoride

Pharmacological and toxicological effects of co-exposure of human gingival fibroblasts to silver nanoparticles and sodium fluoride

Chemical Co, St Louis, MO, USA). After electrophoresis, the gels were washed with 2% Triton X-100 (two times, 20 minutes each), and then incubated in development buffer (50 mmol/L Tris HCl, 200 mmol/L NaCl, 10 mmol/L CaCl 2 , and 1 mmol/L ZnCl 2 , pH = 7.5) at 37 ° C overnight. A condi- tioned medium of HT-1080 human fibrosarcoma cells was used as internal control. After incubation, gels were fixed and stained in 40% methanol, 10% acetic acid, and 0.1% (wt/v) Coomassie Brilliant Blue for 1 hour and then de-stained.

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Influence of Plastic Fines on Compaction and Shear Strength Characteristics of Soil Mixtures

Influence of Plastic Fines on Compaction and Shear Strength Characteristics of Soil Mixtures

 The increase in cohesion of a soil is produced by forces binding the particles together, and is independent of the normal stress. These binding forces are accounted for partly by the, surface tension forces at the air-water interface of the water films surrounding the particles and partly by the intermolecular forces acting between films of water adsorbed on the surfaces of neighbouring particles. Clay thus enables a soil to develop shear strength by virtue of the cohesive forces between the particles.
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Effect of Geotexile and Coir Geocell on CBR Strength of Subgrade Soil

Effect of Geotexile and Coir Geocell on CBR Strength of Subgrade Soil

The scope of present study is limited to, investigation of influence of reinforcement of locally available poor soil as a sustainable subgrade for construction.. The geotextiles and geocell could fulfill the functions as reinforcement material. Therefore in this study we are attempting to improve the strength of locally available weak soil by using geotextiles and geocells and evaluate the influence of geotextiles and geocell on CBR value.

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