Soaking In Cold Water Research Articles

Effect of pre-sowing treatments on seed germination and postgerminative seedling growth of acacia angustissima (mill.)

Seeds of Acacia angustissima were subjected to a control and five pre-sowing (soaking in cold water for 24 hours, soaking in hot water (100° C) for 5 minutes, immersion in 60 % H2SO4 for 30 seconds, immersion in 60 % H2SO4 for 5 minutes, and immersion in 60 % H2SO4 for 15 minutes) treatments. The number of seeds that sprouted was recorded daily for calculation of germination indices. When there had been no further germination in any of the treatments for four weeks, the height, number of leaves, number of leaflets, and root length of seedlings were determined. One-way analysis of variance was used to test the effects of the pre-sowing treatments on seed germination and seedling growth. Final Germination Percentage, Germination Rate Index, and Seedling Vigour Index were significantly higher in the warm water than other five treatments which displayed similar responses of the traits. Similar, the warm water pre-treatment resulted in the longest seedlings, when shoot height and / or root length was considered. There was no significant effect of treatment on Mean Germination Time, number of leaves, and number of leaflets. The findings suggest that hot water pre-sowing treatment is the most suitable for seed germination and initial seedling height attainment of Acacia angustissima.

Effect of pre-sowing treatments on seed germination and postgerminative seedling growth of acacia angustissima (mill.)

Seeds of Acacia angustissima were subjected to a control and five pre-sowing (soaking in cold water for 24 hours, soaking in hot water (100° C) for 5 minutes, immersion in 60 % H2SO4 for 30 seconds, immersion in 60 % H2SO4 for 5 minutes, and immersion in 60 % H2SO4 for 15 minutes) treatments. The number of seeds that sprouted was recorded daily for calculation of germination indices. When there had been no further germination in any of the treatments for four weeks, the height, number of leaves, number of leaflets, and root length of seedlings were determined. One-way analysis of variance was used to test the effects of the pre-sowing treatments on seed germination and seedling growth. Final Germination Percentage, Germination Rate Index, and Seedling Vigour Index were significantly higher in the warm water than other five treatments which displayed similar responses of the traits. Similar, the warm water pre-treatment resulted in the longest seedlings, when shoot height and / or root length was considered. There was no significant effect of treatment on Mean Germination Time, number of leaves, and number of leaflets. The findings suggest that hot water pre-sowing treatment is the most suitable for seed germination and initial seedling height attainment of Acacia angustissima.

Preparation and characterization of polymeric cellulose wood adhesive with excellent bonding properties and water resistance

Developing the most abundant cellulose resources in nature as wood adhesives is a challenging but significant work. In this study, an oxidized cellulose-hexamethylene diamine-urea (OCHU) resin adhesive, of high bonding performance, and excellent water resistance has been prepared. The cellulose was firstly enzymatically hydrolyzed to increase its solubility and expose more hydroxyl groups, then oxidized by sodium periodate (NaIO4) to generate a biological compound being rich of aldehyde groups. The OCHU adhesive was prepared by crosslinking oxidized cellulose (OC) with a synthetic reactive polyurea (HU) polymer, which was formed through the deamidation reaction between hexamethylenediamine (H) and urea (U). This adhesive exhibited a 24 h cold water soaking strength of 1.61 MPa, 3 h hot water (63 °C) strength of 1.05 MPa and a dry strength of 1.71 MPa. Compared to oxidized cellulose-hexamethylenediamine (OCH) adhesive, a significant increase of 60 % in this adhesive's wet strength. The Schiff base and addition reactions in the preparation were confirmed by XPS, solid-state NMR, and FTIR. This cellulose-based wood adhesive has great market competitiveness for mass production and application in the plywood industry, due to its excellent bonding properties.

Seed priming by cold scarification and Moringa-based bio-stimulant on the germination of Artemisia afra

Artemisia afra is a frequently utilized medicinal plant in diverse cultural traditions for the management of various health conditions. Despite its natural habitat, limited efforts have been dedicated to its systematic cultivation, resulting in a paucity of documented information concerning its seed biology and germination characteristics. This study aimed to determine the effect of different temperatures, scarification, light conditions and priming with biostimulant on the seed germination of Artemisia afra. The seeds were exposed to different scarification methods including rubbing (sandpaper), hot and cold-water soaking, acid (H2SO4) and fermentation (EM) and compared with untreated seeds (control). Photoperiods included constant light, alternating light (16/8 hours) and continuous darkness at 15 °C, 25 °C and 35 °C. Results revealed that 25 °C temperature significantly improved germination while no germination was obtained at 15°C and 35°C. Hot and cold-water scarification resulted in improved germination. There was no germination observed for fermented seeds in all the experiments. In photoperiod, the highest germination percentage of 70 % was observed under alternating light. Using Moringa based biostimulant under alternating light conditions at 25 °C resulted in improved MGT. The information generated from this study will contribute to bridging the scientific gap by generating information on optimum requirements for propagating A. afra through seeds.

Functional Properties of Tannia Corms (Xanthosoma sagittifolium (L.) Schott) Flour As Affected By Cooking, Soaking, and Peeling Processes

The study aimed to characterize the functional properties of tannia (Xanthosoma sagittifolium (L.) Schott) flour to realize the crop’s immense potential as an alternative ingredient. Experiments were conducted using a 23 factorial design with cooking, soaking, and peeling as the independent variables. The predicted best treatment was subjected to proximate analysis. Results revealed that tannia flour had high water absorption capacity (71.6-75.9%), oil absorption capacity (52.3-58.3%), foaming stability (94.0-97.0%), and swelling power (53.1-75.0%). The flour obtained had a low gelling point (46.7°C-58.7°C), boiling point (52.0-64.0°C), and least gelation concentration (4-5.33%). Further, peeling significantly affected the water absorption capacity, foaming capacity and stability, and swelling power of tannia flour, while cooking and soaking significantly affected tannia flour’s foaming capacity and gelling point. The interaction of factors (peeling, cooking, and soaking) was also found to significantly affect the functional properties of tannia flour, except for the least gelation concentration. The predicted best treatment was the combination of steaming, cold water soaking, and peeled tannia (Treatment 7), which contains lower moisture (4.31%), ash (0.52%), crude protein (4.41%), crude fat (1.01%), but higher contents of carbohydrates (89.74%), and crude fiber (10.5%.). Overall, tannia flour has good functional properties with the best treatment containing comparable amounts of nutrients with wheat flour except for ash, crude protein, and crude fat. This provides an advantage in enhancing its applicability in various food products and in the production of energy and fiber-rich food products.

Germination responses with different treatments, seed vigour and seedling growth of Pterolobium stellatum (Forssk.) provenances stored from 19 to 30 years

Knowledge of the genetic variability of different species for conservation purposes and quality seedling production after longer storage time is important. The aim of the research paper was to examine the effect of longer seed storage periods (19–30 year) on seed viability, seed vigour and initial growth of seedlings from five provenances of Pterolobium stellatum (Forssk). Seeds collected from Dabena, Gambo, Agaro, Bishofitu, and Merti localities and stored for 19, 19, 21, 25, and 30 years, respectively used for the study. Different seed dormancy-breaking treatments such as; soaking in cold water for 48 h (CW-48); soaking in hot water for 10 min (HW-10); 20 min (HW-20) and mechanical scarification; i.e., nicking (NK) used for the germination of the seeds. A randomized complete block design was used for the experiment and the study undertaken in a greenhouse. For each treatment, four replications and for each replication, 50 seeds were used. One-way analysis of variance was used for germination index, early seedling growth and seed vigour index data. The results showed that for all the provenance seeds stored for different periods, NK treatment resulted relatively in a higher mean germination percentage and germination indices as compared to the other pre-treatments. The seed vigour index result showed significant differences among the different provenances (P < 0.001). Similarly, there were significant differences among the early growth of seedlings germinated from different provenance seeds (P < 0.001). The seeds collected from Merti provenance and stored for 30 years and Dabena provenance, stored for 19 years, have relatively resulted in higher mean germination index, seed vigour and seedling growth relative to the other studied provenance seeds. We observed that provenance had a more significant influence on germination, seed vigour and seedling growth than the seed storage period for the P. stellatum. Finally it is recommended that despite there is inter population variation, the seeds of P. stellatum can be stored for a longer time and application of nicking as a dormancy breaking treatment could enhance seed germination of the species.

Enhancing Germination of Seeds of a Multipurpose Tree Species Combretum molle

Combretum molle R. Br. ex G. Don (Combretaceae) is a highly valued indigenous multipurpose tree species that has gained considerable attention in recent times due to its importance as a medicinal plant as well as an alternative species for wood and charcoal production. However, we lack adequate information on simple and appropriate methods that could be used to break its distinct seed dormancy to support domestication of wild populations apparently undergoing over exploitation and the negative impacts of deforestation. Eight pre-treatment methods involving complete removal of wing, complete removal of mesocarp, overnight soaking in cold water (24 °C) and partial removal of wing by scorching with fire, and their combinations were tested against the seed dormancy. Of all, the complete removal of mesocarp and overnight soaking in cold water followed with additional soaking in cold water for 24 h took the shortest imbibition (2 days) and germination (7 days) periods, highest germination value (76) and germination energy (80%). Similarly, the same treatment scored significantly (P &lt; 0.05) higher cumulative germination of 72%. To obtain best germination traits, C. molle seeds should be pre-treated by removing the mesocarp and overnight soaking in cold water followed with additional soaking in cold water for 24 h, before sowing. These results have wide implications including supporting domestication and forest landscapes restoration in Tanzania.&#x0D; Keywords: Domestication; Restoration; Indigenous species; Dormancy; Lesser known species&#x0D;

Seed Morphometry and Different Pre-sowing Treatments on Seed Germination of Spondias pinnata Linn. under Nursery Condition

The present investigation was carried out during 2018–19 to evaluate the variation in seed dimension and most promising seed pre-treatments for accelerating germination of Spondias pinnata Linn. The various pre-sowing treatments were the Control (no treatment); soaking in cold water for 24 hours; soaking in cold water for 48 h; soaking in cold water for 72 h; soaking in 100 ppm thiourea for 24 h; soaking in 200 ppm thiourea for 24 h; soaking in 400 ppm thiourea for 24 h; soaking in 800ppm thiourea for 24 h; soaking in 1000 ppm thiourea for 24 h; soaking in 100 ppm KNO3 for 12 h; soaking in 200 ppm KNO3 for 12 h; soaking in 400 ppm KNO3 for 12 h; soaking in 800 ppm KNO3 for 12 h and soaking in 1000 ppm KNO3 for 12 h. The experiment was laid out in randomised block design with 13 pre-sowing treatments and the control with three replications of 100 seeds. The highest (54.33%) germination percentage was observed from cold-water for 48 hrs followed by thiourea 1000 ppm for 24 hrs (50.00%) and potassium nitrate 200 ppm for 12 hrs (48.67%). Parameters like germination value, mean germination time, root length, shoot length and seedling vigour index were significantly different among all the pre-treatments.

Effect of Chicken Thigh Soaking Time at Temperature 5-10°C on Total Microbes and pH

The study aims to examine the effect of immersion time of chicken thighs at cold temperatures of 5-10°C on total microbes and pH, reviewing the time of soaking chicken thighs at cold temperatures of 5-10°C with the best level. The research material used is 20 pieces of broiler chicken thighs, water, ice cubes, PCA media, aquadest, alcohol 70%, buffer solution, NaCl 0.85%. Experimental research method using Complete RandomIzed Design (RAL) with 4 treatments and 5 repeats. The treatment given is R1 chicken thighs with cold water soaking 0 minutes (momentary), R2 is chicken thighs with cold water soaking for 15 minutes, R3 is chicken thighs with cold water soaking for 30 minutes, and R4 is chicken thighs with cold water soaking for 45 minutes. The results of the study of total microbes obtained average R1 of 6,20 x 107 cfu/g, R2 of 5,13 x 106 cfu/g, R3 of 3,60 x 106 cfu/g and R4 of 1,14 x 106 cfu/g and the pH research result obtained R1 average of 5,86; R2 was 6,16 ; R3 was 6,56 and R4 was 5,95. The results showed that the length of immersion of chicken thighs in cold water 5-10°C had a very real effect (P&lt;0,01) on total microbes and had an unreal effect (P&gt;0,05) on pH.The conclusion, soaking chicken thighs at cold temperatures of 5-10°C can decrease the number of microbes and the pH value remains. The length of soaking of chicken thighs at cold temperatures of 5-10°C is best 40 minutes.

Understanding the PLA–Wood Adhesion Interface for the Development of PLA-Bonded Softwood Laminates

With polylactic acid (PLA) usage projected to increase in wood-based composite materials, a study comparing composite processing parameters with resulting PLA−wood adhesion and panel performance is warranted. In this study, PLA-softwood veneer laminates have been prepared and spatial chemical imaging via FTIR analysis was applied to identify PLA bondlines characterizing bondline thickness and the extent of PLA migration into the wood matrix. These PLA–wood adhesion interface characteristics have been compared with the performance of panels varying in pressing temperature, pressing time and PLA grades. For amorphous PLA, bondline thicknesses (60–120 μm) were similar, pressing at 140 °C or 160 °C, whereas with semi-crystalline PLA, the bondline thickness (340 μm) significantly reduced (155–240 μm) only when internal panel temperatures exceeded 140 °C during pressing. Internal temperatures also impacted PLA penetration, with greater PLA migration from bondlines evident with higher pressing temperatures and times with distinctions between PLA grades and bondline position. Performance testing revealed thinner PLA bondlines were associated with greater dry strength for both PLA grades. Cold-water soaking revealed laminated panels exhibit a range of wet-strength performance related to panel-pressing regimes with the semi-crystalline PLA pressed at 180 °C having similar tensile strength in dry and wet states. Moreover, an excellent correlation between wet-strength performance and bondline thickness and penetration values was evident for this PLA grade. Overall, study findings demonstrate PLA wood composite performance can be tuned through a combination of the PLA grade and the pressing regime employed.

Thermosetting environment‐friendly polyamide adhesives prepared with citric acid and hexanediamine

AbstractThermosetting polyamide resins prepared by reacting citric acid with hexanediamine (CH) were synthesized and used for plywood bonding in this work, and the effects of reaction time, molar ratio of citric acid, and hexanediamine on the bonding performance have been studied. Fourier transform‐infrared (FT‐IR) and liquid chromatography‐mass spectrometry (LC–MS) were used to determine the structures of the resins. Differential scanning calorimeter (DSC), dynamic mechanical properties (DMA), and thermogravimetric analysis (TG) were used to analyze its thermal properties. The results show that amide bonds can be formed by the reaction of carboxyl and amino groups, which acted as reaction raw materials that can undergo further polycondensation to render possible the formation of a cured cross‐linked network, thus to ensure the bonding performance of the adhesives. Meanwhile, CH adhesives presented excellent bonding strength and water resistance above the standard requirements (≥0.7 MPa). In particular, the plywood prepared by CH resin with molar ratio of citric acid to hexanediamine of 1:1.5 and reaction time of 3 h exhibited the best performance, the dry shear strength being as high as 1.96 MPa, 24 h cold water soaking strength of 0.87 MPa, and 3 h hot water (63°C) soaking wet strength attaining 1.24 MPa.

Preparation and analysis of Jatropha curcas seed flour‐based plywood bonding adhesives by oxidation methods

AbstractJatropha seeds flour is by‐product from the production of biomass diesel, which mainly composed of proteins and oligomeric carbohydrates. To create an environmentally friendly, low‐cost, and well performance adhesive for plywood bonding, the Jatropha seeds flour was used to prepare a protein‐based adhesives by oxidized with sodium periodate (NaIO4) and potassium permanganate (KMnO4) at room temperature in this present work. The effect of two oxidizing agents on the bonding strength and water resistance were investigated. Differential scanning calorimetry, and dynamic thermomechanical analysis were combined to study the thermal performance of this bio‐based adhesives, and Fourier transform infrared spectroscopy was to characterize structural changes in the reaction process. The results show that the Jatropha protein adhesives oxidized by NaIO4 exhibited a good dry strength, but not on the 24 h cold water soaking wet strength and 3 h hot water (63°C) soaking wet strength. While the performance of the adhesive with KMnO4 oxidation treatment has significantly improved, especially the wet strength of 24 h cold water soaking and 3 h hot water (63°C) soaking as high as 0.84 MPa, 0.77 MPa respectively, which conformed to the standard requirement of GB/T9846‐2015 (≥0.7 MPa). Thus, the Potassium permanganate (KMnO4) oxidant was favored for Jatropha protein oxidation to prepare a protein adhesives, and its preparation process has been studied also in this work, meanwhile, the optimal oxidant addition ratio was confirmed as 12% based on the protein flour.

A Study of Concept to Prepare Totally Biosourced Wood Adhesives from Only Soy Protein and Tannin.

This is a study of concept on the initial application for wood adhesives totally biosourced from the covalent reaction between soy protein isolate (SPI) and a commercial flavonoid tannin, namely quebracho tannin. The adhesive is composed exclusively of the two vegetable biomaterials mentioned and thus is totally biosourced and non-toxic, as tannin has been classified as being not at all toxic by the European Commission REACH program. The pre-reaction between the two yielded the best plywood bonding results when limited to a temperature of 40 °C, final cross-linking being achieved during the plywood higher temperature hot pressing procedure, as for any other thermosetting adhesive. Pre-reaction at higher temperatures, namely 60 °C and 80 °C, achieved extensive premature cross-linking that lost any activity to cross-link further when hot pressed for preparing plywood. The reaction was followed by thermomechanical analysis, by matrix assisted laser desorption ionization time of flight (MALDI ToF) mass spectrometry, and by plywood shear strength tested dry, after a 24 h cold water soak and 1 h in boiling water. The adhesive of this approach lends itself to be further reinforced by the multitude of approaches on soy resins already developed by several other research groups.

Effect of Seed Size and Different Pretreatment Methods on Germination of Albizia zygia (DC.) J. F. Macbr

Albizia zygia produces valuable timber which has received some level of prominence in the international market. However, the seeds are dormant, and the tree species remain undomesticated. This study was conducted to evaluate the effect of seed size and presowing on the germination of Albizia zygia in a nursery. Seeds were grouped into four categories in regard to their length, small (≤0.5 cm), medium (&gt; 0.5 &lt; 0.8 cm), large (≥0.8 cm), and mixture of small, medium, and large seeds. The seeds were subjected to five main seed pretreatment methods, namely, soaking in sulphuric acid (H2SO4) for 2 minutes, mechanical scarification, soaking in hot water for 5 minutes, soaking in cold water for 24 hours, and control where seeds were sown without any treatment. The results indicate that combination of mechanical scarification and large seeds produced the highest (100%) germination. Hot water treatment was effective in large seeds producing 69.0% germination. The increased germination for mechanically scarified seeds suggests that seed dormancy in Albizia zygia is mainly due to its hard seed coat. Therefore, it is recommended to farmers to adopt use of mechanical scarification and large seeds, since it is safe and effective.

Development of a decorticator for Buchanania lanzan nuts and its process optimization

AbstractThe study was aimed to develop a decorticator and to standardize the process for separation kernels from nuts. The developed machine was optimized using independent parameters, that is, cold water soaking, steaming, and sand roasting, different moisture levels (7 and 9%), cylinder speed (150 and 300 rpm), and concave clearances (7.5 and 8 mm). The optimum performance of a developed decorticator was obtained when sand roasted nuts (7% moisture content) fed at a cylinder speed of 300 rpm and a concave clearance of 8 mm. At this condition, decortication efficiency, capacity, and whole kernel recovery were 96.10, 64.15, and 12.60%, respectively. The decorticator produced 126 g whole kernels (56.71%) from 1 kg of nuts. The independent process parameters have significant effect on response variables. The machine had low labor requirement, high efficiency, and ease to operate; thus, the results will be useful for processing of nuts and in other studies.Practical applicationsThe chironji nut decorticator has application to decorticate nuts to produce kernel at manufacturing site of food, flavor, cosmetic, and pharmaceutical industries. The kernels have very short shelf‐life because they are very soft and susceptible to mechanical damage and spoilage. The available decorticators have very limited efficiency and more breakage thus the results can be utilized to fill existing gap to obtain increased efficiency and less damage. The results of different treatments to nuts will assist future studies as well.

Bonding Wood Veneer with Biobased Poly(Lactic Acid) Thermoplastic Polyesters: Potential Applications for Consolidated Wood Veneer and Overlay Products

This study reports on the use of poly(lactic acid) (PLA) as a renewable thermoplastic adhesive for laminated panels using birch, spruce, and pine veneers. Consolidated panels were prepared from veneer and PLA foils by hot-pressing from 140 to 180 °C to achieve minimum bondline temperatures. Evaluation of panel properties revealed that the PLA-bonded panels met minimum tensile strength and internal bond strength performance criteria. However, the adhesion interface which developed within individual bondlines varied with distinctions between hardwood and softwood species and PLA grades. Birch samples developed greater bondline strength with a higher pressing temperature using semi-crystalline PLA, whereas higher temperatures produced a poorer performance with the use of amorphous PLA. Panels formed with spruce or pine veneers had lower bondline performance and were also similarly distinguished by their pressing temperature and PLA grade. Furthermore, the potential for PLA-bonded laminated panels was demonstrated by cold water soak testing. Samples exhibiting relatively greater bondline adhesion had wet tensile strength values comparable to those tested in dry state. Our study outcomes suggest the potential for PLA bonding of veneers and panel overlays with the added benefits of being renewable and a no added formaldehyde system.

STUDY OF QUALITY OF SNACK GHERKIN TINNED FOOD

This work considers a problem of raising a marinade quality for producing snack gherkin tinned food. There is offered a new way for raising a marinade food value. The aim of the work is to raise a tinned food quality at the expanse of recipe peculiarities of ingredients. There is offered to produce snack tinned food with adding mustard. The tinned food contains gherkin, sugar refined sunflower oil, kitchen vinegar 9 %, salt, dry mustard, grinded red pepper and chopped garlic. An optimal recipe for diminishing mass consumption of the raw materials is developed in the study. The tinned food recipe was modeled by the simplex method that allowed to get an optimal variant with a maximal complex quality parameter. According to the recipe, a bank of І-82-500 needs: gherkin – 375 g, sugar – 37.5 g, refined sunflower oil – 37.5 g., kitchen vinegar 9 % – 37.75 g, salt – 3.75 g, garlic – 3.75 g, mustard (powder) – 3.75 g, grinded red pepper – 1 g. It is established, that the new snack tinned food is characterized by high organoleptic properties. The technological scheme at producing the snack tinned food “Pickled gherkins with mustard” includes the following processes: preparation of the raw materials (cleaning, sorting), soaking in cold water for 5–8 hours; inspection; pouring with marinade; mixing and infusion; packing; closing; sterilization, formation of ready products. Gherkins are processed by the standard technology for pickled vegetables. Physical-chemical parameters in the raw materials and ready products were studied during the work: the content of soluble dry substances – by the refractometric method; the total content of organic acids – by titration; рН-medium – by the potentiometric method; the content of nitrates – by the ionometric method. Mustard was added for raising a food value and quality of the snack tinned food. It is healthy, because it improves the appetite, disintegrates fats and facilitates digestion of protein meals, at that activating metabolism. Main healthy properties of mustard are antimicrobial, antifungal, antioxidant and anti-inflammatory effects. Added spices and garlic give a pleasant taste and add the composition of mineral substances. The developed recipe is designed for production technological lines and recommended for implementation at processing enterprises. The conducted work testifies to the expedience of producing new types of snack tinned food, which food value is increased and organoleptic parameters are improved at the expanse of ingredients.

Tannin plywood bioadhesives with non-volatile aldehydes generation by specific oxidation of mono- and disaccharides

Sodium periodate has been shown to cleave glucose by specific oxidation to yield a number of non-volatile aldehydes which can react with the phenolic compounds in tannin extract and lead to tannin cross-linking and hardening. This approach to prepare a tannin resin useable for wood adhesives can be used by either treating with periodate a mixture of tannin and glucose, or to treat glucose beforehand with periodate to cleave it and generate the aldehydes, and only afterwards to mix it with the tannin. The results obtained with these two methods are identical, but the latter method avoids oxidation of tannin. The aldehydes were generated either by direct cleavage of glucose C–C bonds carrying vicinal oriented hydroxyls, or by recombination of the aldehydes so formed by aldol condensation or by water elimination between two aldehyde groups. MALDI ToF analysis indicated that all the three types of aldehydes appeared to react with the polyphenols in the tannin. Thermomechanical analysis (TMA) and plywood bonded with the tannin + glucose + periodate mixes gave good bonding results, with dry, 24 h cold water soaking and 3 h at 63 °C shear strength values improving concomitantly to the proportion of periodate used for the oxidation step.

Particleboard Manufactured from Rubberwood RRIM 2002 Clone Planted with Different Fertilizer Treatment

This work focus on the effects of SRF (Slow Release Fertilizer) + NPK fertilizer rates on the properties of rubberwood particleboards produced. The particleboards were fabricated using rubber tree trial clone RRIM 2002. RRIM 2002 clone still in trial plot with age of 4-year old and classified as Latex Timber Clone which estimated to produce large wood volume and also better latex yield. The properties of particleboard were categorized and evaluated based on fertilizer treatment applied on RRIM 2002 clone tree: T1 (SRF + NPK at normal rate), T2 (SRF + 1.5 x NPK at normal rate), T3 (SRF + 2.0 x NPK at normal rate) and T4 (SRF + 2.5 x NPK at normal rate, control (NPK at normal rate). The resin used for particleboard fabrication was urea formaldehyde (UF) (63.9% solid) type E1. The resin content is 10%. The thickness of board is 10 mm with density 700 kgm-3 . The particleboards were fabricated and assessed in accordance to Japanese Industrial Standard for Particleboard (JIS A 5908-2003). The properties that been assessed were on modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding (IB), thickness swelling (TS) and water absorption (WA). From this study, it is found that fertilizer treatment influences the particle recovery and performance of particleboard especially on dimensional stability and internal bonding properties which significantly affected. The MOR and MOE of particleboard made from rubber trees that treated with SRF-NPK fertilizer showed better performance compared to that of with NPK fertilizer alone (control), however, the differences were not significant. In term of IB, no specific trend was observed. Lastly, for dimensional stability (TS and WA), particleboard produced from SRF-NPK fertilizer reduced the board stability when subjected to cold water soak.

Study on the mechanical properties of nanoclay-epoxy composites under different hygrothermal aging conditions

The current study objectives to prepare and characterize nanoclay-epoxy composites (NECs) with a varying weight percentage of nanoclay. The NECs are prepared by mixing nanoclay and epoxy resin using a sonicator. The mixture is mold formed using direct casting technique, to make specimens as per ASTM standards. The specimens are treated with three hygrothermal aging conditions viz., cold water soaking, boiling water soaking and thermal shock. The properties of the specimens are characterized based on tensile and flexural tests as per ASTM standards. The results revealed that hygrothermal aging conditions have an adverse effect on the properties of neat epoxy. Addition of nanoclay increased the mechanical properties and decreased the effect of water soaking conditions. SEM images disclosed the reasons for the failure of the specimens. Conclusions are drawn based on comparison done in obtained results of dry specimens, and the specimens that underwent hygrothermal aging conditions.