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Iis Yuningsih Istie Sekartining Rahayu Dumasari Lumongga 《Wood material science & engineering》2020,15(4):229-236
ABSTRACT The quality of finished wood products depends on the quality of its coating layer. An important indicator for evaluating the quality is Adherence of the paint on the wood surface. The purpose of this research was to analyze the effect of wood surface roughness and the viscosity of acrylic paints (pure acrylic and acrylic copolymer) to the wettability and Adherence for long and short rotation teaks. Wood surface with various degrees of roughness was prepared by sanding with abrasive papers of P120, P240, and P360 grits. Different viscosity of the acrylic paints was prepared composition between paint and water (w/w) of 100:0, 90:10, 80:20, and 70:30. The wettability of the acrylic paints on teak wood surfaces was measured using a sessile drop contact angle method with the S/G model. Adherence of the coating layer was measured using a crosscut test. The results showed that the increase in the roughness (Ra) and the decrease in the viscosity of the paints resulted in the increase in the wettability which leads to better Adherence of acrylic paints on the surface of teak woods. The pure acrylic paint generated better wettability and Adherence compared to the acrylic copolymer. 相似文献
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On-farm trials were conducted to assess the effects of four branch pruning levels on maize grain yield, tree growth and stem
shape. The experimental plots consisted of Gmelina (Gmelina arborea R.Br.) trees planted at 1 × 10 m with maize intercropped in the 10 m-wide alleys between lines of trees. Pruning levels consisted
of retaining a live crown ratio of 60–70% (T
1), 40–50% (T
2); 30–40% (T
3) and of 20–30% (T
4). At the end of the experiment, the total maize grain yield was highest under the high pruning intensity (T
4) (18.06 t ha−1) and lowest under T
1 (14.48 t ha−1). Maize grain yield under the pruning regime T
2 and T
3 were 16.08 and 17.21 t ha−1, respectively. Mean annual increment (MAI) in tree diameter was greater (5.0 cm year−1) under T
1 than those at T
4 (4.1 cm year−1). Pruning regimes T
2 and T
3 resulted in a MAI of 4.7 and 4.5 cm year−1, respectively. Financial analysis showed that maize-tree systems under T
4 were more profitable than under T
1 as long as the reduction of the average dbh at harvest were not greater than 1 cm. Pruning trees intensively also generated
greater returns from labour than moderate pruning, as the greater maize grain yields under T
4 compensated for the cost of pruning and the lower timber yield. In the context of resource-poor farmers, intensive branch
pruning was a practice that prolonged the period of profitable intercropping and was compatible with commercial timber production. 相似文献
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Dorsaf KERFAHI Binu M. TRIPATHI Johan W. Ferry SLIK Rahayu S. SUKRI Salwana JAAFAR Ke DONG Matthew Chidozie OGWU Hyo-Ki KIM Jonathan M. ADAMS 《土壤圈》2019,29(1):12-23
White sand heath forests (WS) or kerangas, an unusual variant of tropical forests in Borneo, characterized by open scrubby vegetation, low productivity, and distinctive plant species composition and soil microbial community, are regarded as a stressful low-pH and/or nutrient environment. We investigated whether the functional soil metagenome also shows a predicted set of indicators of stressful conditions in WS. Based on stress-tolerant strategies exhibited by larger organisms, we hypothesized that genes for stress tolerance, dormancy, sporulation, and nutrient processing are more abundant in the soil microbiota of WS. We also hypothesized that there is less evidence of biotic interaction in white sand soils, with lower connectivity and fewer genes related to organismic interactions. In Brunei, we sampled soils from a WS and a normal primary dipterocarp forest, together with an inland heath, an intermediate forest type. Soil DNA was extracted, and shotgun sequencing was performed using Illumina HiSeq platform, with classification by the Metagenomics Rapid Annotation using Subsystem Technology (MG-RAST). The results, on one hand, supported our hypothesis (on greater abundance of dormancy, virulence, and sporulation-related genes). However, some aspects of our results showed no significant difference (specifically in stress tolerance, antibiotic resistance, viruses, and clustered regularly interspaced short palindrome repeats (CRISPRs)). It appears that in certain respects, the extreme white sand environment produces the predicted strategy of less biotic interaction, but exhibits high soil microbiota connectivity and functional diversity. 相似文献
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James M. Roshetko Subekti Rahayu Wiyono Nugroho H. Prastowo 《Small-Scale Forestry》2008,7(3-4):285-293
Parkia speciosa Hassk. (petai, pete, sator, and stink bean) is a medium to large tree native to Southeast Asia with various medicinal, wood, and shade tree uses. Its seed is an important component of Indonesian, Malaysian, and Thai cuisines. Petai is a common component of smallholder tree gardens throughout Indonesia. Indigenous propagation practices for this species are removal of the seed coat, cutting off ¼ to ½ of the seed, or both, before sowing in prepared beds or containers. These practices are thought by farmers to accelerate seed germination and improve seedling growth. Seed cutting is also practiced to retain part of the seed for household consumption. A research trial was implemented to document the effect of seed shelling and seed cutting on seed germination, seedling growth, and seedling survival. Results indicate that both treatments accelerate—but do not increase—seed germination. Nine days after sowing, the treatments increased germination by 27–32% over the controls; the combination of the treatments increased germination by up to 70%. However, by 35 days all treatments and combinations achieved 100% germination. Seed cutting had a negative effect on seedling diameter and height growth. The combination of no shelling and ½ cutting indicated higher seedling mortality over the study period. The findings support the use of the indigenous seed shelling practice but suggest discontinuation of seed cutting practices. 相似文献
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