Hard Wood Research Articles

Vegetative Propagation of Eureka Seedless Lemon (Citrus limon L.Cv Eureka seedless) using Different Types of Stem Cutting and Concentrations of Indole-3-Butyric Acid in Winter

Citrus can be propagated successfully through stem cutting. However, success of the propagation is depends on various internal as well as external factors. The 2*7 factorial Randomized Complete Block Design (RCBD) experiment was conducted at the Institute of Agriculture and Animal Sciences, Paklihawa Campus, Rupandehi, Nepal from 22 November 2019 to 5 March 2020 to assess the interaction effect of types of stem cuttings and indole 3 butyric acid (IBA) concentrations on the vegetative propagation of Eureka seedless lemon in winter. Stem cutting types had two levels: hardwood and semi-hardwood cutting and IBA concentrations had seven different level i.e control, 500 ppm, 1000 ppm, 2000 ppm, 3000 ppm, 4000 ppm, and 5000 ppm respectively forming overall 14 treatments and three replications. Statistically, significant interaction effects were seen in root parameters. The highest total number of the root(18.00) were found in hardwood cuttings treated with 4000 ppm and lowest total number of roots(1.66) was found in semi-hardwood cuttings treated with 0 ppm of IBA. A statistically significant interaction effect was not found in most of the shoot parameters. However, maximum sprouting (93.33%), the average number of shoots (4.67), average length of the shoot (7.86), and minimum days for first sprouting (30.67 days) were found in hard wood cuttings treated with 4000 ppm IBA. Considering different root and shoot parameters, hardwood cuttings treated with 4000 ppm performed best for root and shoot development. Thus, hardwood cuttings treated with 4000 ppm IBA can be appropriate method for easy and early propagation of eureka seedless lemon.

Interacting effects of botanicals, biocontrol agents, and potting media on Rhizoctonia solani led damping-off of okra seedlings

The interacting effects of botanicals, biocontrol agents, and potting media against the Rhizoctonia solani led damping-off in okra ( Abelmoschus esculentus L.) were investigated. The treatments comprised of different combinations of extracts of five botanicals:wood apple/Indian bael – Aegle marmelos L., Neem – Azadirachta indica A. Juss, Turmeric – Curcuma longa L., Ginger – Zingiber officinale Roscoe, and Onion – Allium cepa L.,and two biocontrol agents, Pseudomonas fluorescens and Trichoderma viride as first factors and two potting media; vermicompost with soil and farm yard manure with soil as the second factor in a completely randomized design with 42 treatments and 4 replications. The seeds were sown after pathogen inoculation. Okra seedling health was recorded daily for the first 16 days after sowing. Pseudomonas soil treatment and Pseudomonas+onion seed treatment showed the least pre-emergence damping off (35%). Almost all the combinations of wood apple extracts showed inhibitory effects on seed germination and growth of seedlings. The greatest number of days for the onset of post-emergence damping-off was recorded with Pseudomonas + Onion seed treatment (14.88 days) followed by Pseudomonas seed treatment (14.13 days). Germination Index (GI) was better for farm yard manure(0.32) than Vermicompost substrates (0.23). The GI was greatest in Pseudomonas soil treatment (0.53) followed by Pseudomonas + Onion seed treatment (0.51). Similarly, Dickson Quality Index (DQI) was greatest for Pseudomonas + Neem seed treatment (0.0015), with a greater value of DQI indicating better seedling quality. No significant interaction was observed between the substrates and biocontrol agents for any studied parameters. Pseudomonas + Onion seed treatment and Pseudomonas soil treatment were most effective for controlling R. solani -led damping-off in okra. • We studied the control of damping-off disease in okra seedlings. • Seed treatment with Pseudomonas fluorescens and onion blub extract were effective. • Trichoderma treatment in combination with other botanicals decreased the efficacy. • Hard wood apple extract had inhibitory effects on the germination of okra.

Impact of Circular Saw Blade Design on Forces During Cross-Cutting of Wood

This paper evaluates the impact of the number of saw blade teeth on kinematic and dynamic parameters during cross-cutting of soft and hard woods with mitre saw BOSCH GCM 12 GLD Professional. The forces measured using a three-dimensional XYZ dynamometer Kistler 9257B and subsequent calculation based on a mathematical model were applied in the Ernst-Merchant diagram and the forces acting in the cutting of spruce and oak planks were analysed and compared. The wood cutting was performed by four geometrically and structurally similar blades with a 300 mm diameter and with different count of WZ-shaped teeth (z = 26, 36, 48, 60). The optimum saw blade for the given cutting conditions was subsequently assessed by statistical analysis. Unlike many studies researching the cutting resistances in transversal and longitudinal wood cutting, this experiment and force analysis was performed in dependence on the constant feed force.

The Impact of Fibre Oxidation on the Preparation of Cellulose Nanocrystals (CNC)

This study aimed to evaluate the effect of fibre oxidation on the extent of substituted sulfate on cellulose nanocrystals (CNC). In this investigation, fully bleached softwood (SW) and hardwood (HW) pulps from an Alberta pulp mill were oxidized under low (4%), medium (10%), and the higher-end of medium (14%) oxygen consistencies. The oxidized pulp samples were hydrolyzed with concentrated sulfuric acid under conventional procedures to produce CNC. The CNC materials were then characterized by different qualitative and quantitative techniques to evaluate the effect of oxidations on the number of substituted sulfates and the overall sulfate charge of isolated CNC to develop novel high-value applications. The experimental data show that fibre oxidation helped improve the overall CNC yield, with lower half-ester sulfate contents compared to the controls. The half-ester sulfate contents and the viscosity for SW CNC were found to be higher than their HW CNC counterparts. However, the thermal stability of CNC was found to be better for HW than SW pulps. The emerging data help to prepare and engineer CNC tailored to specific applications.

Investigation of some technological properties of Anatolian boxwood (Buxus sempervirens L.) stem wood

şimşiri (B. sempervirens L.) gövde odununun anatomik özellikleri, rutubet miktarı, yoğunluk değerleri, liflere paralel basınç direnci, renk parametreleri ve yüzey pürüzlülük değerleri belirlenmiştir. Araştırma materyali Trabzon’un Çaykara ilçesinden alınmıştır. Gövde odunu, gerçekleştirilecek testler için kesilerek deney örnekleri elde edilmiş ve deney örnekleri hava kurusu hale gelinceye kadar iklimlendirme odasında bekletilmiştir. Testler, ilgili standartlara göre gerçekleştirilmiştir. Elde edilen sonuçlar değerlendirildiğinde Anadolu şimşiri odununun dağınık traheli olduğu, hava kurusu yoğunluk değerinin 0,94 g/cm3 ve “ağır ağaçlar” sınıfında yer aldığı, liflere paralel basınç direncinin 70,64 N/mm2 ve “basınç direnci büyük ağaçlar sınıfında” yer aldığı belirlenmiştir. Yüzey pürüzlülük parametrelerine ait sonuçlara göre şimşir odununun radyal yüzeyinin teğet yüzeyden daha pürüzlü olduğu; renk parametrelerine ait sonuçlara göre teğet yüzeyinin radyal yüzeyden daha açık renkte olduğu ve her iki yüzeyin sarı renk tonunda olduğu belirlenmiştir. Çalışmak için sert bir oduna sahip olan Anadolu şimşiri odunu süs eşyası, alet sapları, kaşık, tarak, tavla pulu, cetvel, müzik aleti parçaları üretiminde, oymacılık, tornacılık ve kakmacılıkta yaygın olarak kullanılmaktadır. Ülkemiz ormancılığında odun dışı orman ürünü olarak alternatif tıp alanında ve süs bitkisi olarak peyzaj alanında da değerlendirilen şimşir ağaçlarının korunması ve canlılığını sürdürebilmesi için gerekli çalışmaların yapılması önerilmektedir.

Study on Attenuation Characteristics of Acoustic Emission Signals with Different Frequencies in Wood.

To study the effect of frequency on the attenuation characteristics of acoustic emission signals in wood, in this paper, two types of hard wood and soft wood were studied separately, and the energy attenuation model of the propagation process of AE sources with different frequencies was established. First, using the piezoelectric inverse effect of the AE sensor, an arbitrary waveform generator was used to generate frequency-tunable pulses in the range of 1 kHz to 150 kHz as the AE source, where the AE source energy could be regulated by the output voltage level. Then, five AE sensors were placed at equal intervals of 100 mm on the surface of the specimen to collect AE signals, and the sampling frequency was set to 500 kHz. Finally, the energy value of AE signal of each sensor was calculated based on the AC principle, and the energy attenuation model was established by exponential fitting. The results showed that both the amplitude and energy of the AE signals of different frequencies showed negative exponential decay with the increase of propagation distance, and, at the same frequency, the change of AE source energy level had no significant effect on its attenuation rate. Compared with hard wood, the energy attenuation of the AE signal of soft wood was more sensitive to the change of frequency, and, at the same frequency, the attenuation rate of soft wood was smaller than that of hard wood.

The genus Crataegus (Rosaceae) in Armenia (an updated review)

The Rosaceae family plays a leading role in the dendroflora of Armenia. The Pyrus, Sorbus, Crataegus, Cotoneaster, Rubus and Rosa genera representing the family are of great importance in Armenia in the formation of various plant coexistences. With its species composition and taxonomic diversity, Crataegus is one of the largest genera in the Rosaceae family. Growing in Armenia in low, medium and high mountain zones, Crataegus has a great role in the formation of dendroflora: they are an important element of a number of forest coexistences, form a sub-forest with other representatives of dendroflora, grow in arid sparse forests, scrub, shoreline areas of mountain rivers. Crataegus is a valuable plant resource. Some species produce tasty and nutritious fruits that are rich in sugars, organic acids, mineral salts and vitamins. Since ancient times, the people of Armenia have used it in food and folk medicine, for example there is a decoction of hawthorn root and bark dyed threads. Currently, Crataegus has great economic importance. Drought-resistant and frost-resistant species are used as grafts for obtaining high-value varieties of apple, pear, and quince, decorative species are suitable for greening cities and settlements, creating living fences. Furniture and carpentry tools are made from its hard and strong natural wood. Due to their hardiness, some species of Crataegus are promising for the creation of arid arboretums in the lower and middle mountain zones of Armenia. In Armenia the genus Crataegus is represented by 23 species belonging to three sections: Crataegus, Pentagynae C. K. Schneid. and Azaroli Loud. Species C. ulotricha Pojark. ex Gladkova, C. razdanica Pojark. ex Sargsyan, C. gabrielianae Pojark. ex Sargsyan, C. susanykleinae Gabrieljan et Sargsyan and C. gregorianii Gabrielian et Sargsyan are endemic to Armenia. An updated key is provided to identify species based on new data. Altitudinal and geographical distribution of species, habitat, flowering and fruiting time are given.

Experimental investigation on Defluoridation Competency of mesoporous Prosopis juliflora wood based biomaterials

Wood is a flexible material appreciated extremely for its, low cost, great quantity, natural composition and biocompatibility. From the present investigation, the hard wood of Prosopis juliflora is cost effective, easily disposable, biodegradable and readily available biomaterial can effectively discharge the fluoride from contaminated groundwater. In average of 20 mm × 20 mm x 6 mm sized hard wood can effectively filtered at the rate of 250–500 ml per hour. The collected 100 samples were allowed to perform different physical and chemical properties like pH, TH, TDS, EC, HCO3−, Mg2+, Cl−, Ca2+, SO4−, Na+, K+, NO3− and F−. From the obtained results, the elimination of fluoride from groundwater was achieved. Around 60 min of contact time eliminates around 97.50% and 95% of removal was achieved by agitation speed at 500 rpm. The effective removal of fluoride from contaminated groundwater would be observed around 97.8% was achieved by using Prosopis juliflora mesoporous hard wood. It is a preliminary evidence an effective for point of use to treat fluoride contaminant groundwater.

Preparation of Healable Shellac Microcapsules and Color-Changing Microcapsules and Their Effect on Properties of Surface Coatings on Hard Broad-Leaved Wood Substrates

In order to protect the wood surface and improve the properties of coatings, microcapsules with healable and discoloration functions are produced, and their healable function is obtained using shellac, which can be cured at room temperature, as the repairing agent. In this paper, self-made shellac microcapsules and color-changing microcapsules were added to varnish in different proportions to form the composite coating on a wood board, and the color difference of the coating was measured at different temperatures to study the influence of microcapsules on the degree of surface color on the substrate. The effect of microcapsules on the healable performance of coatings on a wood board was studied by scratching the surface of the coating with a utility knife and observing the process of repair. The optimal sample was selected from the orthogonal experiment for the independent experiment. The surface roughness, hardness, infrared spectrum, and scanning electron microscopy of the optimal sample were tested, and the content in the optimal sample was further investigated. The results show that color-changing microcapsules have a color-changing effect on surface coatings based on wood boards, and shellac microcapsules inhibit the color-changing effect of color-changing microcapsules. Composite microcapsules can repair the cracks on the surface coatings of wood boards. In cases where shellac microcapsules can self-repair the coating, the color-changing effect is best when the content of color-changing powder is 15.0%.

Sinonasal non-intestinal-type adenocarcinoma with isolate lagophthalmos and abducens nerve palsy: Case report

Abstract Sinonasal non-intestinal-type adenocarcinoma is a rare malignancy, with limited large-scale studies available in the medical literature. We present a case report of a 60-year-old male patient with sinonasal non-intestinal-type adenocarcinoma, isolate lagophthalmos and abducens nerve palsy, who had been exposed for 30 years to hard wood dust.

Alternative Raw Materials and Blending of Pulp to Improve Strength Properties

In this paper, Characterization of different unconventional pulping raw materials was carried out. The studies was done in terms of their contents in ash content, cellulose, ethanol–benzene solubility, , hollocelulose, lignin and hot water and 1% soda solubility was carried out. The use of blending of long fibered pulps with short fibered pulp is an important aspect of paper making .Morphological and Chemical nature of hard and soft wood are in many ways different from each other. Soft wood lack certain factors such as drainage, wet strength and press rolls tendency of sticking. To overcome these issues blending plays an important role. Pulp blending can be done in three distinct ways chips blending, pulp blending before beating and pulp blending after beating. Before pulp beating the properties improves the physical strength marginally. But after beating at 1500 revolutions in a PFI helps to improve the strength properties and resulted in increased pulp yields column.

PEROXIDE CELLULOSE FROM WHEAT STRAW

The stalks of wheat straw (triticum sh,), stored up in Еmеlyanovsk region of the Krasnoyarsk hand edge in the form of segment in 2–3 cm treated by the water solution of hydrogen peroxide and acetic acid with the catalytic amount of the sulfuric acid under hydromodule 6. The acetic acid is oxidated to peracetic acid, which, in turn, oxidizes lignin with forming of the dissolved products. The variable technological factors and ranges of their variation: initial concentration of the acetic acid (4–8-mol/l), hydrogen peroxide (3–5-mol/l); the sulfuric acid (0.25–0.65 mass.%); the temperature (80–90 °C) and cooking duration (240–330 min). The dependencies of the dissolved lignin part, output and whiteness of the cellulose from variable factor aproximated by the regression equations of the second order. The equations used for graphic presentation results and calculation of the optimum conditions of the process. On the leading indexes (output 49–63%, whiteness before 89%, explosive length before 8700 m, forcing through resistance before 240 кPа, tear resistance 420 mN) peroxide cellulose from wheat straw with the degree of the grind 30 °ShR does not concession by specified characteristic of the sulphate unbleached cellulose from hard wood. The possibility of the cellulose reception with high whiteness after cooking will allow in the row account to refuse from high-priced following bleaching.

Effects of Load Ratio Variation on the Safety of Timber Concrete Composite Floor

This paper presents the structural reliability appraisal of timber concrete composite floor designed in line with Eurocode 5 (2004) and Eurocode 2, (2004). Limit state expressions for timber concrete composite floor subdued to tension, bending, tension and bending, shear and compression were generated and their entailed reliability degrees were assessed. The basic variables associated with the design are considered to be random variables with their properties espoused from the previous studies. Reliability analysis was performed using reliability mothed i.e. first order reliability method (FORM) owing to assess the safety levels of the composite floor structural elements by considering six different modes of failure. The analysis comprised of different selected species of softwood, hard wood and glue laminated timber whose strength class were obtained from BS EN 338, 2008 and concrete of strength class C30 from Eurocode 2. The results obtained disclosed that safety indices decrease as the load ratio steps up that led to cut down of the strength. It was detected that timber with strength classes D70, D50 and C50 are safe against all different failure modes looked at except C50 and D50 against shear failure at load ratio of 1, 1.5 and 2. It was conclude timber of strength classes D70, D50 and C50 would reliable for the construction of composite floor i.e. timber-concrete floor.

Indentation Hardness and Elastic Recovery of Some Hardwood Species

The purpose of the study was to measure the Brinell hardness (HB) of six wood species and evaluate the ability to recover the depth of the imprint (self-re-deformation). Straight-grain clear samples of ash, beech, alder, birch, iroko, and linden wood were prepared. Measurements were made in the three main reference timber cross-sections: radial (R), tangential (T), and axial/longitudinal (L) and with two measuring loads of 30 kG and 100 kG (294.2 N and 980.7 N). The tested wood species could be classified into hard (ash, beech), medium-hard (alder, birch, iroko), and soft (linden) wood species. The HBs of each tested wood species differed in the cross-sections, i.e., side hardness (R, T) and end hardness (L). Higher HB values were obtained at 100 kG load in all species and all three cross-sections. The lowest influence of the measurement force value on the HB value was revealed for the soft wood species (linden: 107–118%). This influence was visible for the other five medium-hard and hard wood species, ranging from 125% to 176%. The percentage of temporary imprint in total imprint depth (x/H) varied from 12 to 33% (linden 12–18%—the lowest self-re-deformation ability; beech 25–33%—the highest self-re-deformation ability). The results of this study underline that the higher the density of the wood, the higher the Brinell hardness, and, simultaneously, the greater the measurement force used, the higher the Brinell hardness measured. The ability of self-re-deformation in wood’s R and T cross-sections depends on the wood density and the measuring force used. In contrast, this ability only depends on the wood density in the L cross-section. Those observations imply that the compaction of the cell structure during side compression is mainly non-destructive, while the longitudinal deformation of the cell structure (the buckling of cell walls and fracture of ends of the cells) is to a great degree destructive and irreversible. These results can be used in the construction and furniture sectors, especially when designing products and planning the woodworking of highly loaded wood floors and furniture elements.

Carbon conundrums: Do United States' current carbon market baselines represent an undesirable ecological threshold?

Relative frequency distribution of observed annual mortality expressed in aboveground (AG) carbon (C) (Mg CO2 e ha-1 year-1 ) summarized across supersections by forest type [Hardwood (HW) vs. Softwood (SW)] and site class (Low vs. High) based on approximately 130,000 remeasured USDA Forest Service Forest Inventory and Analysis plots across the US. Top panel summarizes conditions in plots that do and do not meet the California Air Resources Board standards based on total basal area, whereas bottom panel summarizes conditions in plots falling inside and outside of optimum relative density levels. The latter represents a biophysically-informed approach accounting for changes in tree (and carbon) packing over forest development.

Process Simulation-Based Life Cycle Assessment of Dissolving Pulps.

Dissolving pulp (DP) is a specialty pulp product from a variety of lignocellulosic biomass (i.e., hardwoods (HW) and softwoods (SW)) with a broad range of applications. Conducting life cycle assessment (LCA) for DP end applications (e.g., textile products, specialty plastics) is challenging due to the lack of life cycle inventory (LCI) data and environmental information associated with different grades. This research addresses this challenge using process simulations to generate LCI for different DP grades (e.g., acetate and viscose) made from HW and SW, respectively. The LCA results show that biomass feedstock directly affects the environmental impacts of DP. For instance, HW acetate grade has higher global warming potential than SW acetate but lower environmental impacts in other categories related to ecosystems and human health. This HW versus SW comparison has similar results for viscose DP in all impact categories except eutrophication. Additionally, a hotspot analysis identifies that on-site emissions and chemicals are the main contributors to the environmental impacts across all grades in this study. The results and LCI data generated in this work provide critical information to support future LCA and sustainability assessment for end-products derived from DP.

Social and Ecological Factors Affect Long-Term Resilience of Voyaging Canoes in Pre-contact Eastern Polynesia: A Multiproxy Approach From the ArchaeoEcology Project

While Eastern Polynesian archaeologists rarely recover archaeological remains of canoes (va‘a), ethnohistoric texts document how such vessels played a central role in the daily lives of commoners and chiefs alike. Here, we refocus discussions of va‘a in Polynesian societies through synthesizing proxy information (archaeological data, evidence from ethnographic and ethnohistoric sources, ecological modeling, human-centered interaction networks) on canoe use in the Society Islands of French Polynesia. While all communities who initially settled Eastern Polynesia archipelagoes must have done so with large double-hulled canoes, their use was absent in some societies by the time of European contact. We question why some Eastern Polynesian societies retained the use of large ocean-going canoes, while others did not. For high island archipelagoes like the Society Islands, sources document how large double-hulled canoes facilitated and supported elite intra-archipelago voyaging, warfare, and exchange with near and remote hinterlands up until European contact in the mid-eighteenth century. While smaller canoes were used by commoners on a daily basis for subsistence fishing and island-wide transport, larger ocean-going canoes were strictly the purview of high-ranking elites. Our human-centered interaction network models help us to identify how social processes put constraints on the manufacture and continued use of large ocean-going va‘a in Eastern Polynesian contexts. We deploy such data to outline steps in the production, use, and re-use of canoes. We employ network science to better understand the relationships between animal and plant species used by the Mā‘ohi in canoe manufacture, quantifying the number of resources used, the number of social personae involved, and the amount of labor/energy involved in their manufacture. Finally, we use Mo‘orea settlement pattern data, as well as landscape and elevation data, to visually model the extent to which local ecologies or habitats constrained access to long-lived hard wood trees, key raw materials in the construction of ocean-going vessels. We consider the additional variables of soil pH and tree regrowth rates in our modeling of the ecological limits of preferred va‘a species. We then query differential patterns of continued use of ocean-going vessels in two Eastern Polynesian archipelagoes: the Gambier archipelago and the Society Islands. Utilizing these multiple sources of data, we return to the age-old question of what roles social and natural processes played in the resiliency of the socio-political systems of Polynesian chiefdoms. We view ocean-going canoes as critical social tools in terms of resilience, as use of these water craft reduced island isolation and allowed for contact with near, and sometimes far, neighbors who served as critical buffering agents, particularly in times of ecological crises, such as drought, famine, or tsunamis.

The use of thermo electric generator to utilize the waste heat from the biomass stove into electricity

Indonesia has a huge potential for biomass energy resources. In 2013, the estimated potential of forest biomass in Indonesia for bioenergy was 132 PJ, 50.4% from harvest residues and 49.6% from wood processing residues. Until now, the technology of burning biomass using a stove continues to develop. Biomass stoves are designed, modified and tested to get maximum performance, at least approaching the performance of LPG-fueled stoves. Several studies concluded that about 14.66% of the total heat loss is on the walls of the biomass stove. The purpose of this study was to investigate whether the waste heat in the wall of a biomass stove can be used to generate electricity. Many researchers have studied the heat loss on the walls of the biomass stove, this heat loss can reduce the thermal efficiency of the stove and can cause the stove user to feel uncomfortable. Based on the Seebeck effect method where the temperature difference can be converted into electricity. If there is a temperature difference between the two sides of the thermoelectric, electricity will arise. This principle is used by thermoelectric generators. To maximize the temperature difference, the cold side of the Thermoelectric Generator (TEG) needs a cooling system. In this study, the TEG was attached to the wall of the biomass stove, then the voltage generated by the TEG was measured for each type of biomass fuel. the highest average voltage produced by wood chips, followed by candlenut shells, corn cobs and coconut shells. This is unique, although the calorific value of coconut shells (19,5 MJ/kg) is higher than hard wood (18,8 MJ/kg) and corn cobs (5.32 MJ/Nm3 ), but the highest average voltage is produced by wood 1.30 volts, then 1.12 volts of candlenut shells, 1.08 volts of corn cobs, and 0.79 volts of coconut shells.

Evaluation of physical and electrochemical performances of hardwood and softwood derived activated carbons for supercapacitor application

This study is conducted to perceive evaluation of physical and electrochemical performances between activated carbons (ACs) derived from hardwood (HW) and softwood (SW). Here, ACs (HW-AC and SW-AC) are prepared by applying a cheap and easy-to-prepare method via chemical impregnation of H3PO4 at one-step integrated high-temperature carbonization process. The prepared HW-AC reveals large specific surface area of 1291.4 m2g−1 with 3.6 nm of pore size, which are larger than those of SW-AC having 1024.3 m2g−1 of specific surface area with 2.0 nm of pore size. However, both ACs do not exhibit high electrochemical properties. Therefore they are composited with MnO2 in three ratios of AC to MnO2 (1:1, 1:2 and 2:1) which resulted in remarkably enhanced electrochemical performances. Among the three composites, 1:1 hybrid-composite of HW-AC exhibits best electrochemical performances with specific capacitance of 484.3 Fg−1 at current density of 1 Ag−1, cycle life of 98.3 % (1000 cycles at 3 Ag−1) and specific energy density of 24.2 Whkg−1 at specific power density of 150.4 Wkg−1 in 6 M KOH electrolyte in 3 electrode set-up in a working voltage of 1.2 V. While, there is a significant improvement in performances of 1:1 hybrid SW-AC as compared to only SW-AC. It shows the specific capacitance of 309.2 Fg−1, cycle life of 94.3 % and specific energy density of 16.8 Whkg−1 at specific power density of 148.4 Wkg−1 related to specific capacitance of 104.3 m2g−1, cycle life 83.3 % and specific energy density of 2.3 Whkg−1 at specific power density of 79 Wkg−1 of SW-AC. The findings have been interpreted based on the lignocellulosic content of the precursors.

The Effect of Wood Type on the Reflection of a Table Tennis Ball

The table tennis game table can be made of any material with certain bounce height requirements according to ITTF regulations. Wood as the main material for the table is found in Indonesia. Various types of wood have the potential to be a dining table material. This study was conducted to determine the effect of the type of wood on the bounce of a table tennis ball. Experiments were carried out on 9 types of wood, namely hardwoods (teak, sono, coconut), medium hardwoods (meranti, plywood and jackfruit) and soft woods (waru, randu and sengon). The height of the falling ball is determined to be 30 cm for the ball's bounce recorded by the camera. The ball used is a ball with a weight of 24 grams and 30 grams. Camera recording data is processed with Kinovea 08.15 to get the reflection height. The bounce height is used as a reference for ITTF standard compliance. The initial height and reflection height were then used to calculate the coefficient of restitution (COR). Data collection was carried out 5 times and the average value was calculated. The level of wood hardness is influenced by its specific gravity. Hard wood has a relatively high specific gravity. Teak wood which is relatively hard has a specific gravity value of 0.59 – 0.82 gr/cm3