Woodcuts Research Articles

Dielectric and physico-chemical behavior of single thermally thick wood blocks under microwave assisted pyrolysis

Pyrolysis of thermally thick beech wood blocks with a size of around 2.5 × 8 × 6 cm3 (width × length × height) was carried out in a lab scale microwave reactor with a frequency of 2.45 GHz, operated, both, at 300 W and 600 W under inert conditions, using N2 at around 400 mbar absolute pressure. The microwave cavity had a size of 20 × 20 × 20 cm3. The specific energy supply referred to the untreated wood block was 4–8 W/g, with slight variations depending on the initial water content. The mass loss and the reflected microwave power were in-situ monitored during the experiments. The sample surface and chamber temperatures were measured with a pyrometer and a thermocouple, respectively. Physico-chemical and dielectric properties of the produced solids were investigated and compared to those of chars produced under conventional pyrolysis using the same raw materials. It is shown that the complex dielectric permittivity of the solid products changed drastically during the pyrolysis process, with increasing heating properties as the conversion process evolved. This was easily achieved using 600 W without susceptors. However, 300 W was not enough to achieve a high conversion degree, independently of the irradiation time. This, together with the physico-chemical analyses of the solids, hinted to the importance of the transport kinetics in thermally thick materials, although further investigation is still required.

Compressive behavior of damaged timber columns: Experimental tests, degradation model, and repair method

Local decay often appears in columns of traditional timber structures and negatively affects their compressive behavior. In this study, axial compression tests were conducted on four column specimens with different damage degrees, which were simulated by artificially removing local wood, and on three damaged column specimens that were reinforced by filling with different wooden blocks to investigate the degradation performance and repair ability of timber columns. The failure mode, load-axial displacement curves, load-lateral deflection curves, varied load-carrying capacity laws, and different stiffness of the locally damaged and repaired timber columns were obtained and analysed. The study results indicated buckling failure was observed on all column specimens. The compressive strength and stiffness decreased significantly with an increase in the damage degree for the locally damaged timber columns. Moreover, a theoretical degradation model was proposed to predict the compression strength of locally damaged timber columns, and a good agreement was obtained between the theoretical and experimental results. This degradation model can provide a theoretical basis for evaluating the compression behavior of damaged timber columns. For repairing timber columns, the local damage section can be filled with a wooden block; the larger the length and elastic modulus of the block, the better the repair effect. The compression behavior of the damaged timber columns repaired using the optimized wooden block could restore to that of the intact timber column.

High-performance and scalable wood-based solar-driven interfacial evaporator with corrugated structure for continuous desalination

Interfacial solar-driven evaporation of saline water is a promising technique that enables worldwide upscaling of freshwater with a minimum of carbon footprint. For this purpose, wood is demonstrating a desirable substrate due to its high porosity and low thermal conductivity. Despite much effort has been dedicated to improving the performance of wood evaporators, their scalability and reliability still restrict applications. Here we present a large-scale and highly-efficient wood-based evaporator with corrugated sheet structures using a facile mechanical processing strategy that utilizes the excellent processability of wood. The corrugated structure of the longitudinal wood block, transports water in the longitudinal direction and thereby increases the evaporation area. With the inclusion of a Chinese ink layer and hydrophobic treatment, the prepared wood-based evaporators exhibit a high evaporation rate (1.77 kg m−2 h−1 for spruce wood, 1.42 kg m−2 h−1 for beech wood) and efficiency (111.53% for spruce wood, 88.73% for beech wood) at 1 sun irradiation and continuous water desalination, which is superior to both reported longitudinal and most transverse wood-based evaporators. This work demonstrates a universal and economy strategy for preparing large-sized wood-based solar evaporators with processability, stable performance and high efficiency.

Biological control of some wood-decay fungi with antagonistic fungi.

One of the most important biological factors that damage wood materials are wood-decay fungi (WDF). Chemical preservatives have traditionally been the most effective method for controlling WDF. However, due to environmental pressures, scientists are working on alternative protection methods. The aim of this study was to investigate the potential of some antagonistic fungi against wood-decay fungi as a biological control agent (BCA). For this purpose, the antagonistic effects of Trichoderma harzianum, Trichoderma viride, Aspergillus niger, and Penicillium brevicompactum fungi were investigated against the Trametes versicolor, Trametes hirsuta, Stereum hirsutum, Coniophora puteana, Neolentinus lepideus, and Postia placenta species of wood-decay Basidiomycetes fungi. In the study, firstly, inhibition rates were determined by comparing dual culture tests on agar medium, and then the performance of BCAs was compared by performing decay tests on wood blocks. As a result of the study, it was determined that the species belonging to the genus Trichoderma showed a very effective performance on WDF, increased the inhibition rate to 76-99%, and reduced the weight loss to 1.9-5.8%. Considering the inhibition rates, it was determined that the most effective rate of the BCAs was on P. placenta and the least on S. hirsutum species. According to the results obtained, it has been determined that some BCAs were very effective biological control agents of rot fungi on agar and wood blocks in vitro. However, in order to more clearly determine the effectiveness of BCAs in practice, this study, which was carried out in the laboratory environment, should be supported by tests performed in contact with the external field and soil.

Wood Coloration and Decay Capabilities of Mycoparasite Scytalidium ganodermophthorum.

Scytalidium ganodermophthorum (telomorph: Xylogone ganodermopthora) Kang, Sigler, Lee & Yun is a destructive fungal pathogen that produces a yellow pigment that is used in sustainable product development. Similar pigmenting ascomycetes cause soft rot in woody substrates, however, the decay capabilities of S. ganodermophthorum have not been assessed or related to pigment production. A wood block decay test showed highly variable production of the expected bright yellow pigment and a secondary darker pigment when tested against multiple wood species and nutrient conditions. Microscopic examination showed cell wall erosion typical of type-2 soft rot in wood, although enzymatic analysis did not show detectible levels of endocellulase. Chitinase was detected in plate cultures but not wood cultures, indicating adaption of the fungus to a variety of environmental growth conditions. The high variability of pigmentation in wood cultures suggests that growth of S. ganodermophthorum on liquid media and use of extracted pigment is a superior method for obtaining consistent yellow coloration.

Pengembangan Media Jenga Aksara Jawa dalam Pembelajaran Membaca dan Menulis Teks Berhuruf Jawa

Abstract
 There was no development of Javanese script learning media impacted with the less interesting and ineffective learning process so that students have difficulty in understanding Javanese script material. This study aimed to describe the students and teachers’ needs for Javanese script learning media, describe the prototype of the Javanese script Jenga media, and describe the results of the validation of media and material experts on the Javanese script Jenga media. The method of this study used Research and Development. Then, in collecting data this study used interview and questionnaire techniques. The data collected were analyzed using descriptive qualitative and quantitative descriptive analysis techniques. Based on the results of this study, it can be seen that students and teachers need an interesting and effective learning media to help them easier in understanding Javanese script material. The prototype of the Javanese Script Jenga media consists of a media box, Javanese Script Jenga wooden block, cards and their boxs, dice, blackboard, markers, students’ guidebook, and teacher's manual handout with practice questions and answer keys. Based on the assessment result, Jenga Aksara Jawa media prototype obtained an assessment percentage of 80% from media experts and 77.6% from material experts. Expert validators also provided suggestions and input that can be received into consideration by researchers to improve the Javanese script Jenga media prototype shortcomings. Therefore, this Javanese script media is proper to be used as a learning media with improvements according to the suggestions.

Long-term fungal inoculation of Ficus sycomorus and Tectona grandis woods with Aspergillus flavus and Penicillium chrysogenum

In the current study, two molds, Aspergillus flavus (ACC# LC325160) and Penicillium chrysogenum (ACC# LC325162) were inoculated into two types of wood to be examined using scanning electron microscopy-energy dispersive X-ray (SEM–EDX) and computerized tomography (CT) scanning. Ficus sycomorus, a non-durable wood, and Tectona grandis, a durable wood, were the two wood blocks chosen, and they were inoculated with the two molds and incubated for 36 months at an ambient temperature of 27 ± 2 °C and 70 ± 5% relative humidity (RH). The surface and a 5-mm depth of inoculated wood blocks were histologically evaluated using SEM and CT images. The results showed that A. flavus and P. chrysogenum grew enormously on and inside of F. sycomorus wood blocks, but T. grandis wood displayed resistance to mold growth. The atomic percentages of C declined from 61.69% (control) to 59.33% in F. sycomorus wood samples inoculated with A. flavus while O increased from 37.81 to 39.59%. P. chrysogenum caused the C and O atomic percentages in F. sycomorus wood to drop to 58.43%, and 26.34%, respectively. C with atomic percentages in Teak wood’s C content fell from 70.85 to 54.16%, and 40.89%, after being inoculated with A. flavus and P. chrysogenum. The O atomic percentage rose from 28.78 to 45.19% and 52.43%, when inoculated with A. flavus and P. chrysogenum, respectively. Depending on how durable each wood was, The examined fungi were able to attack the two distinct types of wood in various deterioration patterns. T. grandis wood overtaken by the two molds under study appears to be a useful material for a variety of uses.

FOLL-E: Teaching First Order Logic to Children

First-order logic (FO) is an important foundation of many domains, including computer science and artificial intelligence. In recent efforts to teach basic CS and AI concepts to children, FO has so far remained absent. In this paper, we examine whether it is possible to design a learning environment that both motivates and enables children to learn the basics of FO. The key components of the learning environment are a syntax-free blocks-based notation for FO, graphics-based puzzles to solve, and a tactile environment which uses computer vision to allow the children to work with wooden blocks. The resulting FOLL-E system is intended to sharpen childrens' reasoning skills, encourage critical thinking and make them aware of the ambiguities of natural language. During preliminary testing with children, they reported that they found the notation intuitive and inviting, and that they enjoyed interacting with the application.

Perancangan Alat Penentuan Koefisien Gesek Statis Menggunakan Sensor IR FC-51 dan Potensiometer Berbasis Arduino Uno

An Arduino Uno-based static friction coefficient (µs) determination tool equipped with an IR sensor module FC-51 has been created. This µs determination tool is made to reduce the possibility of observation errors when doing physics labs. The µs determination tool consists of an FC-51 IR sensor component to detect precisely when an object is moving. The potentiometer measures the angle of the base surface, and an Arduino Uno device transmits data from the hardware to the computer in real time. The work test of the µs determination tool starts with the base surface with a slope of 0o, and then the object is placed on the base surface and precisely above the surface of the FC-51 IR sensor. When the base surface is tilted slowly, the potentiometer also rotates, showing the plane angle's size. As long as the object is not moving, the IR FC-51 sensor is in low condition. When the object moves, the IR FC-51 sensor is in high condition. The change in signal from low to high indicates that the object is moving when the plane reaches the slope angle, and the slope angle shows the value of µs. The µs are measured on a wooden base with wooden blocks and a glass base with glass blocks. The results obtained for a wooden base with wooden blocks µs = 0.73 with an average slope angle = 36.16o and a glass base with glass blocks µs = 0.4 with an average slope angle = 22.1o. The results show that the µs level of the wood surface with wood is greater than the µs level of the glass surface with glass.

Persistence of orthopaedic hoof blocks for the treatment of lame cattle kept permanently at pasture

ABSTRACT Aims To compare the retention by New Zealand dairy cows kept at pasture in a lame cow group, of three hoof block products commonly used in the remediation of lameness. Methods Sixty-seven farmer-presented Friesian and Friesian x Jersey dairy cows from a single herd in the Manawatū region (New Zealand) suffering from unilateral hind limb lameness attributable to a claw horn lesion (CHL) were randomly allocated to one of three treatments: foam block (FB), plastic shoe (PS) and a standard wooden block (WB). Blocks were applied to the contralateral healthy claw and checked daily by the farm staff (present/not present) and date of loss was recorded. Blocks were reassessed on Day 14 and Day 28 and then removed unless further elevation was indicated. Daily walking distances were calculated using a farm map and measurement software. Statistical analyses included a linear marginal model for distance walked until block loss and a Cox regression model for the relative hazard of a block being lost. Results Random allocation meant that differences between products in proportion used on left or right hind foot or lateral or medial claw were small. Mean distance walked/cow/day on farm tracks whilst the block was present was 0.32 (min 0.12, max 0.45) km/day; no biologically important difference between products in the mean distance walked was identified. Compared to PS, cows in the WB group were five times more likely to lose the block (HR = 4.8 (95% CI = 1.8–12.4)), while cows in the FB group were 9.5 times more likely to lose the block (HR = 9.5 (95% CI = 3.6–24.4)). Conclusions In this study, PS were retained for much longer than either FB or WB. As cows were managed in a lame cow group for the study duration, walking distances were low and did not impact on the risk of block loss. More data are needed to define ideal block retention time. Clinical relevance In cows with CHL the choice of block could be based on the type of lesion present and the expected re-epithelisation times.

Effect of soil types on root infection of Acacia mangium and Eucalyptus pellita by Ganoderma philippii and Pyrrhoderma noxium

Abstract. Indrayadi H, Glen M, Fahrizawati, Siregar BA, Rimbawanto A, Mardai, Tjahjono B, Mohammed C. 2023. Effect of soil types on root infection of Acacia mangium and Eucalyptus pellita by Ganoderma philippii and Pyrrhoderma noxium. Biodiversitas 24: 2358-2364. Acacia mangium Willd. and Eucalyptus pellita F.Muell. are susceptible to red root-rot disease, caused by Ganoderma philippii (Bres. & Henn. ex Sacc.) Bres., has led to the demise of planted A. mangium as a commercial pulpwood in Indonesia. A second root-rot pathogen, Pyrrhoderma noxium (Corner) L.W.Zhou & Y.C.Dai (syn. Phellinus noxius (Corner) G.Cunn.), also attacks both species. The objective of this study was to investigate the effect of different soil types on the root infection of A. mangium and E. pellita by G. philippii and P. noxium. The effect of three contrasting soil types (mineral R41, R51 and peat soil) used in a plantation estate in Riau province on disease development was investigated in a pot trial using four isolates, two of G. philippii and two of P. noxium. Two models of inoculation were used, in one of which inoculated wood blocks were placed against the seedling roots (Model 1), the second where the blocks were 10-20 cm from the roots (Model 2). Fifty weeks after the experiment was established, mortality was significantly higher in the soil of low than high clay content, in A. mangium than E. pellita, and in Model 1 than Model 2; there was no difference between the two G. philippii isolates, and P. noxium did not cause any mortality. G. philippii inoculum could survive in all three soil types for over 9 months; hence, the effect of soil type was not mediated by inoculum longevity. Alternatives should be pursued to limit further development of root-rot diseases in existing E. pellita estates.

Investigating the Resistance Expression Method of Wood Resistance Drill Instruments

Abstract Wood density is an important attribute that is positively correlated with many wood quality parameters. How to express wood density with drill resistance is a challenge. In this study, we determined the optimal resistance expression using the current, voltage, and power of the DC (Direct-Current) motor. Nine wood blocks crossing over the pith, with widths and heights of 2 cm and 5 cm, respectively, were obtained from three larch (Larix spp.) trees. The microdensity of each wood block at every 0.1-mm length was measured, and the average current, voltage, and power of the DC motor was recorded when the drill fed forward at every 0.1 mm by a self-manufactured resistance drill. The drill path was parallel to the lengthwise direction of the block. The linear models between the current, voltage, and power of the DC motor and wood microdensity were subsequently established, and the model with the highest R2adj was selected to express the resistance. The adjusted R2adj of the forward stepwise regression models between the current, voltage, and power of the DC motor and wood microdensity were determined as 0.2943. This suggests that the drilling needle resistance expressed with the current, voltage, and power or other combination may be optimal.

Using Growth Rings on Wooden Blocks and Plywood to Enhance Students' Spatial Reasoning Skills

Using Growth Rings on Wooden Blocks and Plywood to Enhance Students' Spatial Reasoning Skills

Stain Fungi and Discoloration Control on Rubberwood (Hevea brasiliensis Muell. Arg.) by Vacuum-Pressure Treatment with Catechin from Gambir (Uncaria gambir Roxb.)

Recently, the morphological and molecular features of five stain fungi infecting rubberwood (Hevea brasiliensis), namely Paecilomyces maximus, Paecilomyces formosus, Penicillium crustosum, Paecilomyces lecythidis and Aspergillus chevalieri, have been studied. Prior to this study, the authors revealed that catechin from gambir (Uncaria gambir) could inhibit the growth of the white-rot fungus Schizophyllum commune, and it was important to determine the bioactivity of the aforementioned agent against A. chevalieri. The efficacy of the biocidal agent was examined using a laboratory wooden block test. Rubberwood blocks, 8 mm in thickness, 20 mm in width, and 30 mm in length, were impregnated with catechin solution at concentrations of 6%, 9%, 12%, and 15% (w/v) using the vacuum-pressure method, and their bioactivity was monitored over three weeks through visual and scanning electron microscope assessment of fungal growth as well as the discoloration intensity of the wood samples. The results showed that catechin treatment increased the resistance of wood samples to A. chevalieri. Overall, the higher the catechin concentration, the lower the fungal growth. The lowest fungal growth was observed in the wood samples treated with 12% and 15% catechin (score of 0), demonstrating no discoloration. In contrast, the fungal growth score of the untreated wood samples reached 4, indicating severe discoloration. Catechins appear to be adequate biofungicides against stain fungi in rubberwood.

Evaluating the Performance of an Arduino-Controlled Wood Scaling Machine

The aim of this quantitative study was to evaluate the performance of an Arduino-controlled wood scaling machine, designed to improve the cutting process for woodwork and furniture production. The machine was developed with the goal of achieving accuracy, precision, and consistency in wood cutting, while also reducing the need for time-consuming grinding and polishing. The wood cutter machine was composed of a circular saw, relay, conveyor, and control module, with the added feature of an Arduino for automated scaling. The study found that the machine's performance was more reliable, effective, and safer than other wood cutting machines, and its use could lead to faster, better, and more accurate cuts. The wood scale cutter machine was also designed to be more affordable while maintaining a standard quality that would ensure its longevity for years. The results of this study offer an innovative and improved wood cutting tool that could compete in the market and benefit workers by reducing working time and increasing productivity.

Testing of a custom, portable drill press to minimize probe misalignment in sap flow sensors.

The accurate estimation of plant transpiration is critical to the fields of hydrology, plant physiology and ecology. Among the various methods of measuring transpiration in the field, the sap flow methods based on head pulses offers a cost-effective and energy-efficient option to directly measure the plant-level movement of water through the hydraulically active tissue. While authors have identified several possible sources of error in these measurements, one of the most common sources is misalignment of the sap flow probes due to user error. Though the effects of probe misalignment are well documented, no device or technique has been universally adopted to ensure the proper installation of sap flow probes. In this paper we compare the magnitude of misalignment errors among a 5mm thick drilling template (DT), a 10mm thick DT, and a custom designed, field-portable drill press. The different techniques were evaluated in the laboratory using a 7.5cm wood block and in the field, comparing differences in measured sap flow. Based on analysis of holes drilled in the wood block, we found that the portable drill press was most effective in assuring that drill holes remained parallel, even at 7.5cm depth. In field installations, nearly 50% of holes drilled with a 5mm template needed to be redrilled while none needed to be when drilled with the drill press. Widespread use of a portable drill press when implementing the heat pulse method would minimize alignment uncertainty and allow a clearer understanding of other sources of uncertainty due to variability in tree species, age, or external drivers or transpiration.

Fungal Resistance and Leaching Behavior of Wood Treated with Creosote Diluted with a Mixture of Biodiesel and Diesel

This study evaluated the effect of biodiesel as a co-solvent with the wood preservative creosote to reduce the amount of hydrocarbon-based carrier utilized. Small blocks of wood were treated at a pilot scale using three different creosote concentrations. The diluent used was a blend of 80% soybean biodiesel and 20% petroleum diesel. The efficacy of creosote was tested against brown rot and white rot fungi. The results of the wood-block test and agar test suggested that there was no significant effect of biodiesel on the efficacy of creosote as a wood preservative. As creosote-treated wood is commonly used for railway ties, its potential impact on the surrounding environment was also assessed by studying the leaching behavior of creosote–biodiesel–diesel blend treated railway ties. Rainfall simulators were used to imitate an exposure of treated wood to a significant amount of rainfall. Wood core drilled from the exposed railway ties and leaching water samples were analyzed for the levels of polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs). Overall, this study demonstrated that the diluent containing biodiesel had no negative effect on the performance of creosote as a wood preservative and towards the natural environment.

Colonization and confrontation of four Armillaria sinapina isolates to Armillaria ostoyae within inoculated wood blocks and stumps

Roots represent a third of terrestrial biomass. After logging, fungal pathogens use stump roots as a food base to survive and this may result in negative impact on aboveground plant production. Mycelial spread determines the fungal volume in the stump, which in turn dictates inoculum potential and spread distance; hence, it is a key disease factor. The current study focuses on the spread and confrontation of two sympatric species of Armillaria with differing virulence. Living cut blocks of Douglas-fir stem were inoculated at opposite ends with a virulent Armillaria ostoyae isolate, or four A. sinapina isolates with low virulence from two biogeoclimatic zones. The inoculum blocks were buried in moist sand, and then the surface area and volume occupied by each was determined. The drier zone A. sinapina isolates colonized 80% of the block surface areas, while the moister zone isolates were about equal with A. ostoyae (42% colonized). Additionally, inoculum blocks of each species were buried against a root and root collar of two living trees, the trees were cut, and the stumps became colonized. One stump had greater A. ostoyae colonization over A. sinapina by 12%, and the other larger stump by 74% because of thicker root collar bark that hindered A. sinapina. All interspecific encounters produced a stalemate. Increased growth potential of A. sinapina in drier zones might enable root colonization before drying. Southern Canada is forecast to become drier and warmer, favouring A. ostoyae over A. sinapina in the currently more productive areas, with an increasing negative impact on aboveground productivity.

Durability of Hinoki (Chamaecyparis obtusa) stained wood following Anaglyptus subfasciatus infestation

Abstract The Japanese longhorn beetle, Anaglyptus subfasciatus, infests coniferous trees resulting in stained wood and low-value discolored lumber. In this study, the discolored Hinoki (Chamaecyparis obtusa) wood was analysed by GC-MS for n-hexane extract, and laboratory wood block tests against termite was carried out. Stained wood had anti-termitic resistance similar to normal heartwood, and it had about twice the n-hexane extract by weight than obtained from heartwood. One compound, nerolidol, was characteristically found in the stained wood. The results suggest that the stained wood may have produced some bioactive components due to damage by wood decay organisms.

A hybrid nanogenerator for collecting both water wave and steam evaporation energy

Water is an important resource for building different energy systems towards diversified applications. In this paper, a novel hybrid nanogenerator is proposed based on a water-wave triboelectric nanogenerator (TENG) and evaporation generator, which opens up a more effective approach to fully utilize the energy from water. This hybrid nanogenerator can solve the problem of insufficient output of water wave TENGs in calm water. The optimized peak power of water-wave TENG can reach 0.62 mW under simulated waves frequency of 2.5 Hz, while a capacitor of 0.33 µF can be charged to 15 V by TENG within 80 s in actual water waves. The evaporation generator based on wood block can continuously generate direct currents during the spontaneous evaporation of water. The solar-vapor conversion efficiency of evaporation generator can reach 84.2%, while the evaporation generator can provide a maximum current density of 3.2 μA·cm−2 and a maximum output power density of 1.4 mW·m−2 with a matching load of 10 kΩ (23 ℃, 30% RH). To demonstrate the application capability of the evaporation generator, we design a multi-stage boost circuit coupled with the pulse charging method, which can increase the voltage output and effectively reduce the charging time. The proposed hybrid nanogenerator provides a promising way for collecting both water wave and steam evaporation energy, effectively broadening methods for energy harvesting by TENGs.