Outer Bark Research Articles

Machinability characteristics study on hibiscus rosa-sinensis reinforced polymer composites using soft computing techniques

Abstract Understanding the drilling behaviour of composite materials is crucial for optimizing their manufacturing processes and enhancing their applicability across various industries. In this study, the drilling process of Hibiscus Rosa-Sinensis Polymer matrix composites is investigated due to the significance of investigating such advanced and sustainable composite materials for their potential applications. Hibiscus Rosa-Sinensis Fibers are extracted and processed from the outer bark of the hibiscus plant, are incorporated into polymer matrices in varying weight percentages (0 Wt%, 10 Wt%, 20 Wt%) to form discontinuously reinforced polymer composites. Samples with uniform dimensions of 150 × 75 × 15 mm, are used for the drilling operation using Ace Micromatic DTC-400 instrument. The project focuses on analysing the influence of key drilling input parameters such as Spindle speed, Feed rate and HRS (Hibiscus Rosa-Sinensis) Fiber weight percentage on the Thrust Force (N) and Torque (N-m) generated during drilling operations. Taguchi’s Design of Experiments with L27 orthogonal array is used to systematically optimize the input parameters to gain insights into the drilling behaviour of these composite materials. Further a second order mathematical model has been generated for Thrust Force and Torque using Response Surface Methodology (RSM). Thrust Force and Torque during drilling are measured using 9257 BA KISTLER Dynamometer coupled with DynoWare 2825 A software. The findings of this study not only contribute to a deeper understanding of the drilling process but also hold significant implications for industries reliant on composite materials. From aerospace to automotive sectors, where lightweight and durable materials are essential, to construction and renewable energy industries seeking sustainable alternatives, the application potential of hibiscus Rosa-Sinensis Fiber-reinforced composites is vast. By elucidating the intricate dynamics of drilling operations on these materials, this research paves the way for enhanced manufacturing processes and the development of advanced composite structures tailored to meet the demands of diverse industrial applications.

Leveraging Spruce Bark Particle Morphology for Enhanced Internal Bonding in Particleboard Production.

The continuous rise in global demand for wood products has led to an increase in prices and a surge in research into alternative resources. As a byproduct of the timber industry, bark has emerged as a promising supplement in particleboard (PB) production. However, its anatomical structure, the presence of extractives, and its inferior mechanical properties complicate the production process, which have not yet been fully overcome at a commercial scale. This study proposes a paradigm shift, advocating for separate and specialized bark constituent processing in a wet state. Three bark-based raw materials-namely, outer bark particles, bark fiber clumps, and bark fibers-were investigated under varying wood content scenarios. PBs with a target density of 0.7 g/cm3 and a thickness of 16 mm were produced using mixtures of these bark-based materials and wood particles in different ratios bonded with a urea-formaldehyde adhesive. The results demonstrated that these bark constituents exhibit distinct properties that can be optimized through tailored processing techniques. Compared to bark fibers, outer bark particles displayed about 40% lower water absorption and thickness swelling. However, bark fibers improved the internal bond by about 50% due to their favorable morphology compared to outer bark. These findings highlight the potential of bark as a valuable resource for particleboard production and pave the way for its efficient utilization through specialized processing strategies.

Used in Urban Area for Landscape Planning and Design Spatial and Temporal Variations in Chromium (Cr) Concentrations in Picea orientalis L.

This study investigates the spatial and temporal variations in chromium (Cr) concentrations in Picea orientalis L., across different directions (north, east, south, and west) and plant organs (outer bark, inner bark, and wood) in a forested region. The research, conducted over eight age periods spanning 1980 to 2020, aimed to assess the effectiveness of Picea orientalis L. as a biomonitor for Cr pollution. The highest Cr concentrations were observed in the east direction, particularly in the inner bark and wood, while the lowest levels were found in the west. The study was conducted in an urban area near the industrial zone and highway, as well as in forested regions. A total of 100 trees were selected for the study, with samples collected from three different organs: outer bark (OB), inner bark (IB), and wood. Samples were taken from each organ at breast height (approximately 1.3 meters above the ground) to ensure consistency. The sampling covered various age periods, specifically 1980–2020, to analyze temporal changes in Cr concentrations. Statistical analysis revealed significant variations in Cr concentrations across most directions and periods, with notable increases during certain periods, especially in the west direction. These variations can be attributed to several factors, including the proximity to industrial sources of pollution, which typically release higher levels of chromium into the environment. The eastern direction likely experiences greater exposure to these emissions due to prevailing wind patterns and urban runoff, leading to increased accumulation in Picea orientalis L. Additionally, seasonal changes, temperature fluctuations, and soil characteristics may influence the bioavailability of chromium, affecting its uptake by the tree. The results suggest that Picea orientalis L. can effectively reflect Cr pollution levels, with significant directional and temporal variations that highlight the influence of these environmental factors on Cr accumulation. This study underscores the potential of Picea orientalis L. as a valuable tool for monitoring and managing Cr pollution in forested environments.

Valorizing Biopolyester Suberin: Modification of Cellulose Nanocrystals and Performance Assessment in 3D-Printed Biobased Acrylates.

Suberin, a common biomass processing waste, is a complex biopolymer and a promising source for the biorefinery of chemicals. Six different approaches for the extraction of birch outer bark suberin fatty acids (SFAs) were explored, and their application in grafting the surface of cellulose nanocrystals (CNCs) was investigated. Successful CNC functionalization was controlled with FTIR and NMR analyses. In-depth research allowed us to evaluate the interface of the nanocellulose and polymer matrix. Three structurally distinct SFA-grafted CNCs were integrated into a vegetable oil-based acrylate resin in an ultralow concentration of 0.1 wt %. Five biobased acrylic resin formulations were prepared: without reinforcement, with CNC, and with three distinct SFA-grafted CNCs. Vat photopolymerization (VP) 3D printing was utilized for sample preparation. The effects of grafted CNC components on 3D-printed samples' thermal stability, thermomechanical properties, and wettability were evaluated in detail. CNC functionalization enhanced the interface with the polymer matrix, yielding up to a 2-fold increase in elongation and up to a 2.5-fold increase in strength in tensile and flexural tests compared to the polymeric matrix. The CNC-SFA-modified filler demonstrated performance comparable to, or even better than, petroleum-based chemical modification routes found in the existing literature. This study highlights a promising approach for green functionalization of CNCs and verifies its use in interface enhancement using a biobased acrylate matrix.

First report of Gnomoniopsis castaneae associated with branch dieback on chestnut tree (Castanea sativa) in Southern Chile.

European chestnut (Castanea sativa Mill.) currently reaches 1,470 ha, distributed from the Maule region to the Los Rios region in Chile. Almost 3000 tons of fruit have been exported in the last three years. A survey was carried out in January 2023 in an eight-year-old orchard located in Vilcún (38°34'46.22"S 72° 9'58.61"O), Araucanía Region. Chestnut trees with branch die back and reduced growth and vigor were detected. The incidence in the orchard was 3% (6 out of 200 trees) estimated by visual observation. Cross and longitudinal sections of the woody trunk of two trees were collected and examined, and an internal dark-brown discoloration to partial necrosis lesion was observed. To identify the causal agent, small pieces of wood from the edge of the symptomatic area were surface sterilized with 70% ethanol, rinsed twice with sterile distilled water, blotted on dry sterile filter paper, plated on potato dextrose agar (PDA) and incubated at 22°C. Fungal colonies were consistently isolated, and after 5 days, pure cultures were obtained by transferring mycelium to new PDA plates, preliminarily identified as Gnomoniopsis sp. (Visentin et al. 2012, Shuttleworth 2012). All cultures exhibited characteristics consistent with the description of G. castaneae (Syn. G. smithogilvyi), such as concentric development of greyish-brown mycelium, abundant stroma, hyaline conidia of 7.2 ±0.54 (6.1-8.1) X 2.3 ±0.26 (1.5-2.9) µm (n= 30), mainly biguttulate and fusoid. Total DNA was extracted, rDNA amplified using ITS1/ITS4 primers (White et al. 1990), and the fragment was Sanger sequenced and the sequence was deposited in GenBank (OR665735). BLAST analysis revealed a 99% identity to G. castaneae (MH384925). In addition, the DNA of the isolate was evaluated in a species-specific multiplex PCR (Silva-Campos et al. 2022), and the amplicons were electrophoretically separated, giving a similar band profile to G. smithogilvyi RGM 2903 and RGM 2904 strain from Chilean Collection of Microbial Genetic Resources. Pathogenicity of G. castaneae isolate (CV-11) was tested on ten replicates of 3-year-old C. sativa plants. Two wounds were made on the same season growing shoot and two on the previous season shoot. Longitudinal wounds (5 mm long, 4 mm wide and 2 mm depth) were made using a scalpel without removing the outer bark to inoculate the plants. Each wound was inoculated with a 5-mm mycelium plug, covered with the outer bark, and wrapped with Parafilm. Plugs of PDA were placed onto the wounds of two plants as control. The plants were kept in a growth chamber (22 ±1 0C and 90± 5% RH). All plants showed dark brown cankers measuring 20 to 40 mm long two weeks after inoculation. Also, most plants inoculated in the same season shoot presented wilted and chlorotic foliage. Mature conidiomata with cirri developed in most of the cankers. No symptoms were observed in the control. Fungal colonies of G. castaneae were reisolated on PDA from all inoculated chestnut plants and were not recovered from the controls. Recently, G. smithogilvyi has been identified as the causal agent of brown rot on chestnut nuts in Chile (Cisterna Oyarce et al. 2022); however, in several countries, it has also been associated as the causal agent of cankers in branch and stem of chestnut, as well as an endophyte in different hardwood species. Future studies on the incidence of this pathogen and its impact on chestnut yield should be carried out in the producing regions because it represents an emerging threat to Chilean chestnut production.

Identification of proper species that can be used to monitor and decrease airborne Sb pollution.

Heavy metal concentrations, which have increased continuously in the environment this century due to anthropogenic factors, severely threaten human and environmental health. Antimony (Sb) is one of the most toxic and harmful heavy metals in terms of human and environmental health. Therefore, the priority research subjects are monitoring the alteration of Sb pollution in the airborne and reducing pollution. This study was conducted to conclude the proper species to monitor and drop airborne Sb contamination on trees grown in Düzce, the 5th most polluted European city. This study examined samples taken from Pseudotsuga menziesii, Cupressus arizonica, Pinus pinaster, Picea orientalis, and Cedrus atlantica, and the Sb concentration changes based on tree species, route, tissue, and age range in the last 40years were evaluated. The study hypothesizes that Sb concentration varies depending on (1) tree species, (2) direction, (3) plant tissue, and (4) age range, all confirmed in this study. In conclusion, the maximum concentrations were achieved in the outer bark and east (5.45µgg-1) and north directions (6.72µgg-1), with high traffic density. In addition, the mining and industrial places (sources of metal pollution) are not close to the study area. Therefore, it was concluded that traffic pollution was the primary source of Sb pollution in the study area. The study revealed that C. arizonica is the most suitable species for monitoring and reducing the change in Sb pollution because the highest Sb concentration (4.47µgg-1) in wood (the largest organ) was obtained in C. arizonica.

Life cycle assessment of suberin and betulin production from birch bark

In this study, the environmental impact of suberin and betulin production from birch outer bark was evaluated using life-cycle assessment (LCA), and the ReCiPe 2016 Midpoint (H) method. The system boundary includes production of outer bark to betulin and suberin production, with bark residues utilized for energy production, including all inputs (materials and energy) and outputs. Three scenarios were used to examine using the allocation, extraction and hydrolysation of birch bark. In the baseline scenario (S1), the bark came from a biorefinery and processed in a separate unit, where the hydrolysed bark residue was incinerated to generate the heat; the integrated scenario (S2) and internal loop scenario (S3) considered production within a biorefinery but with different energy sources. The primary data were collected from laboratory experiments, and secondary data were taken from the literature and the ecoinvent 3.9.1 database. FU was 2.06 kg of polymer production that includes 1 kg of suberin and 1.06 kg of betulin production from the same process. The results showed that the global warming potential (GWP) for S1 was 15.5 kg CO2 eq. per FU, 16.22 kg CO2 eq./FU in S2 and 3.96 kg CO2 eq./FU in S3. According to our results, increasing the recycling rate of ethanol (50%, 90% and 98%) in the process and using wood-based energy from the biorefinery instead of Finnish mixed electricity resulted in a significant reduction in the most important environmental impact categories except land use.

Infected nursery stock and poor silvicultural practices contribute to development of Ceratocystis manginecans wilt and canker disease in Eucalyptus pellita

In Indonesia and Malaysia, Eucalyptus pellita has replaced large areas of Acacia mangium plantations as the latter species is highly susceptible to C. manginecans. This strategy may not be effective in the long term as E. pellita is also susceptible to Ceratocystis wilt and canker disease though it has higher tolerance than A. mangium. Furthermore, the pathogen has the capacity to evolve and adapt to new hosts. To highlight the need for careful sanitation in nurseries and the potential impact of wounding during silvicultural operations, two experiments were conducted to (i) demonstrate the ability of cryptic Ceratocystis infections in nursery plants to develop into Ceratocystis wilt and canker disease after planting out and (ii) assess the risk of Ceratocystis infection and disease development from different wound types. In the nursery, three-month-old mini-cuttings of seven E. pellita clones were artificially wounded and inoculated with two isolates of Ceratocystis manginecans near the base of the stem. The disease incidence and lesion length were measured one month later, just prior to planting out. After four months of growth in the plantation, the trees were harvested and stems sliced longitudinally to measure the length of xylem discolouration. Six of 36 ramets of susceptible clones died and the length of xylem discolouration was significantly greater in susceptible clones than in tolerant clones. The second experiment was based on inoculation of 12-month-old plantation-grown trees of one clone of E. pellita with one isolate of C. manginecans using six different wounding methods. The inoculated wounds on the trees all produced xylem discolouration, except for those that only penetrated the outer bark. Disease incidence was greater at stem heights of 30 to 90 cm than on the basal stem or branch stub. The experiment emphasised the importance of minimising the risk of C. manginecans infection following wounding in the nursery and in the field as the discolouration is an indication of xylem blockage that can lead to tree mortality.

Changes in anatomical characteristics of Falcataria moluccana wood due to Uromycladium tepperianum infection

Serious problems have occurred on Falcataria moluccana plantations because of gall rust disease caused by Uromycladium tepperianum. The disease inhibits tree growth, reduces wood quality, and can cause tree mortality. The presence of galls is a notable symptom of this disease. The study aimed to investigate the anatomy of the galls and the changes in wood anatomical characteristics of F. moluccana due to the infection of U. tepperianum. Wood blocks containing outer bark, cambium and xylem with different levels of severity of gall rust attack were removed from the main stem of F. moluccana trees. Microscopic observations were conducted to observe the anatomical characteristics of the galls, affected wood and healthy wood. The results showed that the anatomy of galls was different from that of affected wood or healthy wood. The percentage of vessel area, diameter of vessel, percentage of ray parenchyma and the length of wood fibres were significantly different between normal wood and affected wood. The results could be useful in understanding gall formation and assessing its impact on wood quality.

Quantitative and deep learning based fourier transform infrared radiation and tensile characteristics study on chemically treated hibiscus rosa-sinensis plant fibers

Incorporation of natural fibers with Fiber Reinforced Polymers (FRPs) is a promising avenue for sustainable and high-performance composite materials. The fibers, derived from outer bark portion of plants, offer significant merits such as renewability, low cost, and eco-friendly. Unique mechanical and physical properties, and widespread availability of Hibiscus Rosa-sinensis have made them subject of intense research interest. The present study investigated the chemically treatment of HRS Fibers using Sodium Hydroxide (NaOH), Potassium Permanganate (KMnO4), and Acetic Acid (CH3COOH) bat varying weight percentages (3, 4, 5 Wt%) and solutionizing times (1, 2, 3 h) based on Taguchi’s L27 orthogonal array. Fourier Transform Infrared (FT-IR) analysis revealed significant changes in O–H, C–H stretching, C=O moiety, aromatic ring, and C–O/C–C stretching. Potassium Permanganate treatment at 4 Wt% and 3 h of solutionizing time has yielded the best results. Multi-Layer Perceptron Artificial Neural Network (MLP-ANN) has been successfully applied to accurately predict the output physical characteristics of chemically treated HRS fibers using experimental data. Further Single Fiber Pull-out test results in Potassium Permanganate at 4 Wt% and 3 h solutionizing time as best sample with highest Tensile Strength and Modulus. This research underscores the effectiveness of the chemical treatment process in enhancing the properties of HRS plant fibers for potential composite applications.

Rhytidome- and cork-type barks of holm oak, cork oak and their hybrids highlight processes leading to cork formation

BackgroundThe periderm is basic for land plants due to its protective role during radial growth, which is achieved by the polymers deposited in the cell walls. In most trees, like holm oak, the first periderm is frequently replaced by subsequent internal periderms yielding a heterogeneous outer bark made of a mixture of periderms and phloem tissues, known as rhytidome. Exceptionally, cork oak forms a persistent or long-lived periderm which results in a homogeneous outer bark of thick phellem cell layers known as cork. Cork oak and holm oak distribution ranges overlap to a great extent, and they often share stands, where they can hybridize and produce offspring showing a rhytidome-type bark.ResultsHere we use the outer bark of cork oak, holm oak, and their natural hybrids to analyse the chemical composition, the anatomy and the transcriptome, and further understand the mechanisms underlying periderm development. We also include a unique natural hybrid individual corresponding to a backcross with cork oak that, interestingly, shows a cork-type bark. The inclusion of hybrid samples showing rhytidome-type and cork-type barks is valuable to approach cork and rhytidome development, allowing an accurate identification of candidate genes and processes. The present study underscores that abiotic stress and cell death are enhanced in rhytidome-type barks whereas lipid metabolism and cell cycle are enriched in cork-type barks. Development-related DEGs showing the highest expression, highlight cell division, cell expansion, and cell differentiation as key processes leading to cork or rhytidome-type barks.ConclusionTranscriptome results, in agreement with anatomical and chemical analyses, show that rhytidome and cork-type barks are active in periderm development, and suberin and lignin deposition. Development and cell wall-related DEGs suggest that cell division and expansion are upregulated in cork-type barks whereas cell differentiation is enhanced in rhytidome-type barks.

Coordination of bark and wood traits underlies forest‐to‐savanna evolutionary transitions

AbstractAimTo test the hypothesis that adaptive shifts leading to the assembly of tropical savannas involved coordination between bark and wood traits and to understand the underlying mechanisms.LocationTropical South America.TaxonAngiosperms (woody).MethodsWe compiled data on three bark traits (total, inner and outer relative bark thickness), wood density, maximum height, five secondary xylem traits and on species' habitat information (light environment, climate, soil and fire history) for Neotropical savanna, forest and generalist species (biome groups). We tested for pairwise and multivariate associations among traits across species and if biome group and habitat conditions explained species positions along the resulting strategy axes.ResultsTraits covaried along four different axes. The first axis was consistent with a trade‐off between fire (thick barks) and shade tolerance (low bark to diameter ratio, high vessel density) and contributed to differentiate the three biome groups according to the preference for shaded environments. Forest species also differed from savanna and generalist species in a separate axis by being more resource acquisitive. Maximum height and wood density did not strongly trade‐off with bark thickness, although maximum height was negatively covaried with relative outer bark thickness. Preference for shaded conditions was the main driver of variation in the two principal strategy axes, but temperature, fire and soil sand content also explained differences in plant stature between savanna and generalist species.Main ConclusionsAllocation to bark is constrained by trade‐offs with wood, opposing shade‐tolerant and acquisitive forest species to fire‐resistant and conservative savanna species. Rather than a single strategy axis, three axes are necessary to understand the functional differences among savanna, forest and generalist species. Because two of these axes are controlled by light availability, the associated traits tend to covary in space and time, but not across species.

Bark thickness and related parameters of tree species along an elevation transect leading to treeline in Central Himalaya.

Since treelines are generally fire-free, the trees growing there are expected to have thin bark, unless adaptation to other factors than fire results in the selection of a thick bark. Related to this is also higher proportional investment in inner bark in such an environment of infrequent fire. This study has considered stem bark thickness both in absolute and relative terms and also in the frame of the composition of outer and inner bark components of 20 tree species along an elevation transect (2100-3300m) in high ranges of the Central Himalaya leading to treelines. The study species varied from 2.1 to 16.2mm for total bark thickness and from 1.2 to 18.85% for relative bark thickness. The average absolute total bark thickness across the tree species decreased with elevation from forest to treeline, both when trees of all diameters (10.2 ± 0.84mm for forest and 6.9 ± 1.79mm for treeline) and those of the same stem diameter range (18-20m) were compared (9.10 ± 1.30mm for forest species and 6.38 ± 1.31mm for treeline species). Nevertheless, the treeline bark thickness was similar to those of several forest communities considered to have comparatively thick bark. Like many other biological structures, bark carries out multiple functions; therefore, its thickness could be affected by more than one environmental factor. We suggest that the requirement of mechanical resistance to the snowfall, rainstorms, wind and adaptation to a high sunlight and UV radiations or storage of water, and non-structural carbohydrates could affect total, outer and inner bark thickness. Studies on these aspects in similar ecosystems may help understand the multi-functional attributes of the bark. For trees of comparable sizes (trees with 18-20cm diameter at breast height) treeline species also had lower relative bark thickness (< 6%) than trees of forest below it (> 7%). The median proportion of inner bark of the total bark (70.5%) for our 20 species was more than that for savannas (~ 50%), exposed to frequent fire regime and similar to those of in cool sclerophyllous forests and temperate rain forests where fire return time is > 100years. However, it was lower than the inner bark proportion reported for tropical rain forests. To conclude, in spite of a fire-free environment, the Himalayan treeline and adjoining forest species show mixed bark characters.

Potential of Pinus eldarica Medw. tree bark for biomonitoring polycyclic aromatic hydrocarbons in ambient air

Urban trees' biomonitoring of pollutants such as polycyclic aromatic hydrocarbons (PAHs) yields pertinent and useful data for air pollution management. The aim of this study was to biomonitor PAHs in pine (Pinus eldarica Medw.) trees in the city of Isfahan and identify their sources. In total, 34 samples of outer bark of the trees were collected and their contents of 16 EPA PAHs were analyzed. With a median value of 136.3 ng/g, the total PAH contents in tree barks varied from 53.4 to 705.2 ng/g. The average values of the diagnostic ratios for Ant/(Ant + Phe), Flu/(Flu + Py), BaA/(BaA + Chr) and IP/(IP + BP) were 0.19, 0.49, 0.45 and 0.49, respectively, revealing the PAHs majority source of pyrogenic. Meanwhile, principal component analysis showed two major types of PAHs sources including pyrogenic (fossil fuel combustion and industrial activities) and petrogenic (uncombusted) sources. The average ratio An/(An + Phe) and Flu/(Flu + Py) in bark samples was close to their relevant ratios in ambient air which demonstrated the potential use of this approach for biomonitoring of PAHs.

Variation and Driving Mechanisms of Bark Thickness in Larix gmelinii under Surface Fire Regimes

Bark is vital for woody plants, providing protection, transporting nutrients and water, and storing essential resources. For fire-prone ecosystems, bark thickness is a key adaptive trait conferring fire resistance. Few studies have been conducted on the drivers of variation in bark thickness of the widely distributed Larix gmelinii (Rupr.) Kuzen in the Great Xing’an Mountains region, on the southern edge of East Siberia, where surface fire disturbances are frequent. To elucidate the relationships between variation in bark thickness (inner vs. outer bark) of L. gmelinii and plant size, environmental factors, and co-variation with other fire-tolerance traits, we selected 26 sites to set up plots and carried out a survey and bark sampling. Results showed that stem diameter primarily determines variation in bark thickness, especially outer bark. The proportion of outer bark to total bark increased accordingly as the tree increased in size. We also observed stronger correlated variation in outer bark thickness, tree height, and self-pruning capacity, implying that larger trees have thicker protective outer bark and taller heights with greater self-pruning, mitigating crown fire risks. Environmental factors appear to have a relatively limited effect on changes in bark thickness in L. gmelinii. Mean air temperature, annual precipitation, and total soil nitrogen content had some effect on outer bark thickness, and mean air temperature had some effect on inner bark thickness.

Innovative Approach to Enhance Bioavailability of Birch Bark Extracts: Novel Method of Oleogel Development Contrasted with Other Dispersed Systems.

Birch outer bark extract (BBE), containing pentacyclic triterpenes such as betulin, lupeol, and betulinic acid, is a widely recognized natural product renowned for its diverse pharmacological effects. However, its limited water solubility restricts its bioavailability. Therefore, the main objective is to enhance the bioavailability of BBE for pharmaceutical use. In this study, we aimed to develop a dispersion system utilizing a unique oleogel-producing method through the recrystallization of BBE from an ethanol solution in the oil phase. We generated an oleogel that demonstrates a notable 42-80-fold improvement in betulin and lupeol peroral bioavailability from BBE in Wistar rats, respectively. A physical paste-like BBE hydrogel developed with antisolvent precipitation showed a 16-56-fold increase in the bioavailability of betulin and lupeol from BBE in rat blood plasma, respectively. We also observed that the repeated administration of the BBE oleogel did not exhibit any toxicity at the tested dose (38.5 mg/kg betulin, 5.2 mg/kg lupeol, 1.5 mg/kg betulinic acid daily for 7 days). Betulin and betulinic acid were not detected in rat heart, liver, kidney, or brain tissues after the peroral administration of the oleogel daily for 7 days. Lupeol was found in rat heart, liver, and kidney tissues.

Polipropilen ve söğüt (Salix babylonica L.) odunu/kabuğu ile üretilen biyokompozitlerin özellikleri

The present study investigates the influence of various components of wood-plastic composites (WPCs) namely wood (W), inner bark (IB), outer bark (OB), and their varied percentage mixture on the mechanical behaviour. To achieve this goal, willow W, IB and OB flours were used as reinforcements at different weight percentages (17%, 27%, and 40%) in combination with polypropylene (PP) at varying weight percentages (44%, 58%, and 64%) along with a 2% compatibilizer. These constituents were processed in a twin-screw extruder with each treatment having a distinct mass proportion of reinforcement to polypropylene. Subsequently, test samples were fabricated using an injection molding machine from the obtained pellets. The mechanical properties of the resulting biocomposites were evaluated in accordance with ASTM standards. It was observed that, the flexural and tensile characteristics of the WPCs improved by the increasing inner bark content. Based on the findings of this investigation, a formulation comprising 27% wood, 27% inner bark, 44% polypropylene and 2% compatibilizing agent (W/IB/PP/MAPP) can be recommended where high mechanical properties are required. However, the other reinforced biocomposites exhibited notably lower notched impact strength compared to pure polypropylene.

Determination of the Changes in Airborne Ba and Mn Concentrations in Düzce City Center in the Last 40 Years with the Help of Cedrus atlantica Annual Rings

Heavy metals are pollutants that pose a great threat to humans, other living things, and the ecosystem. All barium (Ba) compounds, one of the most dangerous and harmful heavy metals, are poisonous. Manganese (Mn) is a harmful heavy metal that can cause hallucinations, fatigue, insomnia, weakness, forgetfulness, nerve damage, Parkinson's, and lung embolism. Therefore, observing the changes in Ba and Mn concentrations in the air is essential.&#x0D; This study aimed to determine the change of Ba and Mn heavy metals in the Cedrus atlantica tree based on direction, period, and organ. As a result, the annual rings of Cedrus atlantica show that the transfer of both heavy metals into the wood of Cedrus atlantica was limited. Therefore, the species is a suitable biomonitor that can be used to monitor the changes in Ba and Mn concentrations in the air. In addition, the study results revealed that the concentrations of both elements in the outer barks are quite high, and Ba pollution is primarily caused by traffic.

Variation of Ba concentration in some plants grown in industrial zone in Türkiye

This study was carried out on Fagus orientalis Lipsky (Oriental beech), Carpinus orientalis (Oriental hornbeam), and Quercus petraea (Matt.) Liebl. (Sessile oak) species that naturally spread out in the Çaycuma district of Zonguldak province, an industrial area in the northwestern Türkiye. The study aimed to determine the annual changes in barium (Ba) concentrations in the annual rings of the wood of the species. Moreover, Ba concentrations in the inner and outer bark were compared with the concentration in the wood, and changes in Ba concentration were determined by years and directions. As a result, the lowest mean Ba concentrations were found in hornbeam for all organs, whereas the highest values in the inner bark (944134 ppb) and wood (46996 ppb) were found in beech. The highest values in the outer bark were found in oak with 927482 ppb. For the three species, the values obtained on the outer side of the outer bark were higher. The study showed that all three species are useful in monitoring the changes in concentrations and the pollution of Ba in the air and can be used for this purpose. However, the most suitable species that can be used to reduce Ba concentration is Fagus orientalis, which has the highest Ba storage ability in the wood part.

Physical, mechanical, and anatomical properties of 12 jabon (Neolamarckia cadamba) provenances wood in Indonesia

Abstract. Anna N, Siregar IZ, Supriyanto, Sudrajat DJ, Karlinasari L. 2023. Physical, mechanical, and anatomical properties of 12 jabon (Neolamarckia cadamba) provenances wood in Indonesia. Biodiversitas 24: 5895-5904. Jabon is a raw wood material for paper industries and has a fast-growing ability. Comprehensive information on the fundamental qualities of wood from the 12 provenances of jabon (Neolamarckia cadamba (Roxb.) Bosser) is a critical aspect of understanding their superior properties. The age of the samples at the trial was 42 months old, and the number of trees tested was 12, representing one provenance. Wood samples for physical (disk samples), mechanical, and anatomical properties were sampled at a height and length of 1.3 m and 35 cm. The logs were divided into 5 cm and 30 cm for wood samples with anatomical and mechanical properties. The physical and mechanical properties were tested according to ASTM D 4442, ASTM D 2395, and ASTM D 143 standards. The physical (density, specific gravity, and moisture content), mechanical properties (MOE and MOR), and anatomical properties (fiber length and microfibril angle) were carried out on wood from 12 provenances. Physical and anatomical properties were tested, from the pith to the outer bark. The average green wood density was 0.94 gcm-3, while the highest was obtained in the Rimbo Panti, Nusakambangan, Kapuas Tengah, and Batu Hijau provenances. The average specific gravity value from the 12 provenances of jabon was 0.46 in Batu Licin and Batu Hijau provenances; the average moisture content on oven-dry weight was 105.13%; and the highest value was in the Kuala Kencana provenance. The average MOE and MOR values were 51,039.93 kgcm-² and 488.37 kgcm-², with a dry air moisture content of 13.62%. The highest MOE and MOR values were in the Batu Licin and Gowa provenance, with MFA testing varied at 11.54°. The fiber length from the pith to the outer bark tended to increase, with an average of 1183.28 ?m. Based on the value of physical, mechanical, and anatomical properties, 12 provenances of jabon can only be used as non-structural raw materials. The Batu Hijau provenances have the highest density and specific gravity. However, the highest fiber length was found in Gowa provenance.