Different Levels Of Moisture Content Research Articles

Elastic behaviour of bamboo at nano- and microscale

This paper presents an anatomy-based numerical multiscale approach for modelling the mechanical behaviour of Moso bamboo, addressing limitations in previous research where the intricate microstructure was often simplified. The mechanical response of bamboo culms is predicted at the nano and microscale considering the orthotropic behaviour of cellulose microfibrils in different layers of tissues, deviating from conventional isotropic assumptions. Through nano and microscale finite element models, the impact of chemical composition and microfibril angle on elastic properties of different layers of the fibre and parenchyma cells are explored at two different levels of moisture content. At low moisture content, fibres within vascular bundles exhibit significantly higher longitudinal and transverse elastic moduli compared to parenchyma cells. When the moisture content is high, the properties of the fibre and parenchyma cells are less different. Anisotropic behaviour at the nanoscale contributes to a more accurate prediction of the mechanical properties of bamboo culms at the microscale, particularly in the transverse direction in moist conditions. This study lays the groundwork for forthcoming research in modelling the mechanical behaviour of bamboo culm at meso and macroscales.

Impact of moisture content of rice grain on infestation of angoumois grain moth, Sitotroga cerealella olivier

The influence of different levels of moisture content on survival of Sitotroga cerealella Olivier was studied in laboratory. It was observed that the initial moisture content of the grain played an important role in larval survival. The survival of the larvae increased significantly from 13.5 up to 17.8 per cent moisture content. It was observed that in pooled data of two years that the maximum larval survival was noticed in the rice grain moisture content having 17.8 per cent was 72.0 percent which was significantly superior over other grain moisture content. The grain with moisture content of 15.6 per cent recorded (57.0%) larval survival followed by the moisture content 13.5 per cent (43.5%). The lowest larval survival was observed in the grains having the grain moisture content of 7.2 per cent with 7.0 per cent survival. . KEYWORDS :Rice, grain,damage, Angoumois grain moth, Sitotroga cerealella Olivier, moisture content

Spectral characterization of fouled railroad ballast using hyperspectral imaging

The presence of fouling contamination in railroad ballast is a growing concern that causes deterioration, poor drainage functionality, and early failure of railroad components. Evaluation and characterization of fouled ballast are crucial for determining and monitoring fouling content (FC) and moisture content (MC) in ballast. However, human inspection, destructive testing, field sampling, and most available nondestructive evaluation methods (NDE) for inspection purposes pose safety risks, undermine the stability of the railroad substructure, or provide limited information about the condition of the ballast. This study presents the results of the spectral characterization of laboratory ballast samples using hyperspectral imaging (HSI) sensor. Nineteen (19) clean, dry-fouled, and wet-fouled samples were prepared and evaluated using HSI. The reflectance of ballast samples with different levels of MC and FC was determined in Visible-Near infrared (VNIR) and Near-infrared (NIR) wavelength range from 400 nm to 1700 nm. Results showed that; the presence of trapped water in ballast pores and free water in ballast voids reduced the reflectance; an increase in the dry fouling content increased the reflectance, and MC in wet-fouled ballast showed a nonlinear relationship with the reflectance or absorbance property. The presence of water was prominent in wavelengths of 1350 nm to 1550 nm. A second-order polynomial fit was adopted for the absorbance and reflectance features plotted against the MC, and the coefficient of determination (R2) values were determined. The R2 for the absorbance and reflectance plots between 900 nm and 1700 nm were 0.7747 and 0.8336 in the sample with 5% FC and 0.8790 and 0.9278 with 15% FC, respectively. For the 1350 nm to 1500 nm wavelength range, the R2 increased by 27% and 13%, respectively, for 5% FC and then 5% and 0%, respectively, for 15% FC. This study shows that absorbance features are more prominent than the reflectance features for determining MC in fouled ballast, with high prospects of detecting, monitoring, and quantifying MC and FC contamination using the HSI method.

Modelling hot distortion of inorganic bonded sand cores and application on complex 3D printed automotive cores

Inorganic bonded sand cores are getting increasing attention in industry due to their environmental advantages, and they are now widely used for series production in automotive applications. The advantages of these binder systems are nevertheless associated with a greater sensitivity of the core quality in relation to the manufacturing and storage process before casting, which is also having a major impact on the core strength. This paper presents the current work in integrating the modelling of the binder decomposition and evaporation of binder water with the mechanical performance of partially hardened and dried sand cores. This allows a local description of mechanical properties, considering different behaviour in compression and tension which depends on temperature and different levels of moisture content through the core. Recent work has shown the importance of including creep effects in the numerical modelling of 3D Printed (3DP) inorganic sand cores. Measurements of the mechanical behaviour of 3DP cores compared to shot cores have shown some fundamental differences in strength due to different density and binder content. This has been investigated in detail in collaboration with a major automotive manufacturer and the application of the model extension was done on a complex water jacket core.

Thermal Conductivity of Insulation Material: Effect of Moisture Content and Wet-Drying Cycle

The insulation materials are widely used in petrochemical, power engineering and other industries. The thermal insulation materials play an important role in the energy saving of district heating systems and in the building sector. In this work, the thermal conductivity of rock wool with different levels of moisture content and density of the insulation material was investigated by an experimental method. Experimental studies were carried out on rock wool from three different manufacturers. The effect of the wetting and drying cycle on thermal conductivity and density of the insulating material is analyzed. The thermal conductivity of the insulating material was measured using the guarded hot plate method. It was found that the thermal conductivity of insulating materials significantly affected the moisture content. The increase in thermal conductivity was from 1.33 to 4.42 times, depending on the density and the manufacturer of the rock wool. The wetting and drying cycles increase the thermal conductivity and density of the insulating material up to 2 and 2.5 times, respectively.

MODELLING FIELD WORKABLE DAYS ON FERRALSOLS IN CAMEROON

The absence of accurate field operation time records may result to wasteful use of the time available for farm operation which reduces the possibility of a successful operation. Making decisions related to whether or not the soil is suitable for farm activities is essential. However, about 70% of Cameroons soils are ferralsols and there is little to no data on how they respond to pressure from farm machinery intensities at different levels of moisture content. For the Bimodal Humid Forest Agroecological Zone of Cameroon, a model was developed to estimate soil suitability and the effective time available for farm operations on ferralsols. To achieve this goal, pot and field experiments were carried out to observed how bulk densities changes under different traffic intensities at various soil moisture levels. Also, NetBeans Integrated Development Environment (IDE) was used to develop a model in JAVA language that isran by a desktop. It was found thatferralsols have four main types of soil texture: Sandy Clay Loam, Clay, Sandy Clay, Clay Loam.Also, compaction caused by farm machinery traffic in these soils at depths of 0-15 cm tends to be greater than that at depths of 15-40 cm, which did not vary much moisture content at wilting point (MCWP) was found to be between 10% and 15%, and critical moisture content (CMC) ranged from 25.88% to 38.32%. Furthermore, ferralsols reach their optimum bulk density at moisture contents higher than field capacity. The NGUTRACT model developed permits to determine if a day was workable or not based on several variables and consequently permit to determine the number of days in a year. As a result, the model is site-specific, and depending on the soil type and moisture content, a day may be workable for one farmer while being non-workable for another in the same location.However, in order to provide a comprehensive picture of the entire agroecological zone, the results should be extended to the East and South regions. NGUTRACT should be used in conjunction.

Effects of moisture content on the quality of vermicompost produced from cattle manure

This research aimed to evaluate the quality of vermicompost produced from cattle manure at different levels of moisture content. For this purpose, cattle manure containing different moisture content such as 60% moisture (T1), 70% moisture (T2) and 80% moisture (T3) treatments were adopted with 3 replications. A total of 9 vermicomposting pits were filled with 25 kg of cattle manure, each having the same amount of red worms. Parameters studied were dry matter (DM), crude fibre (CF), crude protein (CP), ether extract (EE), ash and pH. Results showed that 63% DM was increased in T2 and this value was significantly higher than T1 and T3 (p> 0.05). The rate of CF degradation was 46, 78 and 72% in T1, T2 and T3, respectively. The CF degradation was also significantly higher in T2 compared to the other two treatments (p> 0.05). In the case of CP, a slightly higher CP was found in T2 followed by T1 and a little bit lower in T3 after 60 days of vermicomposting period. The EE content was slightly higher in all 3 treatments after 60 days of vermicomposting, but this difference was not significantly different among the treatments. The ash content was slightly higher in all 3 treatments after 60 days of vermicomposting, but this difference was also not significantly varied. The pH was significantly differed with the 3 treatments after 60 days of vermicomposting. From the above results, it was revealed that T2 would be the suitable level of moisture for CF degradation and increased CP content in the final vermicompost. Therefore, it might be concluded that cattle manure containing 70% initial moisture would be a good option for vermicomposting. Bangladesh Journal of Animal Science. 2022. 51 (2): 40-46

Machine learning algorithms to predict the dry matter loss of stored soybean grains (Glycine max L.)

AbstractPredictive modeling is useful to estimate future events based on collected data and discipline‐specific knowledge to guide decision making. Machine learning is one of the most frequently used methods to develop predictive models. There is limited literature in which machine learning techniques have been applied to soybeans' behavior during storage, and thus, the goal of this study was to test different model frameworks that estimate dry matter loss of soybeans utilizing data acquired from a dynamic grain respiration system with different levels of moisture content (12, 14, 18, and 22%, wet basis—w.b.) and temperature (25, 30, and 35°C). Five different models were trained and tested with a 2,625 point data set, which was partitioned into a training set (90%) and a testing set (10%). In the training step, 10‐fold cross‐validation was used to choose the best hyperparameters for each of the models. All fitted models were evaluated using standard metrics of Root Mean Square Error (RMSE), coefficient of determination (R2), dispersion of residual values, and a coefficient of performance. The Random Forest model performed best in terms of the distance between predicted and observed values, with three predicting variables. The use of predictive modeling in the recent Agriculture 4.0 scenario is a promising development for risk management and decision making in the context of grain and oilseed storage.Practical ApplicationsSoy is one of the most important crops in the world. The dry matter loss through respiration is a major problem during storage. The results of this study can aid researchers and the soybean industry in managing storage as a risk management and decision‐making tool.

The Concept of Optimal Compaction of the Charge in the Gravitation System Using the Grains Triangle for Cokemaking Process

Two isomorphic sets of grains, small and large, were analysed—without specifying their dimensions—under the acronym CMC (Curve of Maximum Compression) and taking into account the effects of segregation CMCS. The proposal is particularly valuable for optimal blend preparation in the gravity system in cokemaking. The main advantage of this work is the proposal of using the grains triangle, which limits the values calculated by the relations: bulk density-share of coarse/fine grains, for different levels of moisture content. Each system of changing shares of coarse grains is characterised by a constant C, but there is no need to determine it. Compliance of the calculated value with the experimentally determined value means that the given arbitrary grain set has reached its maximum density called the “locus”. The grains triangle practically covers the vast majority of laboratory and industrial test results, and geometrically or computationally indicates the ability of a given particle size distribution to reach maximum bulk density. This paper presents analysis of the results of tests on crushing, coal briquettes, and grinding coal blend in selected mechanical systems. Results of tests on coke quality (CRI, CSR) in connection with the grain size triangle are discussed.

Nitrogen release and re-adsorption dynamics on crop straw residue during straw decomposition in an Alfisol

Returning crop straw to the field not only improves the nitrogen (N) supplying capacity and N retention of soil but also decreases the amount of rural organic waste and prevents air pollution. Therefore, understanding the mechanisms of the N release and re-adsorption dynamics on crop straw residue during straw decomposition in agricultural soil is important, and this understanding can help us strengthen N fertilizer management during the crop growth period. An on-farm incubation experiment was conducted in the Jianghan Plain in Central China under flooded conditions using the nylon mesh bag method. Results showed that the decomposition rate of crop straw was much faster at the beginning of the incubation stage, whereas it was steady during the later stage with no observed differences among the three types of crop straw. After 120 d of incubation, the cumulative decomposition proportion of rice straw, wheat straw and rape straw was 72.9, 56.2, and 66.9%, respectively. The proportion of N that released from the three crop straws was 52.0, 54.4 and 54.9%, respectively. The zeta potentials and Brunauer, Emmett and Teller (BET) surface area of the rice, wheat and rape straw residues increased gradually as the decomposition period progressed. The water adsorption capacity of the rice straw was significantly affected during the decomposition period. The saturated water adsorption capacity of rice straw was the highest at 30 d of decomposition (4.17 g g–1) and then decreased slightly. The saturated water adsorption of wheat and rape straws reached the lowest value at 30 d and then gradually increased and became stable. All the results demonstrated that crop straw and straw residue can re-adsorb NH4+ ions from the surrounding solution. The re-adsorption was affected by the decomposition period and concentration of exogenous NH4+ and was independent of the crop species via the combined efforts of physical and chemical adsorption, ion exchange and water retention on residue surfaces. Future studies will focus on straw returning and N fertilizer application at different levels of moisture content of the soil reduce potential negative effects such as water-logging and excess N caused by the straw substrate.

In-Vessel Poultry Litter Composting to Facilitate Pathogen Reduction and Biofertilizer Production

Poultry litter-based organic fertilizers are usually incorporated into soil to improve its structure and fertility to increase crop production, however, poultry litter may also contain a variety of microorganisms which can compromise the safety of fresh produce when applied on agriculture lands. Composting can be a strategy to inactivate these microorganisms while creating a soil amendment beneficial for application to arable agricultural land. The objective of this study was to design and test the effect of moisture and temperature in a mechanically aerated in-vessel composting system for the purpose of reducing bacteria concentration in poultry litter while producing bio fertilizer. The actual composting occurred in four digesters which measured 1.2m x 1.2m x 1.2m. Four treatments were utilized with four different levels of moisture content in each vessel (treatment 1=65%, treatment 2=55% treatment 3=60% treatment 4=50%).Moisture gradually decreased and reached 55%, 44% and 48%, and 38.9% for treatment 1,2,3 and 4, respectively in the final compost product. The maximum average temperatures recorded for test 1, 2, 3 and, 4 were 50.54°C, 50.9 °C, 60.7 and 71.5°C respectively compared to outside temperature (15.4°C), and these temperatures were able to significantly reduce the concentration of total aerobic bacteria, fecal coliform and enterococcus listeria. The initial concentration of the compost piles was approximately 6.57, 6.04 and 3.72 log10 CFU/g of total aerobic bacteria, fecal coliform and enterococcus respectively. After analyzes, all target microorganisms were significantly eliminated. The significant levels of total aerobic bacteria, fecal coliform and enterococcus were p=0.0303, P=0.0258, p=0.0233 respectively. The presence of Salmonella spp. and Listeria spp. were not detected in all sampling period. Results of in-vessel compost analyses revealed a 16.9% N reduction; 10.1% P increase and 33.7% K increase. Moisture content decreased by 52.2% and elevated C/N ratio and pH by 27.7 % and 3.30% respectively. The leachates generated from the in-vessel composting for the first 21 days were analyzed, and the average results for week 1, 2, and 3, were observed to be 1043.7 mg/L, 1335.23mg/L, and 1029.9mg/L.Â

Effect of different conditions of storage on seed viability and seedling growth of six European wild fruit woody plants

Key messageMalus sylvestris(L.) Mill.,Pyrus communis(L.),Sorbus aucuparia(L.),Prunus avium(L.),Prunus padus(L.), andCornus sanguinea(L.) are related, co-occurring species producingorthodoxseeds. However, we observed differences in their response to storage conditions, such as storage at different seed moisture contents (5%, 8%, and 11%) and/or temperatures (− 3 °C, − 18 °C, and − 196 °C). Severe desiccation to ca. 5% of MC negatively affected seeds ofM. sylvestris. Seeds ofP. aviumwere sensitive to storage in LN or at − 18 °C.S. aucupariaseeds are best stored at − 3 °C, whereasC. sanguineaseeds tolerate desiccation and storage in LN. In general, species with deeper physiological dormancy (S. aucuparia,P. padus, andC. sanguinea) tended to be more tolerant to desiccation and low temperatures. For all species, storage conditions did not affect seedling growth.ContextWild fruit woody species face many threats such as genetic loss, population fragmentation, and alien species; thus, their genetic variability should be preserved.AimsTo examine the effect of storage conditions on seed viability and the initial growth of seedlings of six European wild fruit species: Malus sylvestris (L.) Mill., Pyrus communis (L.), Sorbus aucuparia (L.), Prunus avium (L.), Prunus padus (L.), and Cornus sanguinea (L.).MethodsSeeds were desiccated to three different levels of moisture content (ca. 5, 8, or 11%) and stored at three different temperatures (− 3°, − 18°, or − 196 °C; liquid nitrogen, LN) for up to 3 years. Germination and seedling emergence tests were performed as well as measurement of seedling growth.ResultsDesiccation of M. sylvestris seeds from 10.7 to 4.9% significantly lowered germination from 91 to 77% and seedling emergence from 88 to 74%. In P. avium, LN storage significantly inhibited seedling emergence, both in the laboratory and the greenhouse, but did not affect total seed germination. In P. communis, P. padus, and C. sanguinea, neither germination nor seedling emergence was affected by seed storage conditions. There were small or no differences in stem height and root collar diameter in the first year of seedling growth of stored seeds.ConclusionSpecies with deeper physiological dormancy (S. aucuparia, P. padus, C. sanguinea) tended to be more tolerant of various storage conditions. Seeds of P. padus and C. sanguinea can be stored long term at − 18 °C or in LN at 5–8% MC without losing viability. M. sylvestris and P. avium seeds are sensitive to desiccation below 6% MC or low temperature of storage at − 18 °C or − 196 °C, respectively. We observed that storage conditions had significant influence on germination and seedling emergence but had no effect on seedling growth after the first growing season.

Physicochemical Properties and Digestibility of Heat Moisture–Treated Potato Starches for Different Treatment Conditions

Potato starch was subjected to heat moisture treatment (HMT) in which the temperature and moisture content were varied. Two different levels of moisture content (30 and 35%) and temperature (100 and 120 °C) were selected. The crystallinity of the starches decreased after HMT, as confirmed by both X-ray diffraction (XRD) and Fourier Transform Infra-Red (FT-IR) analysis, and the XRD pattern of native starch changed from B-type to A+B type after HMT. Swelling, solubility, clarity and freeze-thaw stability of the HMT starches were less than native starch and were found to be dependent on both temperature and moisture content. Pasting viscosities of the modified starches were significantly lower than native starch and were found to be more for the starches treated at 120 °C than the starches at 100 °C. The pasting temperature increased after modification. The firmness of the modified starch pastes increased whereas the consistency decreased. The formation of resistant starch increased after HMT.

On the use of the combined FMC-ASED criterion for fracture prediction of notched specimens with nonlinear behavior

The Averaged Strain Energy Density (ASED) criterion has been widely used for the prediction of fracture conditions in a number of materials containing notch type defects, similarly to other well-known methodologies such as the Theory of Critical Distances (TCD). This criterion is linear-elastic, so the results obtained in linear-elastic materials have been accurate. However, as soon as the material behavior becomes nonlinear, the resulting accuracy decreases. With the aim of using linear-elastic simple methods (such as the ASED criterion) in nonlinear materials, several attempts have been made to convert a physically nonlinear behavior into an equivalent linear behavior. Thus, when the tensile behavior in plain specimens reveals nonlinearity, but the fracture behavior in the presence of defects is linear, the Equivalent Material Concept (EMC) has been successfully validated (EMC-ASED criterion). However, there are situations in which the nonlinear behavior takes place in both tensile and fracture behaviors, and the EMC-ASED criterion loses accuracy and requires further evolution. At this point, the Fictitious Material Concept allows the analysis of nonlinear materials (at both tensile and fracture conditions) to be performed with significant accuracy.In this context, this article provides the prediction of fracture loads in single edge notched bending (SENB) specimens made of short glass fiber reinforced polyamide 6 (SGFR-PA6, 10 wt.%) containing U-notches and different levels of moisture content. The predictions are obtained through the combination of the FMC and the ASED criterion (FMC-ASED combined criterion). The results are significantly more accurate than those obtained through the ASED and the EMC-ASED criteria, but less accurate than those used when combining the FMC with the TCD.

Design and Fabrication of Cassava Grating Machine

The Cassava grating machine that was designed has two modes of operation, it can be powered either electrically or manually. It takes care of power failure problems. The Cassava is fed with the Machine through the hopper made of metal sheet to the granting drum, which rotates at a constant speed. This process grates the cassava into cassava pulp. The chute made up of metal sheet accepts the pulp and sends it out because of its inclination which is operated manually. The efficiency of the machine was found to be 82.7%, which the efficiency of the electrically powered machine was found to be 79.5%. The need for the hygienic processing of cassava, is very important as well as the prevalent conditions in the commercial grating areas of this staple food as it is likely to be affected by food contamination. A home-scale cassava grating machine was designed and fabricated, with machine efficiency, safety factors, and portability all taken into consideration. The grating hopper and drum are modified with the drum having a stainless-steel sheet wrapped around a galvanized mild steel core. The machine runs on a single phase 6.5HP (horse power), electric motor, multiple customers with increased through-put when compared to other available grating machines. The performance efficiency of the grater for fresh cassava samples depends on the results showing significant variation for combination of process parameters. This study carried out the performance and optimization evaluation of single barrel cassava grating machine on selected fresh and stored cassava species. The species were used at different levels of moisture content, 70.4% db. and 58.4% db. depicting the average moisture contents obtained for fresh and stored cassava respectively.

Effect of Moisture Content on Aflatoxin B1 production in Wheat Flour Samples Collected from Lahore, Pakistan

The present research was conducted to study the effects of moisture contents on the level of aflatoxin B1 (AFB1) in wheat flour samples collected from different areas of Lahore. Total 30 samples were collected from different locations and shops in Lahore- Pakistan, making sure that they have different levels of moisture contents. Thin layer chromatography technique was (TLC) selected to check the AFB1 contamination levels in wheat flour samples. The AFB1 was detected in 10 samples (33.33%), out of which 7 samples (23.33%) had AFB1 levels within permissible range, i.e. 2 μg/kg, while 3 samples (10%) contained AFB1 levels i.e. 2.67 μg/kg, 2.93 μg/kg, 3.01 μg/kg above permissible range. From the study it was concluded that the contaminated samples had greater moisture contents than that of non contaminated samples. Sample with 35% moisture content has 3.01 μg/kg AFB1 levels. The food stuff can be protected from AFB1 production by minimizing the moisture contents, the lesser the moisture content, the lesser will be the aflatoxin levels in food samples.

Study of engineering properties of selected vegetable seeds

Quality seed is the foundation block of vegetable production system. Proper post-harvest processing of seed is important to maximize yield, longevity, vigour, and overall quality. The engineering properties determination is the first and foremost step for the design of any seed processing, storage and handling machine or equipment. Engineering properties like geometric, gravimetric, frictional and aerodynamic properties of bottle gourd, sponge gourd, garden pea, and radish seeds have been determined at different levels of moisture content (7.5 % to 19 % dry basis). Results revealed a quadratic increase in all properties with moisture content except for gravimetric properties. The properties like sphericity (0.83), bulk density (710.61 kg/m3), true density (1109.79 kg/m3), angle of repose (26.41°), terminal velocity (10.13 m/s) and drag coefficient (0.92) were highest for garden pea seeds. Whereas, bottle gourd seeds exhibited maximum values for size (7.17 mm), projected area (115.68 mm2), porosity (53.4%) and coefficient of friction (0.727).

Shelf life prediction of oxygen‐sensitive products: The influence of moisture on prediction accuracy for freeze‐dried coffee

Optimised packaging requires that properties are matched to the protection requirements of food for its shelf life duration. Benefits include reduced packaging costs, use volumes, and potentially improved environmental performance. The ability to predict product shelf life in different materials can assist in selecting optimal packaging. However, the availability of such tools is limited, and risk for over packing exists. The aim with this work is to develop a prediction approach which can be applied to assist users to select more optimal packaging materials. Soluble coffee was used to develop the approach, where oxygen consumption of the product is used as a quality indicator. The effect of moisture content on O2 consumption was studied to determine its influence on prediction accuracy. Samples were prepared with different levels of moisture content. O2 consumption rates were measured, and a notable influence of moisture was observed. A model was developed to predict the O2 consumption of the product when packed in a pouch. The model considers oxygen and moisture permeation properties of the packaging film, O2 and moisture differential between the interior and exterior of the packaging, and the evolution of the O2 consumption rate as a function of moisture increase. To test model accuracy, coffee samples were packed in flexible pouches, and O2 consumption was measured which showed that predicted and measured values shared the same trend characteristics. We show that considering both moisture and O2 ingress simultaneously leads to more precise shelf life prediction as oxidation rate is influenced by moisture content.

CUTTING TEST AS SOURCE OF FRACTURE TOUGHNESS AND SHEAR YIELD STRENGTH FOR AXIAL-PERPENDICULAR MODEL OF WOOD CUTTING

The objective of this study was to develop and design a model of calculation of fracture parameters for axial-perpendicular model of wood cutting. Two selected wood species of Central Europe provenance spruce ( Picea abies L.) and beech ( Fagus sylvatica L.) of two different levels of moisture content (w = 8% and 16%) were sawn. The measurements of energetic effects (cutting power and cutting force) while sawing wood were carried out on the laboratory stand which simulates conditions of circular saw blade cutting. Using the newly designed model, it is possible to determine fracture toughness and shear yield strength only on the basis of the cutting tests. Unknown parameters, which are then applied in the model, were set based on calculation of the forces acting on the workpiece and the tool. Using the measured cutting force and the feed force, other component of the resulting active force were calculated. The computation was based on Ernst-Merchant’s force decomposition diagram. Results confirmed the obvious influence of the anatomical structures and moisture content on the size of fracture parameters.

Prediction of modulus of elasticity of poplar wood using ultrasonic technique by applying empirical correction factors

In this research, dynamic modulus of elasticity (MOE) of poplar wood was predicted under two different levels of moisture content, two different specimen dimensions, and three different transducer directions by ultrasonic technique. The main goal of this research was evaluate five correlations for the prediction of MOE and finding the best model based on a correction factor. Ultrasonic velocity in the wood was measured using Sylvatest Duo 9906-015 device. Dynamic MOE was calculated using measured ultrasonic wave velocity and density in different transducer directions and compared to static MOE. Static MOE was directly measured using Instron-4486 universal testing machine. Results generally showed that only two correlations had acceptable errors in the range of 5.8%–10.4% for all levels of moisture content. The results also showed that the ultrasonic technique is a suitable and accurate method for the prediction of MOE of poplar wood using models 2 and 3 (with around 7% relative error), especially in lower level of MC. Transducer direction B give the best outcomes along with minimum relative error (6.7%) among the other transducer directions. The empirical correction factors have an impressive effect on the reduction of relative error.