Wood Stack Research Articles

Woodlog Inventory Optimization using Object Detection and Object Tracking

In the timber industry, keeping track of wood stacks is crucial to avoid stockpiles that are too large or too small ensuring efficient operations. Traditional methods are often time-consuming and inaccurate, leading to inefficiencies. This research proposes a novel solution for timber yard inventory management using cutting-edge technology.The approach utilizes YOLOv8, a powerful object detection algorithm, to identify wood logs in live video feeds. DeepSORT, a tracking algorithm, then follows these identified logs over time. This automation eliminates the need for manual tracking, minimizes errors, and enforces the "First-In-First-Out" (FIFO) principle for efficient inventory use.The study also compares DeepSORT to other tracking algorithms like OC-SORT and ByteTrack to identify the most effective option for this specific application. The results demonstrate that the proposed method significantly improves detection accuracy and reliability, leading to better inventory management.In essence, this research highlights how integrating advanced detection and tracking technologies can revolutionize timber yard operations. By automating processes and ensuring accurate inventory control, these technologies can significantly reduce costs and boost overall efficiency in the timber sector.

Experimental study on fire extinguishing performance of typical large space fires on ships

ABSTRACT A reliable fire extinguishing system is an effective measure to reduce the risk of ship fire. Based on a typical large space cabin platform, the experiments on the fire extinguishing performance of different fire extinguishing systems (high-expansion foam, aqueous film-forming foam and water spray) against oil pool fire (6 MW) and wood stack fire (0.3 MW) were carried out. The results show that for oil pool fire, the fire extinguishing performance of aqueous film-forming foam system is higher than that of high-expansion foam system. The fire extinguishing performance of high-expansion foam system is significantly affected by the relative location of high-expansion foam generator, fire source and obstacle. For wood stack fire, the fire extinguishing performance of water spray system is the best, and the fire extinguishing time is only 25 s, followed by the aqueous film-forming foam system (54 s) and the high expansion foam system (66 s).

Eco-friendly three-phase-gel foam with novel particle-gel crosslinking enhancing stabilization and fire extinguishing

To address the instability and limited fire-suppression effectiveness of foam agents, a three-phase gel foam incorporating α-olefin sulfonate (AOS), alkylphenol ethoxylates (OP-10), modified bentonite, and cellulose gel was developed. The foam formula was optimized by using response surface method. Combined with Zeta potential and FTIR, the intrinsic interaction between materials was analyzed. The foam decay process, liquid discharge regularity, and viscosity change under different additives were compared. The enhancement of its fire extinguishing ability was explored. Results show that: The optimized foam achieves optimal foaming volume and half-life. Surfactant adsorption reduces the surface charge of particles and stabilizes their dispersion in liquid membrane. Cellulose is wound between particles to form a stable absorbent skeleton and delay decay of foam. Foam adheres stably to solids and covers them with barrier, inhibiting wood burning. The time to extinguish wood stack fire was 84 s, a 36.84% improvement over Class A foam extinguishing agents.

Wood stack fire tests to evaluate the influence of extinguishing medium and driving pressure on fire extinguishing efficacy of forest trees

In order to explore efficient fire extinguishing agents for forest fires and further enhance fire prevention and extinguishing technology, an outdoor fire extinguishing test platform for burning wood stacks is constructed to simulate fire extinguishing scenarios in an open-air environment. Comparative analysis of fire extinguishing performance of hydrogel extinguishing agent and compressed air foam (CAF), and exploring cooling effect of fire extinguishing agent on internal high temperature of wood stacks under three driving pressures of 0.45 MPa, 0.55 MPa and 0.65 MPa. Test results show that both hydrogel extinguishing agent and CAF can effectively extinguish woodpile fires. Hydrogel fire extinguishing agents are more efficient in extinguishing fires by comparing extinguishing time and agent dosage. CAF in the early stages of firefighting, there is a momentary enhancement of flame, which leads to an increase in temperature of wood stacks and heat radiation fluxes. In contrast, hydrogel fire extinguishing agents can quickly reduce temperature and heat radiation flux of wood stacks, and cooling effect is significant; When driving pressure is increased from 0.45 MPa to 0.65 MPa, the flame extinguishing time gradually decreases. Analyzing cooling capacity in terms of consumption of extinguishing agent, hydrogel extinguishing agent increases about 40 %, while cooling capacity of CAF increases only about 22 %; Hydrogel's cooling efficiency is better than CAF, and increasing driving pressure helps to improve agent cooling efficiency. Among them, CAF needs to be within a specific gas driving pressure range, which can minimize negative effect of gas driving pressure and enhance its cooling efficiency.

Intelligent Control System for Wood Drying: Scalable Architecture, Predictive Analytics, and Future Enhancements

This article explores the research and development undertaken as part of a Master’s degree in Computer Engineering, with a primary focus on enhancing control mechanisms for natural wood drying. While this method is known for its cost-effectiveness in terms of labor and energy, it suffers from slower and unstable drying cycles. The project’s objective is to implement an intelligent control system that significantly improves monitoring and recording of humidity levels in each wooden stack. Additionally, the system incorporates the capability to predict humidity based on data sourced from a weather forecasting API. The proposed solution entails a three-layer system: data collection, relay, and analysis. In the data collection layer, low-computing devices, utilizing a Raspberry Pi, measure humidity levels in individual wood stacks. These devices then transmit the data via Low Power Bluetooth to the subsequent layer. The data relay layer incorporates an Android application designed to aggregate, normalize, and transmit collected data. Furthermore, it provides users with visualization tools for comprehensive data understanding. The data storage and analysis layer, developed with Django, serves as the back-end, offering management functionalities for stacks, sensors, overall data, and analysis capabilities. This layer can generate humidity forecasts based on real-time weather information. The implementation of this intelligent control system enables accurate insights into humidity levels, triggering alerts for any anomalies during the drying process. This reduces the necessity for constant on-site supervision, optimizes work efficiency, lowers costs, and eliminates repetitive tasks.

Equilibrium of a wood stack formed by close-packed cylindrical logs

Equilibrium of a wood stack formed by close-packed cylindrical logs

Fabrication of Ceramic-Polymer Piezo-Composites with Triply Periodic Minimal Interfaces via Digital Light Processing

The geometry of the phase interface in co-continuous piezoelectric composites is critical in improving their piezoelectric properties. However, conventional co-continuous piezoelectric composites are mostly simple structures such as wood stacks or honeycombs, which are prone to stress concentrations at the joints, thus reducing the fatigue service performance and force–electric conversion efficiency of piezoelectric composites. Such simple structures limit further improvements in the overall performance of co-continuous piezoelectric composites. In this study, based on the digital light processing 3D printing method, we investigated the influence of three different structures–the gyroid, diamond, and woodpile interfaces–on the piezoelectric and mechanical properties of co-continuous ceramic/polymer piezoelectric composites. These findings demonstrate that the gyroid and diamond interfaces outperformed the ceramic skeleton of the woodpile interface in terms of both mechanical and electrical properties. When the ceramic volume percentage was 50%, the piezo-composite of the gyroid surface exhibited the greatest hydrostatic figure of merit (HFOM), reaching 4.23×10−12 Pa−1, and its piezoelectric coefficient (d33) and relative dielectric constant (εr) reached 115 pC/N and 748, respectively. The research results lay the foundation for the application of co-continuous piezoelectric composites in underwater communication and detection.

Analysis of combustion characteristics of wood stack and absolute ethanol in fire extinguishing experiment

For the purpose of researching the rules of combustion heat release, ammonium phosphate dry powder extinguishing agent and water-based fire extinguishing agent were utilized before and after the class A fire common wood stack ignition fuel and class B fire anhydrous ethanol ignition fuel fire extinguishing. For wood stack fire, 0.5A wood stack was used for blank combustion test, and the pan fire ignition method for the same type and scale of wood stack fire extinguishing experiment. For absolute ethanol fire, fire suppression was studied using a 13B scale. The change characteristics of the combustion field before and after action of the dry powder extinguishing agent and water system extinguishing agent were measured by thermocouple, heat flow meter and digital camera. The findings of the experiment demonstrated that in the combustion experiment of wood stack, the temperature of 0.5A wood stack of the blank group could reach 800 °C, and the temperature reduction rate of free combustion was 2.62 °C/s. It took an average of 36.5s and 2.25 kg of ammonium phosphate dry powder to put out the fire，and the temperature reduction rate was 4.18 °C/s. The average amount of water-based extinguishing agent used to extinguish a fire was 1.21 kg, yet the average time to do so was just 12.5 s, and the average rate of temperature drop was 10.14 °C/s. In the experiment where an ethanol pool fire was being burned, the typical amount of water-based fire extinguishing chemical used was 3.44 kg, and the typical extinguishing time was 18 s, the maximum temperature drop rate could reach 35.6 °C/s in the initial stage of fire extinguishing, despite the fact that the dry powder fire extinguisher containing ammonium phosphate was used, the fire was not properly controlled.

Comparison of wood stack volume determination between manual, photo-optical, iPad-LiDAR and handheld-LiDAR based measurement methods

Comparison of wood stack volume determination between manual, photo-optical, iPad-LiDAR and handheld-LiDAR based measurement methods

Estimation of conversion factors for wood stacks in landings and their influencing parameters: a comprehensive literature review for America and Europe

In commercial transaction of stacked roundwood, the estimation of the stack net volume plays a key role. One generalized method to determine the net volume is using conversion factors that relate the gross and net volumes. In this literature review the developed methods to estimate the conversion factors as well as their influencing parameters were analyzed based on 153 references from America and Europe. According to the results, 48 different methods (including their variants) for estimating the conversion factors were developed. The newest methods enabled their accurate determination inexpensively, e.g., photo-optical methods or 3D simulation models. The analyzed references revealed that 30 parameters influence the conversion factors. Based on this comprehensive review, each stakeholder involved in the roundwood supply chain can know which method is used for estimating the conversion factors in the analyzed territories and which influencing parameters should be considered when purchasing roundwood in order to accurately assess the solid wood content in the stacks.

Design, optimization and implementation of a solar cell for wood phytosanitary treatment

ABSTRACT A research program was undertaken with the goal of developing dehumidifier solar wood dryers and wood thermal phytosanitary treatment cells. The first step of the program, was dedicated to the development of the numerical tools that would assist in the design and optimization of the dryers. These were based on an approach that combines micro (at the level of the wood board) and macro (at the level of the entire dryer and its solar heating system) modellings, and that uses typical year weather data, to perform the simulations. A finite difference numerical code was employed to predict the time evolution of the wood and air properties during the thermal phytosanitary treatment of wood. These predictions are employed as input to the TRNSYS© software to model the retained solar phytosanitary treatment installation configuration. In this system, the air leaving the treatment cell is recycled. But prior to injecting it back, it is mixed, in the right proportions, with outside air in order to adjust its humidity. The recycled air temperature is then risen to the operating value in an air-water heat exchanger fed from the storage tank of the solar water loop. The latter includes solar evacuated collectors, two pumps, a storage tank and a heat exchanger. The concept technical feasibility was prooved. The sytem optimization showed that, for a cell to be installed in Tunis, a 22 m2 evacuated tube collector and a 1.5 m3 water reservoir are needed for the treatment of 1 m3 wood stack i.e. 0.7 m3 of wood (reduced to 0.42 m3 in the winter season). A prototype of the optimized system was constructed and preliminary experimental tests are presented.

Development and evaluation of a novel 3D simulation software for modelling wood stacks.

Assessing the solid wood content is crucial when acquiring stacked roundwood. A frequently used method for this is to multiply determined conversion factors by the measured gross volume. However, the conversion factors are influenced by several log and stack parameters. Although these parameters have been identified and studied, their individual influence has not yet been analyzed using a broad statistical basis. This is due to the considerable financial resources that the data collection entails. To overcome this shortcoming, a 3D-simulation model was developed. It generates virtual wood stacks of randomized composition based on one individual data set of logs, which may be real or defined by the user. In this study, the development and evaluation of the simulation model are presented. The model was evaluated by conducting a sensitivity and a quantitative analysis of the simulation outcomes based on real measurements of 405 logs of Norway spruce and 20 stacks constituted with these. The results of the simulation outcomes revealed a small overestimation of the net volume of real stacks: by 1.2% for net volume over bark and by 3.2% for net volume under bark. Furthermore, according to the calculated mean bias error (MBE), the model underestimates the gross volume by 0.02%. In addition, the results of the sensitivity analysis confirmed the capability of the model to adequately consider variations in the input parameters and to provide reliable outcomes.

Comparison of fire extinguishing performance of four halon substitutes and Halon 1301

The Halon 1301 fixed gas fire extinguishing system used in ship engine rooms has been banned from production all over the world, because halon destroys the ozone layer. Therefore, it is necessary to find an environmentally friendly, compatible and efficient alternative firefighting system. In this study, we performed fire extinguishing tests in an ISO9705 standard room for four alternative fire extinguishing agents, as well as Halon 1301. The fire extinguishing efficiency of each agent was determined based on its cooling effect, dilution effect of oxygen concentration, the extinguishing time of the oil pool fire and the re-ignition probability of the wood stack. The test results provide data support for the selection of alternatives of Halon 1301 from the aspect of fire extinguishing efficiency. Among these results, Novec 1230 had the best ability to put out the oil pool fire, and HFC-227ea suppressed the wood stack fire the best. The difference between the cooling ability of each fire extinguishing agent was small, and the inert gas (IG-541) displayed the best ability to dilute oxygen. Hot aerosol required the longest time to extinguish fire. Consequently, under the existing design standards, HFC-227ea had the better firefighting efficiency, more suitable to replace Halon 1301.

Analysis of the Influence That Parameters Crookedness and Taper Have on Stack Volume by Using a 3D-Simulation Model of Wood Stacks

The influence that parameters crookedness and taper have on the stack volume was analyzed by using a 3D-simulation model in this study. To do so, log length, diameters at the midpoint and both ends, crookedness, bark thickness, taper and ovality were measured in 1000 logs of Scots pine. From this database, several data sets with different proportions of crooked and tapered logs in stack as well as with different degrees of taper and crookedness were created and taken as basis to simulate the stacks and carry out the analysis. The results show how the variation of these parameters influences the stack volume and provide their volume variation grades. These rates of variation were compared with measurement guidelines of some countries and previous research works. In conclusion, the parameters crookedness and taper influence the stack volume to a considerable extent. Specifically, the stack volume is increased as the crookedness degree or the proportion of crooked logs increases. In contrast, the stack volume is reduced as the taper degree or the proportion of tapered logs increases. Furthermore, the results demonstrate the capability of this simulation model to provide accurate results which can serve as a basis for future studies.

Insight to hydrophobic SiO2 encapsulated SiO2 gel: Preparation and application in fire extinguishing

Micron-sized hydrophobic SiO2 encapsulated SiO2 gel (HSESG) was prepared successfully by using SiO2 gel as the solid core and hydrophobic nano-SiO2 particle as the shell under high-speed shear stirring. The flowability, stability, particle size distribution, bulk density and water repellency of the powder were measured separately, and it was concluded that this type of product can exhibit smaller static angle, larger flow rate and lower bulk density. After the formation of a stable spatial network of SiO2 gel in its interior, relevant fire extinguishing experiments were carried out and HSESG exhibits higher efficiency in suppressing wood stack fires than that of ordinary dry water (DW) and ABC dry powder. As a high-efficiency fire-extinguishing material, it also exhibits excellent environmental friendliness and non-toxicity, which will make it have the potential to develop a new application market.

Residual mining caving face over the roadway and the key technology of deformation

Multi layer multi angle face roadway of coal mining face of residual mining brings technical challenges to the safety of the working face mining. With the background of the 6212 residual coal mining face in a mine in Shanxi, the deformation laws of the surrounding rock in the slanted roadway, the bottom coal slanting roadway and the intersection point are analyzed by numerical simulation. The simulation results show that at least the reinforcement measures should be carried out by 20m in the empty lane, and the plastic zone in the floor of the roadway along the top is obviously developed, and the stress concentration of the surrounding rock is high, and the support and management should be strengthened. In view of the space position of the site, the key technical measures are put forward, such as dense support or wood stack, anchor net cable, and super high water material grouting pre-filling, so as to ensure the safe recovery of the residual mining face.

Development of blue stain in mechanically harvested Scots pine (Pinus sylvestris) logs during storage

Blue stain is a type of discoloration that considerably lowers the aesthetic qualities of wood. During harvesting, fungal inoculum finds its way into the wood through places of cutting, delimbing, and damage to the tree stem. The development of peripheral blue stain in the logs of Scots pine (Pinus sylvestris L.) due to damage by a harvester head was investigated, using logs felled and delimbed with a chainsaw as reference. The development of blue stain was related to the age class of the stand, the date of felling, and the microclimatic conditions of the wood storage place. The mean surface area of blue stain in logs produced with the harvester was almost 35 cm2, approximately 30% larger than that of the reference logs. In stands of the fourth age class (diameter at breast height 32 cm), the surface of blue stain was more than two times larger than that of stands of the third age class (diameter at breast height 24 cm). The mean area of blue stain in wood stored after spring felling (19.3 cm2) was about 50% of that after summer felling (38.2 cm2). In particular, the development of blue stain in logs obtained with a harvester was visible between weeks 6 and 9 after spring felling and between weeks 3 and 6 after summer felling. For both felling dates, the range of blue stain depended less on air temperature around the wood stack and depended more on the duration of storage.

Mathematical modelling and numerical simulation of a simple solar dryer for tropical wood using a collector

The main objective of this paper is to develop a computational model and to simulate the drying of timber with a solar dryer. Two sets of equations have been established: one for the solar collector and the other for the drying chamber. The computed and measured outlet temperatures of the solar collector were compared. A very satisfactory prediction by the model is observed. The theoretical variations of the relative humidity and temperature of the air inside the drying chamber were computed and the analyses gave satisfactory physical meanings. The drying kinetic is a little faster. Using the solar collector, the final moisture content of the wood stack of iroko species (Chlorophora excelsa) is lower than the one obtained without utilization of the solar collector. The proposed modelling can be used to design and model other solar dryers.

Experimental Study on the Efficiency of Heptafluoropropane in Extinguishing Wood Stack and Oil Pool Fires

To study the efficiency of Heptafluoropropane (FM200) as fire extinguishing agent, several tests were done in ISO9705 room. It was observed that FM200 was effective on extinguishing both wood stack fire and oil pool fire, and all the fires were extinguished in 5 s. And FM200 could prevent the wood stack from burning again. Then, heat release rate and temperature in the fire room were depressed to a great extent by ejecting FM200. But it should be pay attention that the great pressure of the nozzle when FM200 be ejected in fire room may disturbed the flame and result in temperature rising for some bigger fires.

Validation of prediction models for estimating the moisture content of logging residues during storage

Increased use of forest biomass for energy and rising transportation costs are forcing biomass suppliers towards better moisture content management in the supply chain. Natural drying is used to decrease moisture content of energy wood. Drying is dependent on wood characteristics and weather conditions. Weather-dependent drying models for estimating the optimal storage time based on average moisture changes in fuel wood stacks stored outdoors have been developed for different stem wood and logging residues. Models are an easy option for estimating the moisture content of energy wood piles compared to sampling and measuring the moisture of samples. In this study, stand and roadside storage models for logging residues were validated against data from field studies and forest companies. Over 200 reference piles for the stand model, 23 piles for the roadside model and 10 piles for the combined model were studied. Results of the validation are promising. The difference between measured and modelled moisture was on average only 0.35%. The presented models can be implemented anywhere in Finland, because the Finnish Meteorological Institute has a weather observation service offering weather history data for every location in Finland. For international use, parameters need to be estimated on a case by case basis, but it should be possible to implement the approach also elsewhere.