Timber-colonizing gram-negative bacteria as potential causative agents of respiratory diseases in woodworkers

Occurrence Gram-negative bacteria occur commonly in the inner tissues of stored coniferous and deciduous timber, showing a marked variation in numbers. The greatest maximal numbers are found in the sapwood of coniferous timber. The common constituents of the Gram-negative biota are potentially pathogenic species of Enterobacteriaceae family of the genera Rahnella, Pantoea, Enterobacter, and Klebsiella. The air of wood-processing facilities is polluted with the wood-borne Gram-negative bacteria and produced by them endotoxin, as demonstrated worldwide by numerous studies. Effects There are three potential pathways of the pathogenic impact of wood-borne Gram-negative bacteria on exposed woodworkers: allergic, immunotoxic, and infectious. Allergic impact has been underestimated for a long time with relation to Gram-negative bacteria. Hopefully, the recent demonstration of the first documented case of hypersensitivity pneumonitis (HP) in woodworkers caused by Pantoea agglomerans which developed in extremely large quantities in birch sapwood, would speed up finding of new wood-related cases of HP caused by Gram-negative bacteria. The second pathway is associated with endotoxin, exerting strong immunotoxic (excessively immunostimulative) action. It has been demonstrated that endotoxin is released into wood dust in the form of nano-sized microvesicles, by peeling off the outer membrane of bacteria. Endotoxin microvesicles are easily inhaled by humans together with dust because of small dimensions and aerodynamic shape. Afterwards, they cause a nonspecific activation of lung macrophages, which release numerous inflammatory mediators causing an inflammatory lung reaction, chest tightness, fever, gas exchange disorders, and bronchospasm, without radiographic changes. The resulting disease is known as “Organic Dust Toxic Syndrome” or “toxic pneumonitis.” The potential third pathway of pathogenic impact is infection. The suspected species is Klebsiella pneumoniae that may occur commonly in wood dust; however, until now this pathway has not been confirmed. Conclusion Summarizing, Gram-negative bacteria-inhabiting timber should be considered, besides filamentous fungi and actinobacteria, as important risk factors of occupational disease in woodworkers that could be either HP with allergenic background or toxic pneumonitis elicited by endotoxin.

The Impacts of Calamity Logging on the Sustainable Development of Spruce Fuel Biomass Prices and Spruce Pulp Prices in the Czech Republic

Currently, due to the calamity of unplanned harvesting, the amount of biomass from wood products has increased. Forests occupy 33.7% of the total area of the Czech Republic; therefore, wood and non-wood forest products are important renewables for the country. Wood biomass consists mainly of branches and bark that are not used in the wood or furniture industry. However, it can be used in bioenergy, including wood processing for fuel. As spruce production in the Czech Republic increased from the planned 15.5 million to almost 36.8 million trees in 2020, the price of wood biomass can be expected to be affected. This study aims to develop a predictive model for estimating the decline in the price of wood biomass for wood processors, such as firewood or sawdust producers, as well as for the paper industry. Wood biomass prices are falling with each additional million m3 of spruce wood harvested, as is the decline in wood pulp, which is intended for the paper and packaging industries. The proposed predictive model based on linear regressions should determine how the price of wood biomass will decrease with each additional million harvested spruce trees in the Czech Republic. This tool will be used for practical use in the forestry and wood industry. The linear regression model is suitable for practical forestry use due to its simplicity and high informative value. The aim of the research is to model the dependence of the prices of firewood in the form of wood briquettes and pellets for domestic and industrial processing, as well as the prices of wood pulp on the volume of unplanned logging. It is a guide for the practice of how to use excess spruce wood from unplanned mining in the field of alternative processing with a sustainable aspect for households or heat production for households. The intention is to carry out modelling in such a way that it does not include prices of higher quality wood assortments, which are intended for the woodworking industry.

Lateral forces determine dimensional accuracy of the narrow-kerf sawing of wood

The shrinking global forest area limits the supply of industrially usable raw resources. This, in combination with the ever-increasing consumption of timber due to population growth can lead to the lack of a positive balance between the annual volumetric growth and consumption of wood. An important innovation toward increasing environmental and economic sustainability of timber production is to reduce the volume of wood residues by minimizing the sawing kerf. It results in higher material yield but may impact the dimensional accuracy of derived products. Therefore, the cutting tool geometry as well as the sawing process as a whole must be carefully optimized to assure optimal use of resources. The goal of this study is to better understand the causes of machining errors that occur when sawing wood with saws of varying thickness of kerf, with a special focus on re-sawing thin lamellae performed on the gang saw. Numerical simulations were tested against experimental results, considering influence of diverse components of cutting forces, in addition to the initial and operating stiffness coefficients of the saw blade. It has been demonstrated that asymmetric loads from the cutting process for the scraper saw blade can cause sawing inaccuracies. The simulation methodology developed in this research can be straightforwardly extended towards determination of optimal geometry of other cutting tools, particularly with the reduced sawing kerf. This may lead to more sustainable use of natural resources as well as an increase in economic gain for the wood processing industries.

Environmental Performance of Wood Bioconcretes with Different Wood Shavings Treatments

The wood bio-concrete (WBC) production is a solution for the advancement of sustainable construction, since it has the potential to recycle waste in the form of shavings generated in wood processing and stock CO2, contributing for climate change reduction. However, the chemical incompatibility between plant biomass and cementitious matrix leads to the need for previous treatment of wood shavings to application in bio-concretes. In the present study, one heat treatment and two alkaline treatments with immersion in Ca (OH)2 solution were evaluated using Life Cycle Assessment (LCA) methodology. The environmental modeling was performed by SimaPro, using the Ecoinvent database, and primary data collected in the laboratory. The potential environmental impacts were related to the compressive strength of produced WBC (in MPa) as an ecoefficiency indicator. Considering the functional unit of mechanical performance, the alkaline treatment with two immersions was the one that generated less environmental impacts.

Reducing the Energy Consumption of Circular Saws in the Cutting Process of Plywood

Cutting, as the most widely used machining process, is applied in both primary and secondary wood processing. Optimum cutting conditions that result in the high quality of the machined surface and low energy consumption are crucial for wood processing. The effects of the feed speed, cutting speed and average chip thickness on the energy consumption and surface temperature of a circular saw blade during the cutting process of two types of plywood with a thickness of h = 14 mm is described in this paper. In experimental measurements, two circular saw blades with cutting tungsten carbide inserts for wood were used as tools. One circular saw blade was standard, and was not surface treated (CSB1), and second circular saw blade (CSB2) differed by the powder coating surface and the length of the cutting edge. In the experiment, the energy consumption and the surface temperature of the circular saw blade was measured in order to find the optimal cutting conditions for the most energy-efficient cutting process. The results show that the cutting power and the surface temperature of the circular saw blade increased when the feed speed increased. The investigated values of the surface-treated circular saw blade were lower compared to the values of the standard circular saw blade. When comparing the lightweight plywood with the classic plywood, experimentally obtained cutting power values of the circular saw were made 19% lower on average by using the circular saw blade CSB1. When using the CSB2 circular saw blade, these values of the cutting power of the circular saw were 22% lower on average. The surface temperature of the circular saw blade is the highest on the outer edge (tooth root area 31.7 °C) and decreases towards the center of the circular saw blade. There must be a reasonable compromise between machine productivity and energy consumption.

NILAI USAHA INDUSTRI PRIMER HASIL HUTAN KAYU PADA CV SINAR JAYA DI KECAMATAN CIGUDEG KABUPATEN BOGOR

Community forests are the source of raw materials for the Primary Wood Forest Products Industry at CV Sinar Jaya in Cigudeg District, Bogor Regency. Optimizing the use of these raw materials can affect the business value of the wood processing industry. The purpose of this study was to determine the yield value and to analyze the business value of sawmill activities at CV. Sinar Jaya. The research method was carried out by means of quantitative analysis methods of collecting production data by direct measurement and interviews as well as calculating the value of economic income obtained from sawmill activities and overall waste utilization, the size of wood raw materials includes 10 centimeters to 30 centimeters with a length of 2 ,8 meters to 3 meters. The results showed that the average yield value is 55%, productivity is 1.51 m3/hour round wood, sawn wood is 0.83 m3/hour production cost is Rp 1,181,600,000.0/year, Income value is Rp. 1,509,600,0000.00/year, net profit value is Rp. 328,000.00/year, the value of marketing costs is Rp. 0 the value of the benefit cost ratio is 1.28/year and the work performance value of logs is Rp. 12,712.89 sawn wood Rp. 22,867.14. To increase the yield, the skills of the sawing workforce must be improved to minimize damage toeach sortimen. In order for business value to increase, productivity must be intensified and the availability of raw materials must be sustainable.

Experimental study of the characteristics of the circular saw cutting unit linear electric drive

Широкое применение круглопильных станков в лесопильной и деревообрабатывающей промышленности обусловлено их высокой производительностью, простотой, надежностью конструкции, низкой энергоемкостью. Для повышения полезного выхода пилопродукции применяют тонкие пилы. Существенным недостатком, ограничивающим использование таких пил, является их недостаточная жесткость и устойчивость во время работы. Для повышения изгибной жесткости круглой пилы применяются щелевые, роликовые, аэростатические и электромагнитные направляющие. Большинство направляющих создают сопротивление вращению диска пилы. К недостаткам круглопильных станков следует отнести механические потери при передаче крутящего момента от двигателя диску пилы. Колебания диска круглой пилы во время работы являются еще одним недостатком тонких круглых пил, которые снижают качество обработки древесины, приводят к поломкам пил и повышенному уровню шума. Для увеличения надежности узла резания, стабилизации диска пилы во время работы, уменьшения колебаний пильного диска предложено использовать линейный асинхронный дугостаторный двигатель (ЛАДД), ротором в котором является сама круглая пила. Для проверки разработанной математической модели ЛАДД с круглой пилой в качестве ротора была создана экспериментальная установка. Целью работы явилась экспериментальная оценка математической модели и анализ рабочих и механических характеристик ЛАДД, характеристики холостого хода и короткого замыкания двигателя, зависимости мощности и cos ϕ от скольжения. Экспериментально установлено влияние электропроводности диска пилы на эффективность ЛАДД. Для увеличения тягового усилия предложено нанести на боковые поверхности диска пилы материал с высокой электропроводностью (медь). Проведенный эксперимент показал существенное увеличение тягового усилия для диска пилы с покрытием медью. Установленная экспериментально величина магнитной индукции в воздушном зазоре ЛАДД показала корректное совпадение с результатами расчетов по разработанной математической модели. The circular saws are widespread in sawmill and woodworking industry due to their high productivity, simplicity, design reliability, and low energy consumption. Thin saws are used to increase the effective yield of sawn timber. The insufficient rigidity and stability during operation of such saws limit their use. Slotted, roller, aerostatic and electromagnetic guides are applied to increase the bending stiffness of a circular saw. Most such guides create resistance to the rotation of the saw blade. Mechanical losses during the torque transmission from the motor to the saw blade is one of the circular saws disadvantages. Another disadvantage of thin circular saws is vibration of the circular saw blade during operation, which reduce the quality of wood processing, lead to the saw crashes and increased noise levels. It is proposed to use a linear induction arc-stator motor (LIASM), implementing the circular saw is the rotor, to increase the reliability of the cutting unit, stabilize the saw blade during operation, and reduce the oscillations of the saw blade. The experimental setup was created to analyze the developed mathematical model of a LIASM with a circular saw as a rotor. The aim of the work is the experimental evaluation of the mathematical model and the analysis of operating and mechanical LIASM characteristics, idling and short-circuit characteristics of the motor, the dependence of power and cos ϕ on slip. The influence of the saw blade electrical conductivity on the efficiency of the LIASM has been experimentally established. It was proposed to apply a material with high electrical conductivity (copper) on the side surfaces of the saw blade to increase the tractive effort of the drive. The carried-out experiment showed a significant increase in the tractive effort for a copper-coated saw blade. The experimentally established values of the magnetic induction in the air gap of the LIASM showed good coincidence with the calculated results from the developed mathematical model.

Plywood Production Development Strategy at CV Alaf Denida

CV Alaf Denida is a local wood-processing company located in Babat, Lamongan, East Java. CV Alaf Denida started their business in 2013 focused on fabrication in processing of sengon (albasia) into bare core as main material for blockboard production. The factory located in Desa Dradah Blumbang. Kecamatan Kedungpring, Kabupaten Lamongan. This research aims to make a design production development strategies at CV Alaf Denida by identifying internal and external factor of the company, analyzing alternative strategies of production development and recommending priority strategies which is used by CV Alaf Denida in developing the products. The research metode is a qualitative method with an intrinsic case study approach. The collecting data method used in this research done with observasion process, interview, and documentation. Analysis tools used for analyzing the data are IFE, EFE, SWOT, and QSPM matrix for showing the priority strategies. The validity test of this research using researcher triangulation, method, and resource data.

Fluorescent CQD-Doped Styrene Acrylic Emulsion Coating Film with Enhanced Optical Properties

Styrene acrylic emulsions (SAEs) have emerged as a promising material for water-based coatings. However, they are still limited by their own defects in practical applications, poor weatherability, and degradation of performance at lower or higher temperatures. Here, we introduce a facile approach to producing fluorescent carbon quantum dots (CQDs) from wood processing residues and fabricating fluorescent CQD/SAE coating films via emulsion-casting. The addition of the fluorescent CQDs enhanced the optical performance of the CQD/SAE coating films. The fluorescent CQDs were prepared via a hydrothermal approach and were obtained after heating at 180 °C for 6 h at a reaction concentration of 50 mg/mL. The synthesized CQDs resulted in a high fluorescence, and the CQDs had an average size of 1.63 nm. Various concentrations of the fluorescent CQDs were doped into the SAE coating film, which improved its optical properties. We also characterized and discussed the products and then explored their optical properties. This study presents the potential of fluorescent CQD/SAE coating films for applications in anti-counterfeiting coatings, fluorescent adhesives, and papermaking.

The Analysis Of Marketing Mix Strategy Of Wood Processing In Increasing The Salling Margin

The purpose of this study is to analyze whether the application of the marketing mix strategy through the SWOT formulation can increase the sales volume of processed wood. This research was conducted at the office of PT. Three "Rs" located at Jalan Sultan Abdullah No. 75 Makassar, with the research time required by the author is approximately 3 (three) months starting from the beginning of May to July 2009. The population in this study are all consumers who use processed wood products, for housing development purposes in South Sulawesi, especially in the city of Makassar in the last year, so the population in this study is unknown. While the sample is as many as 300 respondents. Sampling was used using a non-probability sampling approach and the judgment method. Based on the results of the application of SWOT analysis, it appears that the strategy used by PT. The three "Rs" of Makassar in increasing processed wood sales are implementing the SO strategy, which is to make strengths to take advantage of opportunities, then the WO strategy by minimizing weaknesses to maintain opportunities, then the ST strategy using strengths to overcome threats and WT strategies that minimize weaknesses and avoid threats.