Wood Plastic Research Articles

A hospital-based case-control study of acute myeloid leukemia in Shanghai: Analysis of environmental and occupational risk factors by subtypes of the WHO classification

The objectives were: (1) to investigate potential environmental and occupational risk factors of acute myeloid leukemia (AML), and (2) to explore the relationships between risk factors and AML subtypes according to the World Health Organization (WHO) classification. The investigation was a hospital-based case-control study consisting of 722 newly diagnosed AML cases (August 2003 through June 2007) and 1444 individually gender–age-matched patient controls at 29 hospitals in Shanghai. A 17-page questionnaire was used to obtain information on demographics, medical history, family history, lifestyle risk factors, employment history, residential history, and occupational and non-occupational exposures. Certain occupations of interest triggered a second questionnaire, which was occupation-specific and asked for more details about jobs, tasks, materials used and work environment. Exposure assessments were based on the questionnaires, on-site workplace investigations, data published in the Chinese literature, historical exposure measurements maintained by government health agencies, and expert opinions of a panel of local scientists who were familiar with workplaces in Shanghai. Risk estimates (odds ratios and 95% confidence intervals) of individual risk factors were calculated using conditional logistic regression models. A number of potential environmental and occupational risk factors were associated with an increased risk of AML (all subtypes combined) and/or individual subtypes; including home or workplace renovation, living on a farm, planting crops, raising livestock or animals, farm workers, metal workers, rubber and plastic workers, wood and furniture workers, printers, loading and unloading workers, automobile manufacturing, general construction, and food and beverage industry (restaurants and other eateries). Exposures associated with an increased risk of AML (all subtypes combined) and/or individual subtypes included benzene, diesel fuel, metals, insecticides, fertilizers, glues and adhesives, paints and other coatings, and inks and pigments. Multivariate models were used to adjust for potential confounding exposures, and several potential risk factors were subsequently eliminated. The results of the investigation indicated that some risk factors applied to all or most subtypes (e.g., living on a farm and overall AML and several subtypes), while others to specific subtypes only (e.g., raising livestock and AML with multilineage dysplasia). Thus, some risk factors were subtype-specific. The difference in risk by subtype underscores the importance of the etiologic commonality and heterogeneity of AML subtypes.

Comparison of benthic algal composition developed on different substrata in Lake Donghu, Wuhan

测定了富营养化武汉东湖中的底栖藻类在不同人工基质上建群发展为成熟群落的生物量(Chl.a),定性分析了人工和天然基质上成熟硅藻群落的种类组成和结构特征.通过比较建群期间底栖藻类在花岗岩、玻璃、塑料(PVC)和木板4种不同人工基质上的生物量变化,发现底栖藻类在PVC上的生物量峰值(Chl.a,71.0μg/cm²)明显高于其它人工基质,说明PVC是最适合底栖藻类生长的人工基质.分析发现人工基质花岗岩上底栖硅藻群落的种类组成、主要优势种类、群落的相似性指数、多样性指数都和天然基质上的硅藻群落是高度相似的,显示该人工基质能够代表天然基质上的藻类群落,表明花岗岩应该是以底栖藻类作指示生物监测和评价水质的理想人工基质.;Biomass (Chl.a) of benthic algae colonized and developed mature community on different artificial substrata was determined in eutrophic lake Donghu, and species composed and structure characteristic of mature diatom communities on artificial and natural substratum were analysed qualitatively. Biomass variance of benthic algae was compared on four different artificial substratum, granite stone, glass, plastic (PVC) and pine wood during the colonization period, and the peak biomass of benthic algae (Chl.a, 71.0μg/cm²) on PVC was significantly higher than that of the other artificial substrata, which showed PVC was the most suitable artificial substratum for benthic algae. Species composition, dominant species, similarity index and diversity index of benthic diatom communities showed a relatively high degree of consistency between natural and granite artificial samplers, which suggested granite should be the most favourable artificial substratum with benthic algae used as indicatory biology that monitored and evaluated water quality.

Trends in the US decking market: A national survey of deck and home builders

The deck-building industry is going through a period of rapid growth and dramatic change with respect to the types of materials available to build decks. Naturally durable timber species (i.e., redwood, western redcedar, Alaska yellow-cedar and tropical hardwoods) are facing acute competition from engineered decking products, primarily plastic lumber and composite wood products. The results of a 2004 national survey of 156 deck builders and 212 home builders indicate that wood–plastic composites are quickly gaining popularity among deck-building professionals as they increase their market share. This paper investigates deck-building professionals’ use and perceptions of the different decking materials. The study also reveals the usage patterns of the various decking materials in the primary end-use applications (substructure, deck surface and deck accessories). Finally, a comparative assessment of the different decking materials relative to a common set of material attributes is presented. Key words: decking market, deck-building practices, decking material, residential housing, deck builders, homebuilders

Biodegradation and appearance of plastic treated solid wood

The biodegradation of plastics and wood with different susceptibility to fungal attack have in this study been compared in order to show the biodegradability in relation to the properties of plastic and solid wood. Wood blocks of Scots pine and English Oak were treated with biodegradable aliphatic polyester, polycaprolactone, and a non-biodegradable aromatic thermoplastic, polystyrene. The plastics were applied to the wood samples dissolved in an organic solvent and thereafter the treated wood samples were exposed to brown rot decay ( Postia placenta) in an agar plate test for 8 weeks. The polycaprolactone treatments did not result in wood protection, whereas polystyrene treatments provided a protection from fungal attack. Both plastics are transparent and after treatment the solid wood blocks retained their natural wood appearance with a somewhat darker shinier surface. Scientific relevance Usually commercial wood-plastic composites are made using wood derived lignocellulose-fibers melt-blended in a screw extruder with a plastic matrix, and then the resulting material is mainly a plastic (in terms of properties and appearance) which contain some lignocellulose. We have instead used solid wood to which we have added transparent plastics, which preserve the unique and precious esthetic value of natural wood. This study describes the biodegradation of two (a more and a less resistant) wood species in combination with a biodegradable and a non-biodegradable plastic. The purpose was to study any synergetic effect in the biodegradation property between solid wood and plastic since there is a socio-environmental desire to use biodegradable plastics of renewable raw material for e.g. composite material. We show that both the wood and the plastic influence the biodegradation, for example by using an easily degraded European wood specie in combination with a biodegradable plastic (polycarolactone) no protection of the wood is obtained, whereas a relative small amount recalcitrant plastic (polystyrene) can somewhat protect both Scots pine and Oak wood without significantly compromising their appearance.

Green Composites: Development of Poly(Vinyl Alcohol)-Wood Dust Composites

As part of an ongoing research on biodegradable composites, which can be aptly termed as green composites, the present article reports on the incorporation of wood industry waste material, wood dust, as organic filler in film matrix based on Poly(Vinyl Alcohol) as continuous phase. In this study as filler, dust of Piyasal wood was used. In order to improve the compatibility between wood dust and plastic material, different amounts of cross-linking agents, such as glutaraldehyde, were used and the effect of these on water absorption and biodegradability was studied. The as-synthesized PVA-Wood dust composite materials are typically characterized by Fourier-Transformation Infrared (FTIR) spectroscopy and, wide-angle x-ray diffraction. The mechanical analysis of the composite material was studied by tensile test. The morphological image of as-synthesized materials was studied by optical microscope (OM).

Influence of drying temperature upon some mechanical properties of beech wood

The paper presents the results obtained in an experimental study concerning the influence of drying temperature upon the mechanical properties of beech wood (Fagus sylvatica L.). Sound wood samples without red heart were cut from white (unsteamed) beech timber parts, dried at different temperatures: 20 °C, 80 °C, 90 °C, 100 °C, 115 °C and same relative air humidity: 50%. After performing classical tests for evaluation of some selected mechanical properties, the following conclusions could be drawn: all bending properties (static bending strength, modulus of elasticity and impact bending strength) increased with increasing temperature, confirming thus the benefiting effect of heat upon wood plasticity. The tensile strengths, both parallel and perpendicular to grain, increased with increasing temperature, but only in the range below 100 °C; as soon as the temperature exceeded this value, the tensile strengths began decreasing. As far as compression strength parallel to grain, shearing strength and splitting resistance is concerned, no significant influence of temperature could be established. However, it seems that these properties are negatively affected by kiln-drying, as even with low kiln-drying temperatures these strengths are much lower than in case of air-drying.

Plants move up the reinforcement agenda

Until recently the term ‘reinforced plastics’ has usually meant glass, carbon, aramid or polyethylene fibres, incorporated in petroleum-based resins. Several factors are now stimulating interest in plant based fibres and bioplastics for composites manufacture. These factors include the drive for sustainable technology, legislation on the recycling of end-of-life vehicles and the automotive industry's continuing demands for weight reduction and control of material costs. Geoffrey Pritchard highlights some of the developments at a recent conference on Wood and Biofiber Plastic Composites.

Fabrication and Properties of Absolutely Recycled Plastic Wood Composites

In this study, the absolutely recycled plastic wood (ARCPW) was fabricated with post-consumer high density polyethylene (HDPE) and wood flour from the saw mills. The alkaline, silane and maleic anhydride modified polypropylene (MAPP) were used as modifiers to treat wood fiber and improve the interfacial adhesion of ARCPW. Effects of wood fiber length, weight fraction and surface treatment on the mechanical properties of ARCPW were investigated. The flexural fracture surfaces of ARCPW were examined and the fracture mechanism of ARCPW was also analyzed in this paper. The results indicated that ARCPW with wood fiber simultaneously treated by alkaline, silane and MAPP possesses the best mechanical properties. The higher the content of wood fiber, the better the flexural strength of ARPCW. The interfacial adhesion of prepared ARCPW is ideal and a good compatibility between wood fiber and matrix was obtained.

Symmetric sculpture

The extended face planes of symmetric polyhedra form a set of interconnected canvases that can be used as the framework for sculpture. Examples constructed from metal, wood, or acrylic plastic demonstrate the versatility of the approach. A special-purpose software tool is described which allows the artist to select families of such planes, to draw within them, to maintain constraints concerning points lying on their intersections, to view and modify the results interactively in real time, and to output the result for production either as 3D solid freeform fabrication or 2D laser-cutting or plasma cutting.

窯業系サイディングの耐凍害性に関する屋外暴露実験

The purpose of this paper is to clarify the frost resistance of fiber reinforced cement sidings through an outdoor exposure test, and the relation between the results of the outdoor exposure test and the results of the accelerated freezing and thawing test on frost resistance. The outdoor exposure test was carried out at Sapporo, Kamiiso and Kitami for 10 years, and the accelerated test was performed according to JIS A 5422-1995. 21 kinds of sidings which differ in production methods and raw materials were prepared. The results obtained may be summarized as follows: 1) Sidings having a apparent density above 1.2g/cm^3 are durable to freezing and thawing action in outdoor exposure test and accelerated test. Also sidings containing air-void, preformed cellular plastic spherical materials and wood flake are durable. 2)The results of the outdoor exposure test are not consistent with the results of the accelerated test. It is surmised that there are affectable factors on frost resistance which are not taken account in the accelerated test.

Navy Demonstration Project

The Navy Demonstration Project is a multi-layered collaborative research project between architects, material, and structural engineers the end product of which is a 5,400 square foot demonstration building for the U.S. Navy designed and built by architecture students at the Wood Materials Engineering Laboratory on the campus of Washington State University (Figures 1, 2). The project is a unique combination of design and science; it engages a series of experiments with new material development in the field of plastic wood composites, building envelope design and structural engineering. On the one hand, the project was an exploration into design possibilities inherent in engineered products such as wood-plastic composites, Oriented Strand Board (OSB), Laminated Veneer Lumber (LVL) and I-joists; on the other hand, the project was an exploration of the engineering potentials in these same materials. The building is possibly the first in the world to use wood-plastic composites so extensively and for such a wide variety of applications.

Multiscale study of fatigue behaviour of composite materials by χ-rays computed tomography

The study of microstructure and damage mechanism of elastomeric matrix (EMC), wooden plastic (WPC) and also metal matrix (MMC) composites involves a complicated interplay between material properties and service conditions. So, the study of texture deformation and fatigue behaviour of EMC, WPC and MMC specimens is of considerable practical interest. On the other hand, the occurrence of defect in specimens in working conditions is an important problem. It is necessary to improve the microstructure for delaying instability, in order to obtain a higher service capacity. This paper presents the in-situ observation of damage by using χ-rays computed tomography (CT) Medical Scanner installed in the ITMA research centre for evaluating the fatigue behaviour of EMC, WPC and MMC. A tomographic inner-health analysis will be given from 2D slices of the examined parts in laboratory scale on the WPC, EMC and MMC specimens used in automotive industry and aeronautical fields.

Assessing the welfare consequences of providing litter for feed-restricted broiler breeders

1. Broiler breeder females were fed restricted allocations of a standard wheat–soy ration to meet target body weights. They were housed on raised plastic slotted floors (S) or wood shavings litter (L) from hatch to 8 weeks when each pen of 12 birds was transferred to another pen in the same block in a 2 × 2 factorial experiment (LL, LS, SL and SS). Measures of bird welfare were taken at 4 weeks of age, and at 9 and 10 weeks following transfer to the new pens. 2. At 4 weeks of age, birds reared on S spent more time standing, pecking the feeder, the wall and other birds and less time pecking the floor compared with those on L. Gentle feather pecks, strong feather pecks and strong feather pulls were more common in S than L. 3. Mean body weight was higher and coefficient of variation lower in birds on L than S at the end of the experiment. Feather loss and damage scores at 10 weeks were higher for birds reared from hatch to 8 weeks on S. 4. Birds that were reared on S continued to peck more at the pen walls after transfer to new pens but there was no other carry-over effect on behaviour. Birds on S at 9 and 10 weeks pecked more at the walls and less often at the floor, and rested less often. There was more feather pecking on S than on L in the second week post transfer. 5. Tonic immobility was greater and plasma corticosterone concentrations were lower at the end of the experiment in birds on L than S at 9 and 10 weeks of age. The heterophil–lymphocyte ratio was similar between treatments at 4 weeks and after the birds were moved to a new pen. 6. The results are consistent with the view that litter and wall pecking has de-arousing properties and that this activity is re-directed foraging that diminishes the stress of feed restriction.

Umidade de equilíbrio de painéis de madeira

Este estudo teve como objetivo a determinação da umidade de equilíbrio de painéis de madeira numa câmara de climatização e comparação dos seus valores com os obtidos através da equação de Nelson. O trabalho foi desenvolvido na Unidade Experimental de Produção de Painéis de Madeira da Universidade Federal de Lavras. Foram utilizadas amostras de aglomerado, compensado multilaminado e sarrafeado, chapa dura, OSB (Oriented Strand Board) , MDF (Medium Density Fiberboard), HDF (High Density Fiberboard), madeira-cimento e madeira-plástico, sendo esses produtos de escala industrial e experimental. As dimensões dos corpos-de-prova foram de 2,60 cm de largura por 2,60 cm de comprimento. As espessuras foram aquelas mais utilizadas comercialmente de cada produto, sendo utilizadas cinco repetições por painel. Os corpos-de-prova foram pesados e levados para uma câmara de climatização, onde foram submetidos a diferentes condições de umidade relativa (90, 80, 70, 60, 50 e 40%) e uma temperatura constante de 30 ºC. Determinaram-se a histerese e a umidade de equilíbrio, que variaram de 40 a 90%. Os resultados indicaram que a equação de Nelson se mostrou eficiente na estimativa da umidade de equilíbrio e que não existe em média diferença de histerese entre os produtos estudados, mostrando que todos apresentam a mesma estabilidade dimensional. Observou-se, também, que o revestimento dos painéis não afetou a umidade de equilíbrio.

Experimental Investigation of Burning Scenario of Loaded 3.49-Ton Pickup Trucks

Five full-scale fire experiments on 3.49-ton pickup trucks with goods are described. The test variables used were the two kinds of goods - plastic barrels and wood pallets - and the two ignition positions - on the seat and at bottom center of the goods - in order to determine the basic burning behaviors of loaded pickup trucks. In addition, the fire compartment concept was adopted by covering the goods with a fire-resistant blanket and the goods were placed in. an iron trough. It is shown in two fire compartment concept tests that both wood and plastic goods continue to smolder with no blaze observed after ignition. The fire-resistant blanket and the iron trough in concert, are proved to be effective in fire control, reducing the radiation coming out of the burning goods and preventing the fire from spreading. Language: en

Design of wood/montmorillonite (MMT) intercalation nanocomposite

Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other disciplines. The compounding of wood and inorganic MMT on nanoscale molecular level has high potential to greatly improve the mechanical properties, fire retardance, abrasion resistance, decay resistance, dimensional stability and other properties of wood. Based on the great achievements of polymer/montmorillonite (MMT) nanocomposites, this paper reviewed nano intercalation compounding methods (i.e. in-situ intercalative polymerization and direct polymer intercalation), and discussed the structure, properties and modification of montmorillonite (MMT). According to the main chemical components and particular structure of wood, the authors discussed the liquefaction and plasticization of wood, compared the dissolvability and meltability between wood and polymer, and then systematically put forward the basic idea, technological processes and schematic diagram to prepare wood/MMT nanocomposites (WMNC). The key technology to prepare WMNC is either to introduce delaminated MMT nanolayers into wood with the help of some intermediate polymers, or to obtain liquefied wood or plasticized wood from the complicated natural composite. It is applicable and effective to realize wood/MMT nanoscale compounding with the help of proper intercalation agent and medium polymer through the proposed “one-step” or “two-step” impregnating processes.

木材と生分解性プラスチックのぬれ性について(材料の強度と力学的評価)

木材と生分解性プラスチックのぬれ性について(材料の強度と力学的評価)

712 ファインウッドの創製に関する研究 : 木材の可塑性を考慮した木質粉体の三次元成形についての検討

712 ファインウッドの創製に関する研究 : 木材の可塑性を考慮した木質粉体の三次元成形についての検討

Persistence and effectiveness of pyrethroids in plastic strips against Varroa jacobsoni (Acari: Varroidae) and mite resistance in a Mediterranean area.

An apiary trial was conducted in 1997 in Sardinia, Italy, to verify the effectiveness of fluvalinate in polyvinyl chloride strips and flumethrin in polyethylene strips against Varroa jacobsoni Oudemans. Two indices to evaluate the efficacy of the treatments were adopted: percentage change in mite infestation of worker-sealed brood cells considering only treated hives and percentage change in mite mortality, and the natural variation in mite populations recorded in control hives during the trial. All acaricide treatments reduced the level of mite infestation of both sealed brood and adult bees. However, their effectiveness was slightly reduced in comparison to previous studies because of mite resistance phenomena. Portions of polyethylene strips of flumethrin from treated hives were sampled weekly to determine acaricide persistence using gas chromatography. After 4 wk, a slight reduction (approximately 9%) of the active ingredient content was observed. A laboratory bioassay also was performed to establish the resistance of adult female mites to fluvalinate. Mites were sampled from the experimental apiary and from various Sardinian apiaries which had primarily been subjected to fluvalinate applications in plastic strips or wood inserts for years. Mite resistance varied from 0 to 96%, depending on the acaricide management adopted. The lowest resistance level occurred in an apiary where pyrethroids had never been used, whereas the highest level occurred in an apiary, with intensive use of fluvalinate in wood inserts.

Organic Fingerprint Powders Based on Fluorescent Phloxine B Dye.

Novel fingerpript powders based on organic dye (phJoxine B) have been prepared using insoluble salts as adhesive matrials in place of costly resinous polymers (which most conventional powders incorporate). Sharp and clear prints have been developed on a wide range of surfaces, such as paper, I plastic, glass, bakelite, enamelled metal and polished wood. The fluorescent nature of phloxine B assists in developing weak prints und.er ultraviolet light which can assist a forensic scientist for lifting fingerprints frqm the scene of crime and also a defence scientist for establishing the identity of deceased native soldiers as well as of prisoners of war.