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Sample records for broad wood cockroach

  1. Life history and habitat associations of the broad wood cockroach, Parcoblatta lata (Blattaria: Blattellidae) and other native cockroaches in the Coastal Plain of South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James, L.

    2002-06-18

    Wood cockroaches are an important prey of the red-cockaded woodpecker, Picoides borealis, an endangered species inhabiting pine forests in the southern United States. These woodpeckers forage on the boles of live pine trees, but their prey consists of a high proportion of wood cockroaches, Parcoblatta spp., that are more commonly associated with dead plant material. Cockroach population density samples were conducted on live pine trees, dead snags and coarse woody debris on the ground. The studies showed that snags and logs are also important habitats of wood cockroaches in pine forests.

  2. Nest sanitation through defecation: antifungal properties of wood cockroach feces

    Science.gov (United States)

    Rosengaus, Rebeca B.; Mead, Kerry; Du Comb, William S.; Benson, Ryan W.; Godoy, Veronica G.

    2013-11-01

    The wood cockroach Cryptocercus punctulatus nests as family units inside decayed wood, a substrate known for its high microbial load. We tested the hypothesis that defecation within their nests, a common occurrence in this species, reduces the probability of fungal development. Conidia of the entomopathogenic fungus, Metarhizium anisopliae, were incubated with crushed feces and subsequently plated on potato dextrose agar. Relative to controls, the viability of fungal conidia was significantly reduced following incubation with feces and was negatively correlated with incubation time. Although the cockroach's hindgut contained abundant β-1,3-glucanase activity, its feces had no detectable enzymatic function. Hence, these enzymes are unlikely the source of the fungistasis. Instead, the antifungal compound(s) of the feces involved heat-sensitive factor(s) of potential microbial origin. When feces were boiled or when they were subjected to ultraviolet radiation and subsequently incubated with conidia, viability was "rescued" and germination rates were similar to those of controls. Filtration experiments indicate that the fungistatic activity of feces results from chemical interference. Because Cryptocercidae cockroaches have been considered appropriate models to make inferences about the factors fostering the evolution of termite sociality, we suggest that nesting in microbe-rich environments likely selected for the coupling of intranest defecation and feces fungistasis in the common ancestor of wood cockroaches and termites. This might in turn have served as a preadaptation that prevented mycosis as these phylogenetically related taxa diverged and evolved respectively into subsocial and eusocial organizations.

  3. Functional symbiosis and communication in microbial ecosystems. The case of wood-eating termites and cockroaches.

    Science.gov (United States)

    Berlanga, Mercedes

    2015-09-01

    Animal hosts typically have strong specificity for microbial symbionts and their functions. The symbiotic relationships have enhanced the limited metabolic networks of most eukaryotes by contributing several prokaryotic metabolic capabilities, such as methanogenesis, chemolithoautotrophy, nitrogen assimilation, etc. This review will examine the characteristics that determine bacterial "fidelity" to certain groups of animals (e.g., xylophagous insects, such as termites and cockroaches) over generations and throughout evolution. The hindgut bacteria of wood-feeding termites and cockroaches belong to several phyla, including Proteobacteria, especially Deltaproteobacteria, Bacteroidetes, Firmicutes, Actinomycetes, Spirochetes, Verrucomicrobia, and Actinobacteria, as detected by 16S rRNA. Termites effectively feed on many types of lignocelluloses assisted by their gut microbial symbionts. Although the community structures differ between the hosts (termites and cockroaches), with changes in the relative abundances of particular bacterial taxa, the composition of the bacterial community could reflect at least in part the host evolution in that the microbiota may derive from the microbiota of a common ancestor. Therefore, factors other than host phylogeny, such as diet could have had strong influence in shaping the bacterial community structure. PMID:27036743

  4. Biogeography and Phylogeny of Wood-feeding Cockroaches in the Genus Cryptocercus

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    Kiyoto Maekawa

    2011-07-01

    Full Text Available Subsocial, xylophagous cockroaches of the genus Cryptocercus exhibit a disjunct distribution, with representatives in mature montane forests of North America, China, Korea and the Russian Far East. All described species are wingless and dependent on rotting wood for food and shelter at all stages of their life cycle; consequently, their distribution is tied to that of forests and strongly influenced by palaeogeographical events. Asian and American lineages form distinct monophyletic groups, comprised of populations with complex geographic substructuring. We review the phylogeny and distribution of Cryptocercus, and discuss splitting events inferred from molecular data.

  5. Cockroach Allergy

    Science.gov (United States)

    ... Allergies Disabilities? Allergies Types of Allergies Drug Allergy Food Allergy Insect Allergy Cockroach Allergy Dust Mite Allergy Latex Allergy ... Dust Mite Allergy Types of Allergies Drug Allergy Food Allergy Insect Allergy Latex Allergy Mold Allergy Pet Allergy Pollen ...

  6. Wood

    DEFF Research Database (Denmark)

    Unterrainer, Walter

    2014-01-01

    Wood – a sustainable building material ? For thousands of years and all over the planet, wood has been used as a building material and exciting architecture has been created in wood. The fantastic structural, physical and aesthetic properties of the material as well as the fact that wood...... is a renewable resource makes it predestinated for what is considered ´sustainable architecture´. But the reality is less linear and there are serious traps: In fact the lecture shows by examples that it is much easier to build very unsustainable buildings in wood than the other way round! Where does the wood...... has shrinked by 30% since the preindustrial times and in countries like China (with a historic tradition for wooden architecture) we could observe enormous desertification. What does this mean for the use of wood in modern architecture ? A critical reflection is needed. In too many cases...

  7. Calculating broad neutron resonances in a cut-off Woods-Saxon potential

    CERN Document Server

    Baran, Á; Salamon, P; Vertse, T

    2015-01-01

    In a cut-off Woods-Saxon potential with realistic depth $S$-matrix poles being far from the imaginary wave number axis form a sequence where the distances of the consecutive resonances are inversely proportional with the cut-off radius value. Other poles lying closer to the imaginary wave number axis might have trajectories with irregular shapes as the depth of the potential increases. Poles being close repel each other, and their repulsion is responsible for the changes of the directions of the corresponding trajectories. The interaction is extremely sensitive to the cut-off radius value. The repulsion might cause that certain resonances become antibound and later resonances again when they collide on the imaginary axis.

  8. Calculating broad neutron resonances in a cut-off Woods-Saxon potential

    Energy Technology Data Exchange (ETDEWEB)

    Baran, A.; Noszaly, Cs. [Faculty of Informatics, University of Debrecen, PO Box 12, Debrecen (Hungary); Salamon, P. [Hungarian Academy of Sciences (ATOMKI), Institute for Nuclear Research, PO Box 51, Debrecen (Hungary); Vertse, T. [Faculty of Informatics, University of Debrecen, PO Box 12, Debrecen (Hungary); Hungarian Academy of Sciences (ATOMKI), Institute for Nuclear Research, PO Box 51, Debrecen (Hungary)

    2015-07-15

    In a cut-off Woods-Saxon (CWS) potential with realistic depth S -matrix poles being far from the imaginary wave number axis form a sequence where the distances of the consecutive resonances are inversely proportional with the cut-off radius value, which is an unphysical parameter. Other poles lying closer to the imaginary wave number axis might have trajectories with irregular shapes as the depth of the potential increases. Poles being close repel each other, and their repulsion is responsible for the changes of the directions of the corresponding trajectories. The repulsion might cause that certain resonances become antibound and later resonances again when they collide on the imaginary axis. The interaction is extremely sensitive to the cut-off radius value, which is an apparent handicap of the CWS potential. (orig.)

  9. Molecular Characteristics of Cockroach Allergens

    Institute of Scientific and Technical Information of China (English)

    Chii-Huei Wu; Mey-Fann Lee

    2005-01-01

    Cockroaches, commonly found in urban dwellings worldwide, have long been considered vectors of various infectious diseases and cockroach allergens are one of the major etiologic risk factors for IgE-mediated allergic respiratory illness throughout the world. A high prevalence of cockroach hypersensitivity in atopic (20-55 %) and asthmatic (49-60%) populations has been documented. Cockroach allergens with molecular weights ranging from 6 to 120 kD have been identified by various standard immunochemical techniques. This article covers the characteristics of major cockroach allergens that have been purified, sequenced, cloned, and produced as recombinant proteins.

  10. DIVERSITY AND ECOLOGICAL DETERMINANTS OF DEAD WOOD FUNGI IN TREE NATURAL RESERVES OF BROAD LEAVED FORESTS FROM SUCEAVA COUNTY

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    Ciprian BÎRSAN

    2014-12-01

    Full Text Available Dead wood fungi have a major importance for forests biodiversity as they produce wood degradation in forest habitats. In this paper are presented some aspects related to the diversity of dead wood fungi in tree deciduous forest types from tree natural reserves (Crujana, Dragomirna and Zamostea from Suceava County and the effect of some ecological factors (host tree, diameter and decomposition degree of the dead wood and some microclimatic characteristics of sites on their occurrence and diversity. Investigations carried out in 2013 resulted in the identification of 44 lignicolous fungi species. Analysis of similarities between lingnicolous fungi species from the investigated natural reserves (by hierarchical clustering shows a separation of three fungi groups, depending on the host-trees species. The effect of the tree host species was highlighted also by detrended correspondence analysis, which, in addition presented the existence of an altitudinal gradient and a weaker effect of site conditions (slope and aspect and microclimatic variables (solar radiation on dead wood fungi occurrence. The effect of diameter and decomposition degree of fallen trunks and branches on dead wood fungi species was investigated using the redundancy analysis showing that wood debris with large surfaces are more easily colonized by the fungi species developing large sporocarps compared to small branches with low diameters colonized only by few or a single fungus species.

  11. Identification of cuticular lipids eliciting interspecific courtship in the German cockroach, Blattella germanica

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    Eliyahu, Dorit; Nojima, Satoshi; Capracotta, Sonja S.; Comins, Daniel L.; Schal, Coby

    2008-05-01

    The cuticular surface of sexually mature females of the German cockroach contains a sex pheromone that, upon contact with the male’s antennae, elicits a characteristic species-specific courtship behavior. This female-specific pheromone is a blend of several long-chain methyl ketones, alcohols and aldehydes, all derived from prominent cuticular hydrocarbons found in all life stages of this cockroach. We found that contact with the antennae of 5 out of 20 assayed cockroach species elicited courtship behavior in German cockroach males. The heterospecific courtship-eliciting compounds were isolated by behaviorally guided fractionation of the active crude extracts and compared to the native sex pheromone components. We identified two active compounds from the cuticular extract of the Oriental cockroach, Blatta orientalis—11-methylheptacosan-2-one and 27-oxo-11-methylheptacosan-2-one; the former compound was confirmed by synthesis and proved to independently stimulate courtship in German cockroach males. These compounds share common features with, but are distinct from, any of the known contact sex pheromone components. This suggests that sex pheromone reception in the male German cockroach is unusually promiscuous, accepting a wide range of compounds that share certain features with its native pheromone, thus resulting in a broad spectrum of behavioral response to other species. We propose that several characteristics of their mating system—chiefly, absence of closely related species in the anthropogenic environment, resulting in relaxation of selection on sexual communication, and a highly male-biased operational sex ratio—have driven males to respond with extremely low thresholds to a wide spectrum of related compounds.

  12. Cockroach as the Earliest Eusocial Animal

    Institute of Scientific and Technical Information of China (English)

    Peter VR(S)ANSK(Y)

    2010-01-01

    A completely preserved cockroach Sociala perlucida gen.et sp.nov.(Blattida:Socialidae fam.nov.) is described from the Mesozoic (Albian Early Cretaceous) amber of Archingeay in France.It is categorized within the new family Socialidae,originating from the Mesozoic cockroach family Liberiblattinidae,and representing the sister group to the most basal known eutermite families.Numerous direct and indirect morphological evidence (such as a unique narrow body and pronotum with reduced coloration,legs without carination and with numerous sensiilar pitts (forelegs) as adaptations to life in nests analogical to the living termitophillous species;enlarged head,long paips for communication,a general venation modified in a direction towards termites (subcosta and radial vein [R] approximated,R branches approximated,simplified,cross-veins reduced),and possibly also the development of the breaking forewing sutura for detaching wings after marriage flight),suggest its eusociai mode of life.Thus,the first eusociality originated within cockroaches,prior to giving birth to termites;termites and Cryptocercus are not directly related.The group of eusocial cockroaches makes termite morphotaxon polyphyletic,but also in this case,the erection of a new order for mastotermites (including Cratomastotermitidae) and/or the inclusion of eusocial,morphological cockroaches within termites appears counterproductive,thus an example of such a general exception to the taxonomical procedure is provided.

  13. On triatomines, cockroaches and haemolymphagy under laboratory conditions: new discoveries

    Science.gov (United States)

    Durán, Pamela; Siñani, Edda; Depickère, Stéphanie

    2016-01-01

    For a long time, haematophagy was considered an obligate condition for triatomines (Hemiptera: Reduviidae) to complete their life cycle. Today, the ability to use haemolymphagy is suggested to represent an important survival strategy for some species, especially those in genus Belminus. As Eratyrus mucronatus and Triatoma boliviana are found with cockroaches in the Blaberinae subfamily in Bolivia, their developmental cycle from egg to adult under a “cockroach diet” was studied. The results suggested that having only cockroach haemolymph as a food source compromised development cycle completion in both species. Compared to a “mouse diet”, the cockroach diet increased: (i) the mortality at each nymphal instar; (ii) the number of feedings needed to molt; (iii) the volume of the maximum food intake; and (iv) the time needed to molt. In conclusion, haemolymph could effectively support survival in the field in both species. Nevertheless, under laboratory conditions, the use of haemolymphagy as a survival strategy in the first developmental stages of these species was not supported, as their mortality was very high. Finally, when Triatoma infestans, Rhodnius stali and Panstrongylus rufotuberculatus species were reared on a cockroach diet under similar conditions, all died rather than feeding on cockroaches. These results are discussed in the context of the ecology of each species. PMID:27706376

  14. Multiple evolutionary origins of Australian soil-burrowing cockroaches driven by climate change in the Neogene.

    Science.gov (United States)

    Lo, Nathan; Tong, K Jun; Rose, Harley A; Ho, Simon Y W; Beninati, Tiziana; Low, David L T; Matsumoto, Tadao; Maekawa, Kiyoto

    2016-02-24

    Parallel evolution is the independent appearance of similar derived phenotypes from similar ancestral forms. It is of key importance in the debate over whether evolution is stochastic and unpredictable, or subject to constraints that limit available phenotypic options. Nevertheless, its occurrence has rarely been demonstrated above the species level. Climate change on the Australian landmass over the last approximately 20 Myr has provided conditions conducive to parallel evolution, as taxa at the edges of shrinking mesic habitats adapted to drier biomes. Here, we investigate the phylogeny and evolution of Australian soil-burrowing and wood-feeding blaberid cockroaches. Soil burrowers (subfamily Geoscapheinae) are found in relatively dry sclerophyllous and scrubland habits, whereas wood feeders (subfamily Panesthiinae) are found in rainforest and wet sclerophyll. We sequenced and analysed mitochondrial and nuclear markers from 142 specimens, and estimated the evolutionary time scale of the two subfamilies. We found evidence for the parallel evolution of soil-burrowing taxa from wood-feeding ancestors on up to nine occasions. These transitions appear to have been driven by periods of aridification during the Miocene and Pliocene across eastern Australia. Our results provide an illuminating example of climate-driven parallel evolution among species. PMID:26888035

  15. Prevalence of sensitivity to cockroach allergens and IgE crossreactivity between cockroach and house dust mite allergens in Chinese patients with allergic rhinitis and asthma

    Institute of Scientific and Technical Information of China (English)

    SUN Bao-qing; LAI Xu-xin; Birgitte Gjesing; Michael Dho Spangfort; ZHONG Nan-shan

    2010-01-01

    Background Cockroaches are an important indoor allergen source causing allergic rhinitis and asthma. The aim of this study was to investigate the cockroach prevalence in mainland of China and the cross-reactivity of IgE between cockroach and house dust mite allergen in Chinese patients.Methods The cockroach sensitization pattern was based on a skin prick test (SPT) obtained from a national multicenter prevalence study, in which 6304 patients from 25 allergy centers across China participated. Factors, including different regions of China, age, gender and the correlations between the American and German cockroaches and house dust mite Der p were investigated. Eighteen out of 1236 clinical sera from south China were selected to perform the cross-inhibition assay between house dust mites and cockroaches.Results Totally 25.7% of patients were SPT positive to the American cockroach (Periplaneta Americana, Per a) and 18.7% SPT positive to the German cockroach (Blattella germanica, Bla g). The prevalence of positive cockroach SPT was higher in southern than in northern China, higher in adults than in children, and higher in males than in females.Patients had relatively low levels of cockroach SPT reactions, mainly class 1 or 2. Of the SPT positive cockroach patients,88% were also SPT positive to house dust mite (Dermatophagoides pteronyssinus, Der p). An IgE cross-inhibition study confirmed that Der P sensitization could cause false positive SPT reactions against cockroach.Conclusions A relatively high prevalence of cockroach sensitivity was found in mainland of China. However, a cross-inhibition study showed that only a small number of patients appear to have Bla g and/or Per a as primary sensitizing source. The importance of cockroaches as a risk factor for sensitization and triggers of allergic symptoms in mainland of China needs to be further investigated.

  16. 闽北天然阔叶林径阶材种结构分析及出材率表的编制%Compilation of Output Structure of Diameter Grade Wood Assortments and Volume Ratio Table for Natural Broad-Leaved Forest Tree Species in North Fujian Province

    Institute of Scientific and Technical Information of China (English)

    李晓景; 江希钿; 庄崇洋; 李小铃

    2012-01-01

    应用闽北天然阔叶林现场造材资料,在分析径阶材种结构规律的基础上,选择适合的方程建立材种出材率模型并编制二元材种出材率表.经检验,该表精度较高,在林业生产上有实用价值.为方便生产中应用,还建立了树高曲线模型,由二元材种出材率袁导出了一元材种出材率表.%The volume ratio model of wood assortment was built by choosing the proper equation, and the two dimension merchantable wood assortment volume yielding rate tables were compiled based on structure analyses of diameter grade wood assortments, with on the spot sample timber data collected from the natural broad-leaved forests in the north Fujian Province. The wood assortment volume yielding rate tables were tested to be with high precision and practicable in forestry production. In order to facilitate the production and application, tree height model was established, and the one dimension merchantable wood assortment volume yielding rate tables were derived from the two dimension tables.

  17. Mechanical transmission of pathogenic organisms: the role of cockroaches

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    Y.M. Tatfeng, M.U. Usuanlele, A. Orukpe, A.K. Digban, M. Okodua,F. Oviasogie & A.A. Turay

    2005-12-01

    Full Text Available Background & objectives: Cockroaches (Diploptera punctata are basically tropical insects and willdo their best to find a home that is both warm and moist. Their involvement in the transmission oftropical diseases is poorly investigated in Africa.Methods: A study on the bacterial, fungal and parasitic profile of cockroaches trapped in and aroundhouses in Ekpoma was carried out using standard microbiological techniques.Results: Of a total of 234 cockroaches trapped from different sites (toilets, parlours, kitchens andbedrooms in houses with pit latrines and water system, the bacterial, fungal and parasitic isolateswere identical irrespective of the site, these included: E. coli, Klebsiella pneumoniae, Proteus vulgaris,Proteus mirabilis, Citrobacter freundii, Enterobacter cloacae, Salmonella sp, Pseudomonasaeruginosa, Serretia marcescens, S. aureus, S. feacalis, S. epidermidis, Aeromonas sp, Candida sp,Rhizopus sp, Aspergillus sp, Mucor sp, cysts of E. hystolitica, oocysts of C. parvum, C. cayetenensisand Isospora belli, cysts of Balantidium coli, ova of Ascaris lumbricoides, Anchylostoma deodunalae,Enterobius vermicularis, ova Trichuris trichura, larva of Strongyloides stercoralis. Cockroachestrapped in the toilets of houses with pit latrines had a mean bacterial and parasites count of12.3 × 1010 org/ml and 98 parasites/ml respectively, while those trapped in the houses with watersystem had a mean bacterial and parasitic count of 89.5 × 107 org/ml and 31 parasites/ml respectively.A bacterial count of 78.9 × 107 org/ml was recorded from cockroaches trapped from the kitchens ofhouses with pit latrines. On the other hand a mean bacterial and parasitic count of 23.7 × 106 org/mland 19 parasites/ml were recorded from kitchens of houses with water system.Interpretation & conclusion: Cockroaches represent an important reservoir for infectious pathogens,therefore, control of cockroaches will substantially minimise the spread of infectious diseases

  18. The evaporative function of cockroach hygroreceptors.

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    Harald Tichy

    Full Text Available Insect hygroreceptors associate as antagonistic pairs of a moist cell and a dry cell together with a cold cell in small cuticular sensilla on the antennae. The mechanisms by which the atmospheric humidity stimulates the hygroreceptive cells remain elusive. Three models for humidity transduction have been proposed in which hygroreceptors operate either as mechanical hygrometers, evaporation detectors or psychrometers. Mechanical hygrometers are assumed to respond to the relative humidity, evaporation detectors to the saturation deficit and psychrometers to the temperature depression (the difference between wet-bulb and dry-bulb temperatures. The models refer to different ways of expressing humidity. This also means, however, that at different temperatures these different types of hygroreceptors indicate very different humidity conditions. The present study tested the adequacy of the three models on the cockroach's moist and dry cells by determining whether the specific predictions about the temperature-dependence of the humidity responses are indeed observed. While in previous studies stimulation consisted of rapid step-like humidity changes, here we changed humidity slowly and continuously up and down in a sinusoidal fashion. The low rates of change made it possible to measure instantaneous humidity values based on UV-absorption and to assign these values to the hygroreceptive sensillum. The moist cell fitted neither the mechanical hygrometer nor the evaporation detector model: the temperature dependence of its humidity responses could not be attributed to relative humidity or to saturation deficit, respectively. The psychrometer model, however, was verified by the close relationships of the moist cell's response with the wet-bulb temperature and the dry cell's response with the dry-bulb temperature. Thus, the hygroreceptors respond to evaporation and the resulting cooling due to the wetness or dryness of the air. The drier the ambient air

  19. Binary Cockroach Swarm Optimization for Combinatorial Optimization Problem

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    Ibidun Christiana Obagbuwa

    2016-09-01

    Full Text Available The Cockroach Swarm Optimization (CSO algorithm is inspired by cockroach social behavior. It is a simple and efficient meta-heuristic algorithm and has been applied to solve global optimization problems successfully. The original CSO algorithm and its variants operate mainly in continuous search space and cannot solve binary-coded optimization problems directly. Many optimization problems have their decision variables in binary. Binary Cockroach Swarm Optimization (BCSO is proposed in this paper to tackle such problems and was evaluated on the popular Traveling Salesman Problem (TSP, which is considered to be an NP-hard Combinatorial Optimization Problem (COP. A transfer function was employed to map a continuous search space CSO to binary search space. The performance of the proposed algorithm was tested firstly on benchmark functions through simulation studies and compared with the performance of existing binary particle swarm optimization and continuous space versions of CSO. The proposed BCSO was adapted to TSP and applied to a set of benchmark instances of symmetric TSP from the TSP library. The results of the proposed Binary Cockroach Swarm Optimization (BCSO algorithm on TSP were compared to other meta-heuristic algorithms.

  20. Transcriptional control of behavior: Engrailed knockout changes cockroach escape trajectories

    OpenAIRE

    Booth, David; Marie, Bruno; Domenici, Paolo; Blagburn, Jonathan M.; Bacon, Jonathan P.

    2009-01-01

    The cerci of the cockroach are covered with identified sensory hairs, which detect air movements. The sensory neurons which innervate these hairs synapse with giant interneurons (GIs) in the terminal ganglion which in turn synapse with interneurons and leg motorneurons in thoracic ganglia. This neural circuit mediates the animal's escape behavior. The transcription factor Engrailed (En) is expressed only in the medially born sensory neurons, which suggested it could work as a positional deter...

  1. Protease activity in cockroach and basidiomycete allergen extracts.

    Science.gov (United States)

    Wongtim, S; Lehrer, S B; Salvaggio, J E; Horner, W E

    1993-01-01

    Inherent proteolytic activity was estimated in cockroach and basidiomycete extracts by quantifying acid soluble peptides that were released by incubating extracts with 1% bovine serum albumin as measured by Lowry (Sigma). Reference proteases released 740 (Proteinase K, 0.1 U), 248 (Trypsin, 1.0 U), and 533 micrograms/ml (Pronase, 0.5 U) of soluble peptides. American whole body cockroach extract (0.1 mg dry weight) released 330 micrograms/ml of soluble peptides, representing 13 trypsin equivalent units (TEU)/mg. Extracts from spores of the mushroom Pleurotus ostreatus released 230 micrograms/ml (0.9 TEU/mg) and Pleurotus cap extract released 112 micrograms/ml (0.5 TEU/mg). Mycelium of Pleurotus and the mushroom Psilocybe cubensis and spores of Psilocybe and the puffball Calvatia cyathiformis showed negligible amounts of proteolytic activity. The protease inhibitor phenylmethylsulfonyl flouride reduced the proteolytic activity of American whole body cockroach extract by 80% (@1 mM) and the inhibitor ethylene diaminetetraacetic acid inhibited the proteolytic activity of Pleurotus spores by 95% (@1 mM). Loss of allergen activity as determined by RAST inhibition and immunoprinting correlated with protease activity. Thus, in the preparation and handling of allergen extracts, one should employ conditions that minimize proteolysis.

  2. De novo transcriptome of the Hemimetabolous German cockroach (Blattella germanica.

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    Xiaojie Zhou

    Full Text Available BACKGROUND: The German cockroach, Blattella germanica, is an important insect pest that transmits various pathogens mechanically and causes severe allergic diseases. This insect has long served as a model system for studies of insect biology, physiology and ecology. However, the lack of genome or transcriptome information heavily hinder our further understanding about the German cockroach in every aspect at a molecular level and on a genome-wide scale. To explore the transcriptome and identify unique sequences of interest, we subjected the B. germanica transcriptome to massively parallel pyrosequencing and generated the first reference transcriptome for B. germanica. METHODOLOGY/PRINCIPAL FINDINGS: A total of 1,365,609 raw reads with an average length of 529 bp were generated via pyrosequencing the mixed cDNA library from different life stages of German cockroach including maturing oothecae, nymphs, adult females and males. The raw reads were de novo assembled to 48,800 contigs and 3,961 singletons with high-quality unique sequences. These sequences were annotated and classified functionally in terms of BLAST, GO and KEGG, and the genes putatively coding detoxification enzyme systems, insecticide targets, key components in systematic RNA interference, immunity and chemoreception pathways were identified. A total of 3,601 SSRs (Simple Sequence Repeats loci were also predicted. CONCLUSIONS/SIGNIFICANCE: The whole transcriptome pyrosequencing data from this study provides a usable genetic resource for future identification of potential functional genes involved in various biological processes.

  3. Survey of Optimal Methods for the Control of Cockroaches in Sewers of Qom City

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    H. Bakhtiari

    2010-04-01

    Full Text Available "n "nBackgrounds and Objectives: Domestic sewers and wastewater treatment plants are suitable places for the growth of some types of Cockroaches. Annually the water and wastewater company of Qom city make considerable attempts to overwhelm the problem. The current study is aimed to determine types of Cockroaches and select the optimal methods for their control."nMaterials andMethods: In this study, 120 manholes are selected in different locations of Qom city, the numbers of Cockroaches are counted and the Cockroaches are classified into different groups. Then, each group are faced to different insecticides Including Simperator, Diazinon , Dursban Ec, Faikam, Sipermetrin, Icon, Deltametrina and Sulfac. One group of manholes was considered as blank sample during one month. Counting and determination of Cockroaches in these manholes conducted before using insecticides and also five months after it."nResults: the study showed that all sewers were 100% polluted by Cockroaches. The number of Cockroaches in manholes range from minimum 4 to maximum 3600 in each manhole. The applied of insecticides including Dursban Ec, Simperator, Sulfac, Dursban, and Deltametrina are used 2 gr in 100 square meter of area of each sewer. The Cockroaches population reduced to approximately zero after application of these insecticides. Spraying sewers by Simperator controlled 100% of Cockroaches."nConclusion: the most effective method for the control of Cockroaches was usage of 2 gr of Dursban (Ec in squaremeter of area in the beginning of warmseason.If we use 1-1/5months interval between the time of spraying insecticide in selected wells, with using simperator and dursban (Ec we can overwhelm Cockroaches using Simperator and Dursban Ec. The results of statistical analysis show that reduction of number of coackroaches in one month after using poison is significant (P-value< 0.05. But after 5months it lose meaningful in all of them.Also, reduction of number of

  4. Research on data storage CockroachDB Docker application technology%数据存储CockroachDB应用技术Docker的研究

    Institute of Scientific and Technical Information of China (English)

    谷雨

    2015-01-01

    CockroachDB将构造一个伸缩性强、分布式的数据库,使用Docker来自动化、流程化开发、测试和部署过程.且不需要安装任何程序就可以学习到如何部署Cockroach,并且在任何系统中部署可靠的、最小化的容器.

  5. <> embodiment of cockroach behaviour in a micro-robot

    OpenAIRE

    Jost, Christian; Garnier, Simon; Jeanson, Raphaël; Asadpour, Masoud; Gautrais, Jacques; Theraulaz, Guy

    2004-01-01

    Autonomous robots may some day be able to behave like an animal, be accepted by the animal as a conspecific and influence the individual as well as the collective behaviour of the animal and its conspecifics. With this objective in mind we report here the results of the first step in this direction, making the robot move like an animal. We programmed the Alice (sugar-cube) robot to behave qualitatively like a cockroach (random walk with wall-following behaviour). We then analyzed Alice displa...

  6. [Asymmetry of antennal grooming in the cockroach (Periplaneta americana)].

    Science.gov (United States)

    2014-07-01

    The present study was conducted to determine the key features of antennal grooming of male American cockroaches in neutral circumstances. It was shown for the first time that the right antenna was cleaned significantly more often than the left one, which indicates the presence of functional asymmetry of antennal grooming in this insect species. At the same time, no statistically significant asymmetry was found for grooming of antennal bases and legs. Morphological asymmetries of antennae and legs and/or brain lateralization are the plausible sources of observed behavioral asymmetry in antennal grooming.

  7. Aryl Hydrocarbon Receptor Protects Lungs from Cockroach Allergen-Induced Inflammation by Modulating Mesenchymal Stem Cells.

    Science.gov (United States)

    Xu, Ting; Zhou, Yufeng; Qiu, Lipeng; Do, Danh C; Zhao, Yilin; Cui, Zhuang; Wang, Heng; Liu, Xiaopeng; Saradna, Arjun; Cao, Xu; Wan, Mei; Gao, Peisong

    2015-12-15

    Exposure to cockroach allergen leads to allergic sensitization and increased risk of developing asthma. Aryl hydrocarbon receptor (AhR), a receptor for many common environmental contaminants, can sense not only environmental pollutants but also microbial insults. Mesenchymal stem cells (MSCs) are multipotent progenitor cells with the capacity to modulate immune responses. In this study, we investigated whether AhR can sense cockroach allergens and modulate allergen-induced lung inflammation through MSCs. We found that cockroach allergen-treated AhR-deficient (AhR(-/-)) mice showed exacerbation of lung inflammation when compared with wild-type (WT) mice. In contrast, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an AhR agonist, significantly suppressed allergen-induced mouse lung inflammation. MSCs were significantly reduced in cockroach allergen-challenged AhR(-/-) mice as compared with WT mice, but increased in cockroach allergen-challenged WT mice when treated with TCDD. Moreover, MSCs express AhR, and AhR signaling can be activated by cockroach allergen with increased expression of its downstream genes cyp1a1 and cyp1b1. Furthermore, we tracked the migration of i.v.-injected GFP(+) MSCs and found that cockroach allergen-challenged AhR(-/-) mice displayed less migration of MSCs to the lungs compared with WT. The AhR-mediated MSC migration was further verified by an in vitro Transwell migration assay. Epithelial conditioned medium prepared from cockroach extract-challenged epithelial cells significantly induced MSC migration, which was further enhanced by TCDD. The administration of MSCs significantly attenuated cockroach allergen-induced inflammation, which was abolished by TGF-β1-neutralizing Ab. These results suggest that AhR plays an important role in protecting lungs from allergen-induced inflammation by modulating MSC recruitment and their immune-suppressive activity. PMID:26561548

  8. Rapid Elimination of German Cockroach, Blatella germanica, by Fipronil and Imidacloprid Gel Baits

    Directory of Open Access Journals (Sweden)

    H Nasirian

    2008-06-01

    Full Text Available Background: Baits have become popular and effective formulations against urban insect pests. Compared with re­sidual sprays toxic gel baits are used more and more frequently to control urban cockroach populations. The aim of this study was to investigate the usage of two commercially available fipronil and imidacloprid gel bait formulations against Blattella germanica field infested in Iran.Methods:  The study was carried out in an urban area at Tehran from March 2004 to September 2005. The 0.05% fipronil and 2.15% imidacloprid gel baits were placed continuously in 3 residential German cockroach infested units. Pre- and post-treatment cockroach density was assessed by visual count method.Results: Pre- and post-treatment visual count of cockroaches in treatment and control areas, and percentage reduc­tion in cockroach density in treatment areas in comparison to control areas was showed that density reduction was increased with the 0.05% fipronil and 2.15% imidacloprid gel baits in treated areas from 1st to 9th week in compari­son to control area. After 60 days, German cockroaches eliminated completely from these areas.Conclusion: These results show that fipronil and imidacloprid gel baits are highly effective in field German cock­roach infested after insecticide spraying control failure German cockroach infested fields where spraying  of pyrethroid insecticides failed to control the situation and confirm previous  reports stating that avermectin and hydramethylnon are more effective than conventional insecticides in baits against cockroaches. Therefore, fipronil and imidacloprid gel baits are appropriate candidates for controlling German cockroach infested dwellings in Iran where control with other insectices failed because of resistance.

  9. Pavlov's cockroach: classical conditioning of salivation in an insect.

    Directory of Open Access Journals (Sweden)

    Hidehiro Watanabe

    Full Text Available Secretion of saliva to aid swallowing and digestion is an important physiological function found in many vertebrates and invertebrates. Pavlov reported classical conditioning of salivation in dogs a century ago. Conditioning of salivation, however, has been so far reported only in dogs and humans, and its underlying neural mechanisms remain elusive because of the complexity of the mammalian brain. We previously reported that, in cockroaches Periplaneta americana, salivary neurons that control salivation exhibited increased responses to an odor after conditioning trials in which the odor was paired with sucrose solution. However, no direct evidence of conditioning of salivation was obtained. In this study, we investigated the effects of conditioning trials on the level of salivation. Untrained cockroaches exhibited salivary responses to sucrose solution applied to the mouth but not to peppermint or vanilla odor applied to an antenna. After differential conditioning trials in which an odor was paired with sucrose solution and another odor was presented without pairing with sucrose solution, sucrose-associated odor induced an increase in the level of salivation, but the odor presented alone did not. The conditioning effect lasted for one day after conditioning trials. This study demonstrates, for the first time, classical conditioning of salivation in species other than dogs and humans, thereby providing the first evidence of sophisticated neural control of autonomic function in insects. The results provide a useful model system for studying cellular basis of conditioning of salivation in the simpler nervous system of insects.

  10. Cockroaches (Insecta, Blattodea from caves of Polillo Island (Philippines, with description of a new species

    Directory of Open Access Journals (Sweden)

    Cristian C. Lucanas

    2016-09-01

    Full Text Available Cockroaches collected during a protracted series of fieldwork in several limestone caves in Polillo Island, Philippines were taxonomically studied. A new species of Nocticola (Nocticolidae, N. gonzalezi Lucañas & Lit, sp. n., is described. The male of Periplaneta banksi Hanitsch (Blattidae is described for the first time. Altogether, the present cave cockroach fauna of the island consists of six species.

  11. Grooming behavior in American cockroach is affected by novelty and odor.

    Science.gov (United States)

    Zhukovskaya, Marianna I

    2014-01-01

    The main features of grooming behavior are amazingly similar among arthropods and land vertebrates and serve the same needs. A particular pattern of cleaning movements in cockroaches shows cephalo-caudal progression. Grooming sequences become longer after adaptation to the new setting. Novelty related changes in grooming are recognized as a form of displacement behavior. Statistical analysis of behavior revealed that antennal grooming in American cockroach, Periplaneta americana L., was significantly enhanced in the presence of odor.

  12. Deterministic Assembly of Complex Bacterial Communities in Guts of Germ-Free Cockroaches.

    Science.gov (United States)

    Mikaelyan, Aram; Thompson, Claire L; Hofer, Markus J; Brune, Andreas

    2016-02-01

    The gut microbiota of termites plays important roles in the symbiotic digestion of lignocellulose. However, the factors shaping the microbial community structure remain poorly understood. Because termites cannot be raised under axenic conditions, we established the closely related cockroach Shelfordella lateralis as a germ-free model to study microbial community assembly and host-microbe interactions. In this study, we determined the composition of the bacterial assemblages in cockroaches inoculated with the gut microbiota of termites and mice using pyrosequencing analysis of their 16S rRNA genes. Although the composition of the xenobiotic communities was influenced by the lineages present in the foreign inocula, their structure resembled that of conventional cockroaches. Bacterial taxa abundant in conventional cockroaches but rare in the foreign inocula, such as Dysgonomonas and Parabacteroides spp., were selectively enriched in the xenobiotic communities. Donor-specific taxa, such as endomicrobia or spirochete lineages restricted to the gut microbiota of termites, however, either were unable to colonize germ-free cockroaches or formed only small populations. The exposure of xenobiotic cockroaches to conventional adults restored their normal microbiota, which indicated that autochthonous lineages outcompete foreign ones. Our results provide experimental proof that the assembly of a complex gut microbiota in insects is deterministic. PMID:26655763

  13. Gut Bacterial Community of the Xylophagous Cockroaches Cryptocercus punctulatus and Parasphaeria boleiriana.

    Science.gov (United States)

    Berlanga, Mercedes; Llorens, Carlos; Comas, Jaume; Guerrero, Ricardo

    2016-01-01

    Cryptocercus punctulatus and Parasphaeria boleiriana are two distantly related xylophagous and subsocial cockroaches. Cryptocercus is related to termites. Xylophagous cockroaches and termites are excellent model organisms for studying the symbiotic relationship between the insect and their microbiota. In this study, high-throughput 454 pyrosequencing of 16S rRNA was used to investigate the diversity of metagenomic gut communities of C. punctulatus and P. boleiriana, and thereby to identify possible shifts in symbiont allegiances during cockroaches evolution. Our results revealed that the hindgut prokaryotic communities of both xylophagous cockroaches are dominated by members of four Bacteria phyla: Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. Other identified phyla were Spirochaetes, Planctomycetes, candidatus Saccharibacteria (formerly TM7), and Acidobacteria, each of which represented 1-2% of the total population detected. Community similarity based on phylogenetic relatedness by unweighted UniFrac analyses indicated that the composition of the bacterial community in the two species was significantly different (P termites and other cockroaches, but not with those from other animals or environments. These results suggest that, during their evolution, those cockroaches conserved several bacterial communities from the microbiota of a common ancestor. The ecological stability of those microbial communities may imply the important functional role for the survival of the host of providing nutrients in appropriate quantities and balance. PMID:27054320

  14. [The yeast community associated with the digestive tract of the German cockroach Blattella germanica L].

    Science.gov (United States)

    Zheltikova, T M; Glushakova, A M; Alesho, N A

    2011-01-01

    Data on the yeasts colonizing the digestive tract ofa German cockroach have been first obtained. Cockroach cultures are used in the commercial production of allergy vaccines to treat patients sensitized to cockroach allergens. The enteric microflora of the insects can bring nonshared antigens into the composition of the agents manufactured. An investigation established that out of 10 yeast species isolated from the digestive tract of the cockroaches fed sterile food, 6 species (Candida glabrata, Cryptococcus magnus, Debaryomyces hansenii, Metschikowia pulcherrima, Phodo-torula glutinis, Rhodotorula mucilaginosa) were isolated from both the digestive tract and excrements and 4 (Candida oleophila, Candida shehatae, Cryptococcus albidus, Pichia membmnaefciens) were only from the digestive tract. It seems that the yeast is either digested or inactivated in the digestive tract of the insects and loses their capacity to grow When the cockroaches were fed sterile food for a long time (at least a month), all yeasts virtually disappeared from the digestive tract of the insects except for Candida glabrata, C.shehatae, and Rh.mucilaginosa. However, only C.glabrata achieved a great deal (10(7)-10(8) CFU/g) of cockroaches (both imagoes and larvae of 5-7 ages), which statistically significantly decreased by no less than three orders of magnitude in the excrements after passing through the digestive tract.

  15. Three dimensional analysis of the pore space in fine-grained Boom Clay, using BIB-SEM (broad-ion beam scanning electron microscopy), combined with FIB (focused ion-beam) serial cross-sectioning, pore network modeling and Wood's metal injection

    Science.gov (United States)

    Hemes, Susanne; Klaver, Jop; Desbois, Guillaume; Urai, Janos

    2014-05-01

    The Boom Clay is, besides the Ypresian clays, one of the potential host rock materials for radioactive waste disposal in Belgium (Gens et al., 2003; Van Marcke & Laenen, 2005; Verhoef et al., 2011). To access parameters, which are relevant for the diffusion controlled transport of radionuclides in the material, such as porosity, pore connectivity and permeability, it is crucial to characterize the pore space at high resolution (nm-scale) and in 3D. Focused-ion-beam (FIB) serial cross-sectioning in combination with high resolution scanning electron microscopy (SEM), pore network modeling, Wood's metal injection and broad-ion-beam (BIB) milling, constitute a superior set of methods to characterize the 3D pore space in fine-grained, clayey materials, down to the nm-scale resolution. In the present study, we identified characteristic 3D pore space morphologies, determined the 3D volume porosity of the material and applied pore network extraction modeling (Dong and Blunt, 2009), to access the connectivity of the pore space and to discriminate between pore bodies and pore throats. Moreover, we used Wood's metal injection (WMI) in combination with BIB-SEM imaging to assess the pore connectivity at a larger scale and even higher resolution. The FIB-SEM results show a highly (~ 90 %) interconnected pore space in Boom Clay, down to the resolution of ~ 3E+03 nm³ (voxel-size), with a total volume porosity of ~ 20 %. Pore morphologies of large (> 5E+08 nm³), highly interconnected pores are complex, with high surface area to volume ratios (shape factors G ~ 0.01), whereas small (areas (REAs) (Hemes et al., 2013).

  16. Microbial organisms carried by brown-banded cockroaches in relation to their spatial distribution in a hospital.

    OpenAIRE

    Le Guyader, A.; Rivault, C.; Chaperon, J

    1989-01-01

    A simultaneous study of cockroach (Supella supellectilium) distribution and of associated carried bacterial flora has been made in the main hospital in Rennes (France). Wild cockroaches carry a high number of bacterial species that can be related to the normal environmental flora and a contaminant flora acquired from particular environments. The diversity of carried bacterial species reveals a proximity factor between continguous floors of the building which leads us to suppose that cockroach...

  17. Laboratory and Field Evaluation of Zyrox Fly Granular Bait Against Asian and German Cockroaches (Dictyoptera: Blattellidae).

    Science.gov (United States)

    Matos, Yvonne K; Schal, Coby

    2016-08-01

    The Asian cockroach (Blattella asahinai Mizukubo) was introduced to Florida in 1986 and has since spread throughout the Southeastern United States. Blattella asahinai is a peridomestic pest and high population densities in residential areas can become a nuisance, especially when adults fly into homes. Few studies to date have been conducted on Asian cockroach control, and we evaluated the efficacy of Zyrox Fly Granular Bait and Maxforce Complete Granular Insect Bait against this species in the laboratory compared with the closely related German cockroach (Blattella germanica (L.)). In no-choice and two-choice assays with both species, Zyrox bait and Maxforce bait achieved nearly 100% mortality within two and five days, respectively. We also tested Zyrox bait against B. asahinai in an invasive field population in North Carolina at the label rate (2 g/m(2)) and at approximately three times the label rate (6.9 g/m(2)), and found that broadcast applications at both rates reduced populations by an average of 64 and 92%, respectively, for 35 d after the initial application. Zyrox Fly Bait appears to be effective against the Asian and German cockroaches, and could be another tool in an integrated pest management program, if its label could be extended or the active ingredient (cyantraniliprole) formulated into a cockroach bait. PMID:27122494

  18. Evaluation of Five Local Formulated Insecticides against German Cockroach (Blattella germanica L. in Southern Iran

    Directory of Open Access Journals (Sweden)

    M Shahi

    2008-06-01

    Full Text Available Background: The German cockroach, Blattella germanica L., is a serious household and public health pest worldwide. Con­trol of this species has been very difficult to achieve. Toxicity of cypermethrin EC10%, deltamethrin EC5%, diazi­non EC0.5%, lambda-cyhalothrin EC5% and Negon® (permethrin+propoxur oil liquid1% commercial for­mula­tions were investigated against adult males of German cockroaches collected from four hospitals of Bandar Abbas City, southern Iran, during 2006. These insecticides have been used for cockroach con­trol in this city.Methods: The tests were carried out only on males by the glass jar contact method recommended by the WHO.Results: Maximum mortality rates of 20, 35, 90, and 100% were obtained after one hour contact to label-recom­mended doses of cypermethrin, deltamethrin, lambad-cyhalothrin, diazinon and permethrin+propoxur insecti­cides, respectively. KT50 results were different from 5.68 min for permethrin+propoxur mixture to 240.37 min for cyper­methrin. German cockroach showed < 80 per cent mortality using three pyrethroid insecticides.Conclusion: It seems that the label-recommended concentrations of these insecticides were wrong and lower than WHO advised for cockroach control. For monitoring of resistance it is recommended to do more tests using the pure ac­tive ingredient of these insecticides.

  19. Evaluation of Five Local Formulated Insecticides against German Cockroach (Blattella germanica L. in Southern Iran

    Directory of Open Access Journals (Sweden)

    M Shahi

    2008-08-01

    Full Text Available Background: The German cockroach, Blattella germanica L., is a serious household and public health pest worldwide. Con­trol of this species has been very difficult to achieve. Toxicity of cypermethrin EC10%, deltamethrin EC5%, diazi­non EC0.5%, lambda-cyhalothrin EC5% and Negon® (permethrin+propoxur oil liquid1% commercial for­mula­tions were investigated against adult males of German cockroaches collected from four hospitals of Bandar Abbas City, southern Iran, during 2006. These insecticides have been used for cockroach con­trol in this city. Methods: The tests were carried out only on males by the glass jar contact method recommended by the WHO. Results: Maximum mortality rates of 20, 35, 90, and 100% were obtained after one hour contact to label-recom­mended doses of cypermethrin, deltamethrin, lambad-cyhalothrin, diazinon and permethrin+propoxur insecti­cides, respectively. KT50 results were different from 5.68 min for permethrin+propoxur mixture to 240.37 min for cyper­methrin. German cockroach showed < 80 per cent mortality using three pyrethroid insecticides. Conclusion: It seems that the label-recommended concentrations of these insecticides were wrong and lower than WHO advised for cockroach control. For monitoring of resistance it is recommended to do more tests using the pure ac­tive ingredient of these insecticides.

  20. Habitat influences on diversity of bacteria found on German cockroach in Beijing

    Institute of Scientific and Technical Information of China (English)

    FU Xue; YE Lefu; GE Feng

    2009-01-01

    Cockroaches are worldwide indoor pests carrying microorganisms of medical importance.German cockroaches (Blattella germanica) were sampled in five habitats (hospital, restaurant, office home, and market) in Beijing, and the bacteria were isolated from their external surface and alimentary tract and identified using a Biolog identification system.Cockroach densities significantly differed among habitats (market > home > office > restaurant > hospital).However, no significant differences in bacterial abundance carried by individual German cockroaches (of either sex) were found among habitats.The bacterial abundance in the gut was significantly higher than that on the surface.There were no significant differences in bacterial species richness observed among habitats, sex, carrying position or their interaction.Cluster analysis showed that cockroach densities and bacterial abundance found in the market differed significantly from the other four habitats.The bacterial diversity was not significantly reduced in sensitive facilities such as hospital and restaurant, even though pesticide and bactericide were more frequently applied there.The implications of these findings were discussed in this article.

  1. Robert Wood Johnson Foundation

    Science.gov (United States)

    Robert Wood Johnson Foundation Search How We Work Our Focus Areas About RWJF Search Menu How We ... lives. Learn more For Grantees and Grantseekers The Robert Wood Johnson Foundation supports a wide array of ...

  2. Mechanics of Wood Machining

    CERN Document Server

    Csanády, Etele

    2013-01-01

    Wood is one of the most valuable materials for mankind, and since our earliest days wood materials have been widely used. Today we have modern woodworking machine and tools; however, the raw wood materials available are continuously declining. Therefore we are forced to use this precious material more economically, reducing waste wherever possible. This new textbook on the “Mechanics of Wood Machining” combines the quantitative, mathematical analysis of the mechanisms of wood processing with practical recommendations and solutions. Bringing together materials from many sources, the book contains new theoretical and experimental approaches and offers a clear and systematic overview of the theory of wood cutting, thermal loading in wood-cutting tools, dynamic behaviour of tool and work piece, optimum choice of operational parameters and energy consumption, the wear process of the tools, and the general regularities of wood surface roughness. Diagrams are provided for the quick estimation of various process ...

  3. Mucosal exposure to cockroach extract induces allergic sensitization and allergic airway inflammation

    Directory of Open Access Journals (Sweden)

    Arizmendi Narcy G

    2011-12-01

    Full Text Available Abstract Background Allergic sensitization to aeroallergens develops in response to mucosal exposure to these allergens. Allergic sensitization may lead to the development of asthma, which is characterized by chronic airway inflammation. The objective of this study is to describe in detail a model of mucosal exposure to cockroach allergens in the absence of an exogenous adjuvant. Methods Cockroach extract (CE was administered to mice intranasally (i.n. daily for 5 days, and 5 days later mice were challenged with CE for 4 consecutive days. A second group received CE i.n. for 3 weeks. Airway hyperresponsiveness (AHR was assessed 24 h after the last allergen exposure. Allergic airway inflammation was assessed by BAL and lung histology 48 h after the last allergen exposure. Antigen-specific antibodies were assessed in serum. Lungs were excised from mice from measurement of cytokines and chemokines in whole lung lysate. Results Mucosal exposure of Balb/c mice to cockroach extract induced airway eosinophilic inflammation, AHR and cockroach-specific IgG1; however, AHR to methacholine was absent in the long term group. Lung histology showed patchy, multicentric damage with inflammatory infiltrates at the airways in both groups. Lungs from mice from the short term group showed increased IL-4, CCL11, CXCL1 and CCL2 protein levels. IL4 and CXCL1 were also increased in the BAL of cockroach-sensitized mice in the short-term protocol. Conclusions Mucosal exposure to cockroach extract in the absence of adjuvant induces allergic airway sensitization characterized by AHR, the presence of Th2 cytokines in the lung and eosinophils in the airways.

  4. Ethanolamine iin impregnated wood

    OpenAIRE

    Humar, Miha; Petrič, Marko

    2000-01-01

    Wood preservation is necessary and is economically important. Copper compoundsare used for wood preservation because of their good fungicidal properties. Since copper compounds do not fix into wood, they can leach out ofit. A presence of chromium prevents leaching of copper from wood. Recently, many countries intend to bound or limit the use of chromium salts. Therefore, experts looking for other suitable compounds to fix copper and amines seem to be suitable substitutes for chromium. We repo...

  5. Non_standard Wood

    DEFF Research Database (Denmark)

    Tamke, Martin

    . Using parametric design tools and computer controlled production facilities Copenhagens Centre for IT and Architecture undertook a practice based research into performance based non-standard element design and mass customization techniques. In close cooperation with wood construction software......, but the integration of traditional wood craft techniques. The extensive use of self adjusting, load bearing wood-wood joints contributed to ease in production and assembly of a performance based architecture....

  6. Fire retardants for wood

    Directory of Open Access Journals (Sweden)

    Vlatka Jirouš-Rajković

    2009-06-01

    Full Text Available Along with many advantages, wood as traditional building material also has some disadvantages. One of them is the flammability. The most usual way to improve the fire performance of wood is by treating it with fire retardants that can be applied to wood composite products during manufacture, pressure impregnated into solid wood or wood products or added as a paint or surface coating. Fire retardants are formulated to control ignition, flame spread on the wood surface and to reduce the amount of heat released from wood. Fire retardants cannot make wood non combustible. According to the European reaction-to-fire “Euroclasses”classification system for construction products, wood treated with fire retardant can meet the requirements of Euroclass B, whereas ordinary wood products typically fall into class D. This article attempts to bring together information related to the burning of wood, fire performance of wood, types of fire retardants and mechanism of fire retardancy. Fire retardant coatings and chemical impregnation by pressure-treating are described separately.

  7. Request for wood samples

    NARCIS (Netherlands)

    NN,

    1977-01-01

    In recent years the wood collection at the Rijksherbarium was greatly expanded following a renewed interest in wood anatomy as an aid for solving classification problems. Staff members of the Rijksherbarium added to the collection by taking interesting wood samples with them from their expeditions (

  8. Wood production, wood technology, and biotechnological impacts.

    OpenAIRE

    2007-01-01

    In the year 2001, Prof. Dr. Ursula Kües was appointed at the Faculty of Forest Sciences and Forest Ecology of the Georg-August-University Göttingen to the chair Molecular Wood Biotechnology endowed by the Deutsche Bundesstiftung Umwelt (DBU). Her group studies higher fungi in basic and applied research. Research foci are on mushroom development and on fungal enzymes degrading wood and their applications in wood biotechnology. This book has been edited to thank the DBU for all support given to...

  9. Biocontrol of the Brown-banded Cockroach, Supella longipalpa F. (Blattaria: Blattellidae, with Entomopathogenic Fungus, Metharhizium anisopliae

    Directory of Open Access Journals (Sweden)

    Mona Sharififard

    2016-01-01

    Full Text Available Background: Considering to the high distribution of cockroaches as urban pests, the efficacy of different formula­tions of Metarhizium anisopliae strain Iran 437C were assessed against the brown-banded cockroach, Supella longi­palpa F. under laboratory and field conditions.Methods: Metarhizium anisopliae isolates were screened with immersing adults of the brown-banded cockroachs in aqueous suspension of 108 conidia ml-1 followed by surface or bait treated with different doses of the most virulent isolate against the nymphs. Then formulations of conidia oil-in-water were examined versus cockroach nymphs us­ing different plant oils and paraffin. Then they were evaluated and compared with aqueous suspension and control group. On a large-scale, the sunflower oil-in-water formulation of conidia was sprayed at houses using a hand sprayer.Results: Metarhizium anisopliae IRAN 437C was the most virulent isolate against the brown-banded cockroach, causing 100% mortality in adults at seven days post-exposure. Inoculated bait with this isolate was not enough path­ogenic against the cockroach even at two weeks after treatment. Treated surface with conidia as aqueous suspension or oil-in- water formulation was more effective than the bait formulation against the cockroach caused 39.4–97.2% mortality compared with 2.5% mortality in control group after two days. Spraying the conidia formulated with sun­flower oil was an effective formulation causing 76.1% reduction in the cockroach density on the third day post treatment in the houses.Conclusion: The oil-in-water formulation of M. anisopliae IRAN 437C could be recommended as a promising al­ternative for cockroach control.  

  10. Some Guides to Discovery About Elm Trees, Owls, Cockroaches, Earthworms, Cement and Concrete.

    Science.gov (United States)

    Busch, Phyllis S.

    The introduction emphasizes the need for environmental and conservation education, and advocates an inquiry approach. Outdoor resources available to every school are listed. Detailed suggestions are made for investigating cement and concrete, cockroaches, earthworms, elm trees, and owls. In each case general background information and a list of…

  11. Gut Bacterial Community of the Xylophagous Cockroaches Cryptocercus punctulatus and Parasphaeria boleiriana

    Science.gov (United States)

    Berlanga, Mercedes; Llorens, Carlos; Comas, Jaume; Guerrero, Ricardo

    2016-01-01

    Cryptocercus punctulatus and Parasphaeria boleiriana are two distantly related xylophagous and subsocial cockroaches. Cryptocercus is related to termites. Xylophagous cockroaches and termites are excellent model organisms for studying the symbiotic relationship between the insect and their microbiota. In this study, high-throughput 454 pyrosequencing of 16S rRNA was used to investigate the diversity of metagenomic gut communities of C. punctulatus and P. boleiriana, and thereby to identify possible shifts in symbiont allegiances during cockroaches evolution. Our results revealed that the hindgut prokaryotic communities of both xylophagous cockroaches are dominated by members of four Bacteria phyla: Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. Other identified phyla were Spirochaetes, Planctomycetes, candidatus Saccharibacteria (formerly TM7), and Acidobacteria, each of which represented 1–2% of the total population detected. Community similarity based on phylogenetic relatedness by unweighted UniFrac analyses indicated that the composition of the bacterial community in the two species was significantly different (P host of providing nutrients in appropriate quantities and balance. PMID:27054320

  12. Afro-Asian cockroach from Chiapas amber and the lost Tertiary American entomofauna

    Science.gov (United States)

    Vršanský, Peter; Cifuentes-Ruiz, Paulina; Vidlička, Ľubomír; Čiampor, Fedor; Vega, Francisco J.

    2011-10-01

    Cockroach genera with synanthropic species (Blattella, Ectobius, Supella, Periplaneta, Diploptera and ?Blatta), as well as other insects such as honeybees, although natively limited to certain continents nowadays, had circumtropic distribution in the past. The ease of their reintroduction into their former range suggests a post-Early Miocene environmental stress which led to the extinction of cosmopolitan Tertiary entomofauna in the Americas, whilst in Eurasia, Africa and Australia this fauna survived. This phenomenon is demonstrated here on a low diversity (10 spp.) living cockroach genus Supella, which is peculiar for the circumtropical synanthropic brownbanded cockroach S. longipalpa and also for its exclusively free-living cavicolous species restricted to Africa. S. (Nemosupella) miocenica sp. nov. from the Miocene amber of Chiapas in Mexico is a sister species to the living S. mirabilis from the Lower Guinea forests and adjacent savannas. The difference is restricted to the shape of the central macula on the pronotum, and size, which may indicate the around-Miocene origin of the living, extremely polymorphic Supella species and possibly also the isochronic invasion into the Americas. The species also has a number of characteristics of the Asian (and possibly also Australian) uniform genus Allacta (falling within the generic variability of Supella) suggesting Supella is a direct ancestor of the former. The present species is the first significant evidence for incomplete hiati between well defined cockroach genera — a result of the extensive fossil record of the group. The reported specimen is covered by a mycelium of a parasitic fungus Cordyceps or Entomophthora.

  13. Home Sweet Home: How to Build a Madagascar Hissing Cockroach Habitat out of Recycled Materials

    Science.gov (United States)

    Wagler, Ron

    2010-01-01

    Madagascar hissing cockroaches (MHC) are amazing insects that can be an integral part of an effective science learning and teaching environment. MHCs have a fascinating social structure. They make excellent pets, teach students how to properly care for animals, and their large size adds to their "wow" factor. These characteristics make them unique…

  14. Ecological niche models for four native cockroach species (Blattaria: Blattellidae: Ectobiinae) in the Netherlands

    NARCIS (Netherlands)

    Ciliberti, P.; Jong, de H.; Schouten, M.A.; Verweij, P.A.; Heitmans, W.R.B.

    2009-01-01

    This paper aims at modelling the spatial distribution of the cockroach species Capraiellus panzeri, Ectobius lapponicus, Ectobius pallidus and Ectobius sylvestris within the Netherlands and comparing the habitat preferences of these species. Maxent was used to calculate habitat suitability and to id

  15. Wood decay at sea

    Science.gov (United States)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  16. Anaerobic carbon monoxide dehydrogenase diversity in the homoacetogenic hindgut microbial communities of lower termites and the wood roach.

    Directory of Open Access Journals (Sweden)

    Eric G Matson

    Full Text Available Anaerobic carbon monoxide dehydrogenase (CODH is a key enzyme in the Wood-Ljungdahl (acetyl-CoA pathway for acetogenesis performed by homoacetogenic bacteria. Acetate generated by gut bacteria via the acetyl-CoA pathway provides considerable nutrition to wood-feeding dictyopteran insects making CODH important to the obligate mutualism occurring between termites and their hindgut microbiota. To investigate CODH diversity in insect gut communities, we developed the first degenerate primers designed to amplify cooS genes, which encode the catalytic (β subunit of anaerobic CODH enzyme complexes. These primers target over 68 million combinations of potential forward and reverse cooS primer-binding sequences. We used the primers to identify cooS genes in bacterial isolates from the hindgut of a phylogenetically lower termite and to sample cooS diversity present in a variety of insect hindgut microbial communities including those of three phylogenetically-lower termites, Zootermopsis nevadensis, Reticulitermes hesperus, and Incisitermes minor, a wood-feeding cockroach, Cryptocercus punctulatus, and an omnivorous cockroach, Periplaneta americana. In total, we sequenced and analyzed 151 different cooS genes. These genes encode proteins that group within one of three highly divergent CODH phylogenetic clades. Each insect gut community contained CODH variants from all three of these clades. The patterns of CODH diversity in these communities likely reflect differences in enzyme or physiological function, and suggest that a diversity of microbial species participate in homoacetogenesis in these communities.

  17. Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot.

    Science.gov (United States)

    Jayaram, Kaushik; Full, Robert J

    2016-02-23

    Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300-800 ms by compressing their body 40-60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s(-1), despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion--"body-friction legged crawling" with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces. PMID:26858443

  18. Symbiotic essential amino acids provisioning in the American cockroach, Periplaneta americana (Linnaeus) under various dietary conditions.

    Science.gov (United States)

    Ayayee, Paul A; Larsen, Thomas; Sabree, Zakee

    2016-01-01

    Insect gut microbes have been shown to provide nutrients such as essential amino acids (EAAs) to their hosts. How this symbiotic nutrient provisioning tracks with the host's demand is not well understood. In this study, we investigated microbial essential amino acid (EAA) provisioning in omnivorous American cockroaches (Periplaneta americana), fed low-quality (LQD) and comparatively higher-quality dog food (DF) diets using carbon stable isotope ratios of EAAs (δ (13)CEAA). We assessed non-dietary EAA input, quantified as isotopic offsets (Δ(13)C) between cockroach (δ (13)CCockroach EAA) and dietary (δ (13)CDietary EAA) EAAs, and subsequently determined biosynthetic origins of non-dietary EAAs in cockroaches using (13)C-fingerprinting with dietary and representative bacterial and fungal δ (13)CEAA. Investigation of biosynthetic origins of de novo non-dietary EAAs indicated bacterial origins of EAA in cockroach appendage samples, and a mixture of fungal and bacterial EAA origins in gut filtrate samples for both LQD and DF-fed groups. We attribute the bacteria-derived EAAs in cockroach appendages to provisioning by the fat body residing obligate endosymbiont, Blattabacterium and gut-residing bacteria. The mixed signatures of gut filtrate samples are attributed to the presence of unassimilated dietary, as well as gut microbial (bacterial and fungal) EAAs. This study highlights the potential impacts of dietary quality on symbiotic EAA provisioning and the need for further studies investigating the interplay between host EAA demands, host dietary quality and symbiotic EAA provisioning in response to dietary sufficiency or deficiency. PMID:27231663

  19. Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot.

    Science.gov (United States)

    Jayaram, Kaushik; Full, Robert J

    2016-02-23

    Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300-800 ms by compressing their body 40-60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s(-1), despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion--"body-friction legged crawling" with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces.

  20. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust parame...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  1. Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Astrup, T.; Hansen, K. K.; Hoffmeyer, P.;

    2005-01-01

    Modelling of moisture transport in wood is of great importance as most mechanical and physical properties of wood depend on moisture content. Moisture transport in porous materials is often described by Ficks second law, but several observations indicate that this does not apply very well to wood....... Recently at the Technical University of Denmark, Department of Civil Engineering, a new model for moisture transport in wood has been developed. The model divides the transport into two phases, namely water vapour in the cell lumens and bound water in the cell walls....

  2. The 2010 Broad Prize

    Science.gov (United States)

    Education Digest: Essential Readings Condensed for Quick Review, 2011

    2011-01-01

    A new data analysis, based on data collected as part of The Broad Prize process, provides insights into which large urban school districts in the United States are doing the best job of educating traditionally disadvantaged groups: African-American, Hispanics, and low-income students. Since 2002, The Eli and Edythe Broad Foundation has awarded The…

  3. The Madagascar hissing cockroach as a novel surrogate host for Burkholderia pseudomallei, B. mallei and B. thailandensis

    Directory of Open Access Journals (Sweden)

    Fisher Nathan A

    2012-06-01

    Full Text Available Abstract Background Burkholderia pseudomallei and Burkholderia mallei are gram-negative pathogens responsible for the diseases melioidosis and glanders, respectively. Both species cause disease in humans and animals and have been designated as category B select agents by the Centers for Disease Control and Prevention (CDC. Burkholderia thailandensis is a closely related bacterium that is generally considered avirulent for humans. While it can cause disease in rodents, the B. thailandensis 50% lethal dose (LD50 is typically ≥ 104-fold higher than the B. pseudomallei and B. mallei LD50 in mammalian models of infection. Here we describe an alternative to mammalian hosts in the study of virulence and host-pathogen interactions of these Burkholderia species. Results Madagascar hissing cockroaches (MH cockroaches possess a number of qualities that make them desirable for use as a surrogate host, including ease of breeding, ease of handling, a competent innate immune system, and the ability to survive at 37°C. MH cockroaches were highly susceptible to infection with B. pseudomallei, B. mallei and B. thailandensis and the LD50 was 50 for Escherichia coli in MH cockroaches was >105 cfu. B. pseudomallei, B. mallei, and B. thailandensis cluster 1 type VI secretion system (T6SS-1 mutants were all attenuated in MH cockroaches, which is consistent with previous virulence studies conducted in rodents. B. pseudomallei mutants deficient in the other five T6SS gene clusters, T6SS-2 through T6SS-6, were virulent in both MH cockroaches and hamsters. Hemocytes obtained from MH cockroaches infected with B. pseudomallei harbored numerous intracellular bacteria, suggesting that this facultative intracellular pathogen can survive and replicate inside of MH cockroach phagocytic cells. The hemolymph extracted from these MH cockroaches also contained multinuclear giant cells (MNGCs with intracellular B. pseudomallei, which indicates that infected hemocytes can

  4. Efficacy of imidacloprid and fipronil gels over synthetic pyrethroid and propoxur aerosols in control of German cockroaches (Dictyoptera: Blatellidae

    Directory of Open Access Journals (Sweden)

    V.K. Agrawal

    2010-03-01

    Full Text Available Background & objectives: Resistance amongst cockroaches has been reported to most of the sprayinsecticides apart from the problem of food contamination and inconvenience. Gel baits which canbe selectively applied have been found effective in control of cockroaches in laboratory studies butvery few field studies are available. This trial was planned to evaluate the efficacy of fipronil(0.01% and imidacloprid (2.15% gels over synthetic pyrethroid (0.02% deltamethrin + 0.13%allethrin and propoxur (2% aerosols in control of cockroaches in the field.Methods: Survey was done to find out pre-treatment density in catering establishments and housesby visual count and sticky trap methods. A total of 10 catering establishments and 10 houseshaving high cockroach infestation were selected by sampling (two catering establishments andhouses for each insecticidal treatment and two for control. Propoxur and synthetic pyrethroidaerosols were used for spraying the infested sites once only. Single application of fipronil andimidacloprid gels was used as crack and crevice treatment. Visual count method gave betterindications of cockroach infestation as compared to sticky trap method, hence, the same was followedfor post-treatment evaluation every week up to 12 weeks.Results: Synthetic pyrethroid could not bring about the desired reduction in cockroach infestationin the present study. Single application of fipronil gel was able to reduce cockroach infestation upto 96.8% at the end of 12 weeks whereas imidacloprid application resulted in 90.9% reduction andpropoxur resulted in 77.5%. However, propoxur was more effective in reducing the cockroachdensity by first week in comparison to imidacloprid and fipronil gels but its efficacy started decliningafter 8th week. Difference was found statistically significant by Kruskal-Wallis H-test.Conclusion: The study reports the efficacy of propoxur aerosol, imidacloprid gel and fipronil gelbaits for control of cockroaches.

  5. Toxicity of Pyrethroid and Organophosphorous Insecticides against Two Field Collected Strains of the German Cockroach Blattella germanica (Blattaria: Blattellidae)

    OpenAIRE

    Limoee, Mojtaba; Davari, Behroz; Moosa-Kazemi, Seyed Hassan

    2012-01-01

    Background: The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for pathogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos) against two hospital- collected strains of the German cockroach was investigated. Methods: Topical bioassay methods were carried out for detecting ...

  6. Isolation of Intestinal Parasites of Public Health Importance from Cockroaches (Blattella germanica in Jimma Town, Southwestern Ethiopia

    Directory of Open Access Journals (Sweden)

    Haji Hamu

    2014-01-01

    Full Text Available Cockroaches are claimed to be mechanical transmitters of disease causing microorganisms such as intestinal parasites, bacteria, fungi, and viruses. This study assessed the potential of the German cockroach Blattella germanica in the mechanical transmission of intestinal parasites of public health importance. A total of 2010 cockroaches were collected from 404 households in Jimma Town, southwestern Ethiopia. All the collected cockroaches were identified to species as B. germanica. The contents of their gut and external body parts were examined for the presence of intestinal parasites. Overall, 152 (75.6% of the 210 batches were found to harbor at least one species of human intestinal parasite. Ascaris lumbricoides, Trichuris trichiura, Taenia spp, Strongyloides-like parasite, Entamoeba histolytica/dispar/moshkovski, Giardia duodenalis and Balantidium coli were detected from gut contents. Moreover, parasites were also isolated from the external surface in 22 (10.95% of the batches. There was significant difference in parasite carriage rate of the cockroaches among the study sites (P=0.013. In conclusion, B. germanica was found to harbor intestinal parasites of public health importance. Hence, awareness on the potential role of cockroaches in the mechanical transmission of human intestinal parasites needs to be created. Moreover, further identification of the Strongyloides-like worm is required using molecular diagnostics.

  7. Isolation of Intestinal Parasites of Public Health Importance from Cockroaches (Blattella germanica) in Jimma Town, Southwestern Ethiopia.

    Science.gov (United States)

    Hamu, Haji; Debalke, Serkadis; Zemene, Endalew; Birlie, Belay; Mekonnen, Zeleke; Yewhalaw, Delenasaw

    2014-01-01

    Cockroaches are claimed to be mechanical transmitters of disease causing microorganisms such as intestinal parasites, bacteria, fungi, and viruses. This study assessed the potential of the German cockroach Blattella germanica in the mechanical transmission of intestinal parasites of public health importance. A total of 2010 cockroaches were collected from 404 households in Jimma Town, southwestern Ethiopia. All the collected cockroaches were identified to species as B. germanica. The contents of their gut and external body parts were examined for the presence of intestinal parasites. Overall, 152 (75.6%) of the 210 batches were found to harbor at least one species of human intestinal parasite. Ascaris lumbricoides, Trichuris trichiura, Taenia spp, Strongyloides-like parasite, Entamoeba histolytica/dispar/moshkovski, Giardia duodenalis and Balantidium coli were detected from gut contents. Moreover, parasites were also isolated from the external surface in 22 (10.95%) of the batches. There was significant difference in parasite carriage rate of the cockroaches among the study sites (P = 0.013). In conclusion, B. germanica was found to harbor intestinal parasites of public health importance. Hence, awareness on the potential role of cockroaches in the mechanical transmission of human intestinal parasites needs to be created. Moreover, further identification of the Strongyloides-like worm is required using molecular diagnostics. PMID:24649356

  8. Method of stabilizing wood

    International Nuclear Information System (INIS)

    Wood is impregnated with a mixture of a vinyl or an allyl monomer (20 - 90 wt. %) and unsaturated polyester resins. The impregnated wood is then exposed to ionizing radiation at doses of 0.1 to 20 Mrad at a temperature of 60 to 180 degC. (B.S.)

  9. Mineralization of fossil wood

    NARCIS (Netherlands)

    Buurman, P.

    1972-01-01

    Several pieces of fossil wood have been analyzed with X-ray diffraction and were grouped on the basis of mineralogical composition. Various mineralizations were studied in thin sections and by means of the scanning electron microscope. Wood-opals appear to show a structure preservation that points t

  10. Ovicidal activity of chitin synthesis inhibitors when fed to adult German cockroaches (Dictyoptera: Blattellidae).

    Science.gov (United States)

    DeMark, J J; Bennett, G W

    1990-07-01

    Ovicidal activity was observed in four adult groups (virgin males; virgin females; newly gravid females; and inseminated, reproducing females) of the German cockroach, Blattella germanica (L.), fed the chitin synthesis inhibitors triflumuron, chlorfluazuron, hexafluron, and UC 84572 (structure not disclosed) at the LC50's and LC95's determined from fifth-stage nymphs. All compounds were active only when fed to reproducing females (including the feeding period in which the ootheca is developing). Hexafluron and triflumuron at the LC50 caused 100% inhibition of hatch in reproducing females. Chlorfluazuron and UC 84572 at the LC50 had similar ovicidal activity (45.8 and 50.0% hatch, respectively). Female German cockroaches fed the chitin synthesis inhibitors before mating and after the ootheca had protruded from the abdomen were not affected. Reproductive capabilities of males were not affected, and males did not effectively transfer the compounds to untreated females during mating. PMID:2388230

  11. Nonlinear signal transmission between second- and third-order neurons of cockroach ocelli

    OpenAIRE

    1990-01-01

    Transfer characteristics of the synapse made from second- to third- order neurons of cockroach ocelli were studied using simultaneous microelectrode penetrations and the application of tetrodotoxin. Potential changes were evoked in second-order neurons by either an extrinsic current or a sinusoidally modulated light. The synapse had a low-pass filter characteristic with a cutoff frequency of 25-30 Hz, which passed most presynaptic signals. The synapse operated at an exponentially rising part ...

  12. De Novo Transcriptome Analysis and Detection of Antimicrobial Peptides of the American Cockroach Periplaneta americana (Linnaeus.

    Directory of Open Access Journals (Sweden)

    In-Woo Kim

    Full Text Available Cockroaches are surrogate hosts for microbes that cause many human diseases. In spite of their generally destructive nature, cockroaches have recently been found to harbor potentially beneficial and medically useful substances such as drugs and allergens. However, genomic information for the American cockroach (Periplaneta americana is currently unavailable; therefore, transcriptome and gene expression profiling is needed as an important resource to better understand the fundamental biological mechanisms of this species, which would be particularly useful for the selection of novel antimicrobial peptides. Thus, we performed de novo transcriptome analysis of P. americana that were or were not immunized with Escherichia coli. Using an Illumina HiSeq sequencer, we generated a total of 9.5 Gb of sequences, which were assembled into 85,984 contigs and functionally annotated using Basic Local Alignment Search Tool (BLAST, Gene Ontology (GO, and Kyoto Encyclopedia of Genes and Genomes (KEGG database terms. Finally, using an in silico antimicrobial peptide prediction method, 86 antimicrobial peptide candidates were predicted from the transcriptome, and 21 of these peptides were experimentally validated for their antimicrobial activity against yeast and gram positive and -negative bacteria by a radial diffusion assay. Notably, 11 peptides showed strong antimicrobial activities against these organisms and displayed little or no cytotoxic effects in the hemolysis and cell viability assay. This work provides prerequisite baseline data for the identification and development of novel antimicrobial peptides, which is expected to provide a better understanding of the phenomenon of innate immunity in similar species.

  13. Composition of the Cockroach Gut Microbiome in the Presence of Parasitic Nematodes

    Science.gov (United States)

    Vicente, Cláudia S. L.; Ozawa, Sota; Hasegawa, Koichi

    2016-01-01

    Cockroaches are parasitized by thelastomatid nematodes, which live in an obligate manner in their hindgut and interact with the resident microbial community. In the present study, a composition analysis was performed on the gut microbiome of Periplaneta fuliginosa and P. americana to investigate natural and artificial infection by thelastomatid nematodes. Nine libraries of the 16S rRNA gene V3–V4 region were prepared for pyrosequencing. We examined the complete gut microbiome (fore-, mid-, and hindgut) of lab-reared P. fuliginosa naturally infected with the parasitic nematode Leidynema appendiculatum and those that were nematode-free, and complemented our study by characterizing the hindgut microbial communities of lab-reared P. americana naturally infected with Hammerschmidtiella diesingi and Thelastoma bulhoesi, artificially infected with L. appendiculatum, and those that were nematode-free. Our results revealed that the fore- and midgut of naturally infected and nematode-free P. fuliginosa have close microbial communities, which is in contrast with hindgut communities; the hindgut communities of both cockroaches exhibit higher microbial diversities in the presence of their natural parasites and marked differences were observed in the abundance of the most representative taxa, namely Firmicutes, Proteobacteria, and Bacteroidetes. Our results have provided basic information and encourage further studies on multitrophic interactions in the cockroach gut as well as the thelastomatid nematodes that play a role in this environment. PMID:27524304

  14. Comparison of two bioassay methods for determining deltamethrin resistance in German cockroaches (Blattodea: Blattellidae).

    Science.gov (United States)

    Choo, L E; Tang, C S; Pang, F Y; Ho, S H

    2000-06-01

    Susceptibility to deltamethrin of 10 strains of the German cockroach, Blattella germanica (L.), trapped in hotel kitchens in Singapore was determined. Two resistance detection bioassay methods (topical application and World Health Organization glass jar method) were compared. Resistance ratios based on 50% knockdown, obtained by comparison with the S strain, ranged from 17.7 to 4,235 for topical application and from 2.2 to 22 for the glass jar method. A field strain, with consistently low resistance ratios (topical method = 17.7, glass jar method = 2.2), was identified as a potential field strain to be used as a baseline for comparison with other field strains. Resistance ratios for the other field strains obtained by comparison with the R5 strain ranged from 24.5 to 239 for topical application and from 1.2 to 9.8 for the glass jar method. The results of our study demonstrate that deltamethrin-resistant German cockroaches are numerous in Singapore. Comparison between the two bioassay methods showed that there was significant correlation between KD50 and KT50 values. The glass jar method is similar to field situations but topical application is sensitive enough to define the magnitude of resistance. Differences between the two detection bioassays and the factors governing the choice of bioassay in monitoring resistance in German cockroaches are discussed. PMID:10902348

  15. De Novo Transcriptome Analysis and Detection of Antimicrobial Peptides of the American Cockroach Periplaneta americana (Linnaeus).

    Science.gov (United States)

    Kim, In-Woo; Lee, Joon Ha; Subramaniyam, Sathiyamoorthy; Yun, Eun-Young; Kim, Iksoo; Park, Junhyung; Hwang, Jae Sam

    2016-01-01

    Cockroaches are surrogate hosts for microbes that cause many human diseases. In spite of their generally destructive nature, cockroaches have recently been found to harbor potentially beneficial and medically useful substances such as drugs and allergens. However, genomic information for the American cockroach (Periplaneta americana) is currently unavailable; therefore, transcriptome and gene expression profiling is needed as an important resource to better understand the fundamental biological mechanisms of this species, which would be particularly useful for the selection of novel antimicrobial peptides. Thus, we performed de novo transcriptome analysis of P. americana that were or were not immunized with Escherichia coli. Using an Illumina HiSeq sequencer, we generated a total of 9.5 Gb of sequences, which were assembled into 85,984 contigs and functionally annotated using Basic Local Alignment Search Tool (BLAST), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) database terms. Finally, using an in silico antimicrobial peptide prediction method, 86 antimicrobial peptide candidates were predicted from the transcriptome, and 21 of these peptides were experimentally validated for their antimicrobial activity against yeast and gram positive and -negative bacteria by a radial diffusion assay. Notably, 11 peptides showed strong antimicrobial activities against these organisms and displayed little or no cytotoxic effects in the hemolysis and cell viability assay. This work provides prerequisite baseline data for the identification and development of novel antimicrobial peptides, which is expected to provide a better understanding of the phenomenon of innate immunity in similar species. PMID:27167617

  16. New predatory cockroaches (Insecta: Blattaria: Manipulatoridae fam.n.) from the Upper Cretaceous Myanmar amber

    Science.gov (United States)

    Vršanský, Peter; Bechly, Günter

    2015-04-01

    We describe a new extinct lineage Manipulatoridae (new family) of cockroaches from the Upper Cretaceous (Cenomanian) amber of Myanmar. Manipulator modificaputis gen. et sp. n. is a morphologically unique extinct cockroach that represents the first (of a total of 29 known worldwide) cockroach family reported exclusively from the Myanmar amber. This family represents an early side branch of the stem group of Mantodea (most probably a sister group of Eadiidae within Blattaria/Corydioidea) because it has some synapomorphies with the Mantodea (including the stem group and Eadiidae). This family also retains symplesiomorphies that exclude a position in the crown group, and furthermore has unique autapomorphies that exclude a position as a direct ancestor of Mantodea. The unique adaptations such as strongly elongated extremities and freely movable head on a long neck suggest that these animals were pursuit predators. Five additional specimens (including two immatures) reported from the Myanmar amber suggest that this group was relatively rare but belonged to the indigenous and autochthonous inhabitants of the ancient amber forest of the Myanmar region.

  17. Lack of repellency of three commercial ultrasonic devices to the German cockroach (Blattodea: Blattellidae)

    Institute of Scientific and Technical Information of China (English)

    FANGNENG HUANG; BHADRIRAJU SUBRAMANYAM

    2006-01-01

    Three commercial ultrasonic devices (A, B, and C) were tested for their ability to repel the German cockroach, Blattella germanica (L.) (Blattodea: Blattellidae), in Plexiglas(R) enclosures. Device A generated peak frequencies at 26 kHz and 34 kHz, and produced a 95 ± 1 dB sound pressure level (SPL) at 50 cm distance (0 dB = 20 log10[20 μPa/20μPa]). Device B generated peak frequencies at 27 kHz and 35 kHz, and produced a 92 ±4 dB SPL. Device C generated a wide range of frequencies between 28-42 kHz and produced an 88 ± 2 dB SPL. Ultrasound from any of the three devices did not demonstrate sufficient repelling ability against the German cockroach in the tests. The result failed to provide evidence that ultrasonic technology could be used as an effective pest management tool to repel or eliminate the German cockroach.

  18. Computational optimization for S-type biological systems: cockroach genetic algorithm.

    Science.gov (United States)

    Wu, Shinq-Jen; Wu, Cheng-Tao

    2013-10-01

    S-type biological systems (S-systems) are demonstrated to be universal approximations of continuous biological systems. S-systems are easy to be generalized to large systems. The systems are identified through data-driven identification techniques (cluster-based algorithms or computational methods). However, S-systems' identification is challenging because multiple attractors exist in such highly nonlinear systems. Moreover, in some biological systems the interactive effect cannot be neglected even the interaction order is small. Therefore, learning should be focused on increasing the gap between the true and redundant interaction. In addition, a wide searching space is necessary because no prior information is provided. The used technologies should have the ability to achieve convergence enhancement and diversity preservation. Cockroaches live in nearly all habitats and survive for more than 300 million years. In this paper, we mimic cockroaches' competitive swarm behavior and integrated it with advanced evolutionary operations. The proposed cockroach genetic algorithm (CGA) possesses strong snatching-food ability to rush forward to a target and high migration ability to escape from local minimum. CGA was tested with three small-scale systems, a twenty-state medium-scale system and a thirty-state large-scale system. A wide search space ([0,100] for rate constants and [-100,100] for kinetic orders) with random or bad initial starts are used to show the high exploration performance.

  19. Evolutionary convergence and nitrogen metabolism in Blattabacterium strain Bge, primary endosymbiont of the cockroach Blattella germanica.

    Science.gov (United States)

    López-Sánchez, Maria J; Neef, Alexander; Peretó, Juli; Patiño-Navarrete, Rafael; Pignatelli, Miguel; Latorre, Amparo; Moya, Andrés

    2009-11-01

    Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state.

  20. De Novo Transcriptome Analysis and Detection of Antimicrobial Peptides of the American Cockroach Periplaneta americana (Linnaeus).

    Science.gov (United States)

    Kim, In-Woo; Lee, Joon Ha; Subramaniyam, Sathiyamoorthy; Yun, Eun-Young; Kim, Iksoo; Park, Junhyung; Hwang, Jae Sam

    2016-01-01

    Cockroaches are surrogate hosts for microbes that cause many human diseases. In spite of their generally destructive nature, cockroaches have recently been found to harbor potentially beneficial and medically useful substances such as drugs and allergens. However, genomic information for the American cockroach (Periplaneta americana) is currently unavailable; therefore, transcriptome and gene expression profiling is needed as an important resource to better understand the fundamental biological mechanisms of this species, which would be particularly useful for the selection of novel antimicrobial peptides. Thus, we performed de novo transcriptome analysis of P. americana that were or were not immunized with Escherichia coli. Using an Illumina HiSeq sequencer, we generated a total of 9.5 Gb of sequences, which were assembled into 85,984 contigs and functionally annotated using Basic Local Alignment Search Tool (BLAST), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) database terms. Finally, using an in silico antimicrobial peptide prediction method, 86 antimicrobial peptide candidates were predicted from the transcriptome, and 21 of these peptides were experimentally validated for their antimicrobial activity against yeast and gram positive and -negative bacteria by a radial diffusion assay. Notably, 11 peptides showed strong antimicrobial activities against these organisms and displayed little or no cytotoxic effects in the hemolysis and cell viability assay. This work provides prerequisite baseline data for the identification and development of novel antimicrobial peptides, which is expected to provide a better understanding of the phenomenon of innate immunity in similar species.

  1. Analysis of Cockroach Fauna and Frequency in Human Residential Habitats of North of Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Dehghani R.1 PhD,

    2016-08-01

    Full Text Available Aims Considering the medical significance of cockroaches as insect vectors of food toxicities, and triggering allergy in respiratory system and skin, this survey was conducted to study the frequency of infestation and their effective factors in Shahin Shahr, Iran. Materials & Methods This cross-sectional descriptive study was carried out in 2010 in Shahin Shahr, Isfahan, Iran. Data gathering instrument was a researcher-made questionnaire regarding to the research aims. Data were analyzed by SPSS 11.5 software using Chi square and Fisher exact tests. Findings 675 of 1000 studied houses (67.5% were infested by all life stages of the cockroaches and 32.5% had no infestation. 46% of infested houses had few, 30% had medium and 24% had high infestation. the bathrooms and toilets were recognized as the most infested places (41%. There were significant relationships between infestation of houses and the age of building (p<0.001, the type of building (p=0.009 and the education level of the family (p<0.001. Significant difference was found between houses equipped their doors and windows by tulles and without tulles (p=0.03. Most infection was found in houses sheltering 5 and more people (72.3%. Significant correlation was found between the infection and the number of family members (p=0.0012. Conclusion Infestation rate of cockroaches in Shahin Shahr houses is high and is mostly of P. americana species.

  2. Composition of the Cockroach Gut Microbiome in the Presence of Parasitic Nematodes.

    Science.gov (United States)

    Vicente, Cláudia S L; Ozawa, Sota; Hasegawa, Koichi

    2016-09-29

    Cockroaches are parasitized by thelastomatid nematodes, which live in an obligate manner in their hindgut and interact with the resident microbial community. In the present study, a composition analysis was performed on the gut microbiome of Periplaneta fuliginosa and P. americana to investigate natural and artificial infection by thelastomatid nematodes. Nine libraries of the 16S rRNA gene V3-V4 region were prepared for pyrosequencing. We examined the complete gut microbiome (fore-, mid-, and hindgut) of lab-reared P. fuliginosa naturally infected with the parasitic nematode Leidynema appendiculatum and those that were nematode-free, and complemented our study by characterizing the hindgut microbial communities of lab-reared P. americana naturally infected with Hammerschmidtiella diesingi and Thelastoma bulhoesi, artificially infected with L. appendiculatum, and those that were nematode-free. Our results revealed that the fore- and midgut of naturally infected and nematode-free P. fuliginosa have close microbial communities, which is in contrast with hindgut communities; the hindgut communities of both cockroaches exhibit higher microbial diversities in the presence of their natural parasites and marked differences were observed in the abundance of the most representative taxa, namely Firmicutes, Proteobacteria, and Bacteroidetes. Our results have provided basic information and encourage further studies on multitrophic interactions in the cockroach gut as well as the thelastomatid nematodes that play a role in this environment. PMID:27524304

  3. Cord Wood Testing in a Non-Catalytic Wood Stove

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trojanowski, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wei, G. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-06-30

    EPA Method 28 and the current wood stove regulations have been in-place since 1988. Recently, EPA proposed an update to the existing NSPS for wood stove regulations which includes a plan to transition from the current crib wood fuel to cord wood fuel for certification testing. Cord wood is seen as generally more representative of field conditions while the crib wood is seen as more repeatable. In any change of certification test fuel, there are questions about the impact on measured results and the correlation between tests with the two different fuels. The purpose of the work reported here is to provide data on the performance of a noncatalytic stove with cord wood. The stove selected has previously been certified with crib wood which provides a basis for comparison with cord wood. Overall, particulate emissions were found to be considerably higher with cord wood.

  4. Fatigue Damage in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben;

    1996-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Fatigue failure is found to depend both on the total time under load and on the number of cycles.Recent accelerated fatigue research on wood is reviewed, and a discrepancy between...... to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation between stiffness reduction...

  5. A wasp manipulates neuronal activity in the sub-esophageal ganglion to decrease the drive for walking in its cockroach prey.

    Directory of Open Access Journals (Sweden)

    Ram Gal

    Full Text Available BACKGROUND: The parasitoid Jewel Wasp hunts cockroaches to serve as a live food supply for its offspring. The wasp stings the cockroach in the head and delivers a cocktail of neurotoxins directly inside the prey's cerebral ganglia. Although not paralyzed, the stung cockroach becomes a living yet docile 'zombie', incapable of self-initiating spontaneous or evoked walking. We show here that such neuro-chemical manipulation can be attributed to decreased neuronal activity in a small region of the cockroach cerebral nervous system, the sub-esophageal ganglion (SEG. A decrease in descending permissive inputs from this ganglion to thoracic central pattern generators decreases the propensity for walking-related behaviors. METHODOLOGY AND PRINCIPAL FINDINGS: We have used behavioral, neuro-pharmacological and electrophysiological methods to show that: (1 Surgically removing the cockroach SEG prior to wasp stinging prolongs the duration of the sting 5-fold, suggesting that the wasp actively targets the SEG during the stinging sequence; (2 injecting a sodium channel blocker, procaine, into the SEG of non-stung cockroaches reversibly decreases spontaneous and evoked walking, suggesting that the SEG plays an important role in the up-regulation of locomotion; (3 artificial focal injection of crude milked venom into the SEG of non-stung cockroaches decreases spontaneous and evoked walking, as seen with naturally-stung cockroaches; and (4 spontaneous and evoked neuronal spiking activity in the SEG, recorded with an extracellular bipolar microelectrode, is markedly decreased in stung cockroaches versus non-stung controls. CONCLUSIONS AND SIGNIFICANCE: We have identified the neuronal substrate responsible for the venom-induced manipulation of the cockroach's drive for walking. Our data strongly support previous findings suggesting a critical and permissive role for the SEG in the regulation of locomotion in insects. By injecting a venom cocktail directly into the

  6. Edge Glued Wood Panel Technology and an Assessment on the Development of Edge Glued Wood Panel Industry

    Directory of Open Access Journals (Sweden)

    Tuncer Dilik

    2012-01-01

    Full Text Available In this research, it is aimed to determine the general situation of edge glued wood panel industry that is rapidly developing in Turkey with the reasons of this development similar to the development edge glued wood panel industry in the world. Besides, starting from its definition, there are information about edge glued wood panel, comparison with other panel products and technology preferences of production. As the result of this study, there are 3 essential reasons of the rapid development of edge glued wood panel industry in Turkey. These are; (1 Environmental health and ecological approaches as a movement of thought having impact on the consumer behaviors and rapidly improving throughout the world, (2 Having less production and investment cost compared to the other wood based material production and investments and (3 In addition to the advantages owned when compared to the other wood based materials, having the production technology involving flexible production systems to respond to every demand level. According to the data related to edge glued wood panel demand and supplies, the production of edge glued wood panels replace to East Europe where there is also Turkey. It is determined that investment and cost of Turkish edge glued wood panel are mainly in Marmara region (43.3% and raw material (43% respectively. 67% coniferous and 33% broad leaved tree species are used in Turkish edge glued wood panel production. The most preferred edge glued wood panel thicknesses are 16, 19, 30 and 42 mm. The technological preferences of the manufacturers depend on their machines and production line with optimization systems where as the users’ preferences are price and quality by 90%. It is determined that with its structural condition, the sector is open for investment and development.

  7. Wood pellet research program

    Energy Technology Data Exchange (ETDEWEB)

    Sohkansanj, S.; Bi, T. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering

    2006-07-01

    Wood pellets are composed of waste wood materials such as sawmill residue, municipal landfill waste and grain crops. Due to the high temperature combustion used to form the waste materials into the pellet, no additives or glues are necessary to bind them. The pellets are typically used for home heating; heat and power production; poultry bedding; and in biorefineries. This presentation provided an outline of the University of British Columbia wood pellet research and development program. Research at the university is being conducted to develop new types of pellets. Researchers at the program also analyze the physical and chemical properties of pellets in order to optimize pellet density and heating values. Wood pellet modelling and simulation studies are carried out, and various training and education programs are also offered. Research is currently being conducted to develop a reactor for off-gassing experiments. This presentation also provided details of a study investigating the economics of wood pellet production and transport. Pellet production costs and feedstock costs were compared. A summary of the costs and energy inputs of pellet production included details of product storage; transportation and transfer; handling; and transportation to energy plants. It was concluded that more than 35 per cent of the energy content of biomass is used up in the processing and transport of Canadian wood pellets to Europe. refs., tabs., figs.

  8. Wood pellet research program

    International Nuclear Information System (INIS)

    Wood pellets are composed of waste wood materials such as sawmill residue, municipal landfill waste and grain crops. Due to the high temperature combustion used to form the waste materials into the pellet, no additives or glues are necessary to bind them. The pellets are typically used for home heating; heat and power production; poultry bedding; and in biorefineries. This presentation provided an outline of the University of British Columbia wood pellet research and development program. Research at the university is being conducted to develop new types of pellets. Researchers at the program also analyze the physical and chemical properties of pellets in order to optimize pellet density and heating values. Wood pellet modelling and simulation studies are carried out, and various training and education programs are also offered. Research is currently being conducted to develop a reactor for off-gassing experiments. This presentation also provided details of a study investigating the economics of wood pellet production and transport. Pellet production costs and feedstock costs were compared. A summary of the costs and energy inputs of pellet production included details of product storage; transportation and transfer; handling; and transportation to energy plants. It was concluded that more than 35 per cent of the energy content of biomass is used up in the processing and transport of Canadian wood pellets to Europe. refs., tabs., figs

  9. Brain-Computer Interface Controlled Cyborg: Establishing a Functional Information Transfer Pathway from Human Brain to Cockroach Brain

    Science.gov (United States)

    2016-01-01

    An all-chain-wireless brain-to-brain system (BTBS), which enabled motion control of a cyborg cockroach via human brain, was developed in this work. Steady-state visual evoked potential (SSVEP) based brain-computer interface (BCI) was used in this system for recognizing human motion intention and an optimization algorithm was proposed in SSVEP to improve online performance of the BCI. The cyborg cockroach was developed by surgically integrating a portable microstimulator that could generate invasive electrical nerve stimulation. Through Bluetooth communication, specific electrical pulse trains could be triggered from the microstimulator by BCI commands and were sent through the antenna nerve to stimulate the brain of cockroach. Serial experiments were designed and conducted to test overall performance of the BTBS with six human subjects and three cockroaches. The experimental results showed that the online classification accuracy of three-mode BCI increased from 72.86% to 78.56% by 5.70% using the optimization algorithm and the mean response accuracy of the cyborgs using this system reached 89.5%. Moreover, the results also showed that the cyborg could be navigated by the human brain to complete walking along an S-shape track with the success rate of about 20%, suggesting the proposed BTBS established a feasible functional information transfer pathway from the human brain to the cockroach brain. PMID:26982717

  10. Brain-Computer Interface Controlled Cyborg: Establishing a Functional Information Transfer Pathway from Human Brain to Cockroach Brain.

    Science.gov (United States)

    Li, Guangye; Zhang, Dingguo

    2016-01-01

    An all-chain-wireless brain-to-brain system (BTBS), which enabled motion control of a cyborg cockroach via human brain, was developed in this work. Steady-state visual evoked potential (SSVEP) based brain-computer interface (BCI) was used in this system for recognizing human motion intention and an optimization algorithm was proposed in SSVEP to improve online performance of the BCI. The cyborg cockroach was developed by surgically integrating a portable microstimulator that could generate invasive electrical nerve stimulation. Through Bluetooth communication, specific electrical pulse trains could be triggered from the microstimulator by BCI commands and were sent through the antenna nerve to stimulate the brain of cockroach. Serial experiments were designed and conducted to test overall performance of the BTBS with six human subjects and three cockroaches. The experimental results showed that the online classification accuracy of three-mode BCI increased from 72.86% to 78.56% by 5.70% using the optimization algorithm and the mean response accuracy of the cyborgs using this system reached 89.5%. Moreover, the results also showed that the cyborg could be navigated by the human brain to complete walking along an S-shape track with the success rate of about 20%, suggesting the proposed BTBS established a feasible functional information transfer pathway from the human brain to the cockroach brain. PMID:26982717

  11. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  12. Derived, still living cockroach genus Cariblattoides (Blattida: Blattellidae) from the Eocene sediments of Green River in Colorado, USA

    Institute of Scientific and Technical Information of China (English)

    Peter Vr(s)ansk(y); Lubomir Vidli(c)ka; Fedor (C)iampor Jr; Finnegan Marsh

    2012-01-01

    Cariblattoides labandeirai sp.n.from the Eocene sediments of Green River in Colorado,USA bear only two plesiomorphies,but also several significant autapomorphies within the advanced and highly derived living cockroach genus.Thus,Cariblattoides with extant occurrence in the Caribbean and South America was historically common in the Nearctic,and represents important evidence for the occurrence of derived living genera of cockroaches ~50 Ma ago.Generally,the vast majority of living genera were absent during the Palaeocene,thus the diversification of most living cockroach lineages near the Palaeocene/Eocene boundary must have been extremely rapid.Females of living C.suave,the type species,have identical (sophisticated) coloration of pronotum,but the most related living taxa are C.piraiensis and C.fontesi from Brazil (supported by phylogenetical analysis).

  13. Fabrication and Spectral Properties of Wood-Based Luminescent Nanocomposites

    Directory of Open Access Journals (Sweden)

    Xianjun Li

    2014-01-01

    Full Text Available Pressure impregnation pretreatment is a conventional method to fabricate wood-based nanocomposites. In this paper, the wood-based luminescent nanocomposites were fabricated with the method and its spectral properties were investigated. The results show that it is feasible to fabricate wood-based luminescent nanocomposites using microwave modified wood and nanophosphor powders. The luminescent strength is in positive correlation with the amount of phosphor powders dispersed in urea-formaldehyde resin. Phosphors absorb UV and blue light efficiently in the range of 400–470 nm and show a broad band of bluish-green emission centered at 500 nm, which makes them good candidates for potential blue-green luminescent materials.

  14. Nervous System of Periplaneta americana Cockroach as a Model in Toxinological Studies: A Short Historical and Actual View.

    Science.gov (United States)

    Stankiewicz, Maria; Dąbrowski, Marcin; de Lima, Maria Elena

    2012-01-01

    Nervous system of Periplaneta americana cockroach is used in a wide range of pharmacological studies, including electrophysiological techniques. This paper presents its role as a preparation in the development of toxinological studies in the following electrophysiological methods: double-oil-gap technique on isolated giant axon, patch-clamp on DUM (dorsal unpaired median) neurons, microelectrode technique in situ conditions on axon in connective and DUM neurons in ganglion, and single-fiber oil-gap technique on last abdominal ganglion synapse. At the end the application of cockroach synaptosomal preparation is mentioned. PMID:22666245

  15. Nervous System of Periplaneta americana Cockroach as a Model in Toxinological Studies: A Short Historical and Actual View

    Directory of Open Access Journals (Sweden)

    Maria Stankiewicz

    2012-01-01

    Full Text Available Nervous system of Periplaneta americana cockroach is used in a wide range of pharmacological studies, including electrophysiological techniques. This paper presents its role as a preparation in the development of toxinological studies in the following electrophysiological methods: double-oil-gap technique on isolated giant axon, patch-clamp on DUM (dorsal unpaired median neurons, microelectrode technique in situ conditions on axon in connective and DUM neurons in ganglion, and single-fiber oil-gap technique on last abdominal ganglion synapse. At the end the application of cockroach synaptosomal preparation is mentioned.

  16. Photodegradation of thermally modified wood.

    Science.gov (United States)

    Srinivas, Kavyashree; Pandey, Krishna K

    2012-12-01

    Natural wood, being biological material, undergoes rapid degradation by ultraviolet (UV) radiations and other environmental factors under outdoor exposure. In order to protect wood from such degradation, the chemical structure of wood is altered by chemical modification or heat treatment. In the present study, heat treated specimens of rubberwood (Hevea brasiliensis) were exposed to xenon light source in a weather-o-meter for different periods up to 300 h. Photostability of modified and unmodified wood was evaluated in terms of colour and chemical changes. Light coloured untreated wood became dark upon UV irradiation whereas, dark colour of heat treated wood lightened on UV exposure. CIE lightness parameter (L(*)) decreased for untreated wood whereas its value increased for heat treated wood upon irradiation. Other colour coordinates a(*) and b(*) increased with exposure duration for both untreated and heat treated wood. The overall colour change (ΔE(*)) increased for both untreated and heat treated wood. The Fourier Transform Infrared (FTIR) spectroscopic studies revealed severe lignin degradation of heat treated wood due to UV light exposure. Colour changes and FTIR measurements indicate that thermal modification of wood was ineffective in restricting light induced colour changes and photodegradation of wood polymers.

  17. Evolutionary convergence and nitrogen metabolism in Blattabacterium strain Bge, primary endosymbiont of the cockroach Blattella germanica.

    Science.gov (United States)

    López-Sánchez, Maria J; Neef, Alexander; Peretó, Juli; Patiño-Navarrete, Rafael; Pignatelli, Miguel; Latorre, Amparo; Moya, Andrés

    2009-11-01

    Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state. PMID:19911043

  18. Comparative study of specific IgE for cockroach between asthma and allergic rhinitis patients

    International Nuclear Information System (INIS)

    To compare the degrees of allergic reaction and the cross-reactive allergens for three strains of cockroach (Periplanceta fuliginosa , Periplaneta americana and Blattella germanica) between patients with asthma and allergic rhinitis, the specific IgE(sIgE) in asthma and allergic rhinitis for these three strains of cockroach were determined with ELISA. The results showed that the sIgE positive rates for Periplaneta americana, Periplaneta fuliginosa and Blattella germanica in patients with asthma were 23.5%, 16.0% and 14.8%, respectively. The reactive coincidence rate between Periplaneta americana and Periplaneta fuliginoas was 74.0%, between Periplaneta americana and Blattella germanica was 73.5%, and between Periplaneta fuliginosa and Blattella germanica was 85.0% in asthma patients. The IgE positive rates for Periplaneta americana, Periplaneta fuliginosa and Blattella gerraanica in allergic rhinitis patients were 24.8%, 17.6% and 15.8%, respectively. The reactive coincidence rate between Periplaneta americana and Periplaneta fuliginosa was 73.9%, between Periplaneta americana and Blattella germanica was 75.2%, and between Periplaneta fuliginosa and Blattella germanica was 86.1% in allergic rhinitis patients. There was no significant difference between asthma and allergic rhinitis patients although the sIgE positive rates of allergic rhinitis patients were higher than those of asthma patients for these three strains of cock- roach. All these results indicated that the degrees of allergic reaction are similar between asthma and allergic rhinitis patients and there are some cross-reactive allergic components among these three strains of cockroach. (authors)

  19. Evolutionary convergence and nitrogen metabolism in Blattabacterium strain Bge, primary endosymbiont of the cockroach Blattella germanica.

    Directory of Open Access Journals (Sweden)

    Maria J López-Sánchez

    2009-11-01

    Full Text Available Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state.

  20. Methane from wood

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S

    2005-07-15

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  1. Methane from wood

    International Nuclear Information System (INIS)

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  2. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben;

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation...

  3. Energetic Cost of Subacute Chlorpyrifos Intoxication in the German Cockroach (Dictyoptera: Blattellidae)

    DEFF Research Database (Denmark)

    Nielsen, Søren Achim; Jensen, Karl-Martin Vagn; Kristensen, Michael;

    2006-01-01

    The energetic cost of a sublethal treatment with chlorpyrifos was estimated by use of direct microcalorimetry to measure metabolic heat in susceptible and resistant strains of the German cockroach Blattella germanica L. Moreover, one of the detoxifcation enzyme systems known to be involved...... production increased in the susceptible strain ...  30 min after exposure and declined again after ... 120 min to the basal level. The energetic cost of the exposure to the insecticide corresponds ... 5 h of normal metabolism. There were no signifcant differences in heat production after toxic treatment...

  4. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  5. False "highlighting" with Wood's lamp.

    Science.gov (United States)

    Silverberg, Jonathan I; Silverberg, Nanette B

    2014-01-01

    Wood's lamp evaluation is used to diagnose pigmentary disorders. For example, vitiligo typically demonstrates lesional enhancement under Wood's lamp evaluation. Numerous false positive enhancing lesions can be noted in the skin. We describe a 5-year-old Hispanic boy who had painted his face with highlighter, producing enhancing lesions under Wood's lamp. Physicians who use Wood's lamp should be aware that the appearance of markers and highlighter can mimic that of true clinical illnesses.

  6. Status of wood energy applications

    International Nuclear Information System (INIS)

    In this address, the potential of wood and wood residues to supply future energy needs is examined. In addition, the possible environmental impact of the use of wood fuels on global climate change is discussed. Technologies for the development of new fuels are described

  7. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Matos, O.; Ribeiro, R. [Biomass Centre for Energy - CBE, Miranda do Corvo (Portugal)

    1997-12-31

    The energy policy of the EC, as well as most of member states points to a sizeable increase of energy production based on renewable energy sources, wood, wood residues, agricultural residues, energy crops including SRF, organic sludges, solid residues, etc. Most recent goals indicate a desirable duplication of today`s percentage by 2010. The reasons for this interest, besides diversification of sources, less dependence on imported fuels, use of endogenous resources, expected decrease of fossil fuel reserves, use of available land, additional employment and income for rural communities, etc., are related to important environmental benefits namely in terms of emissions of hot house gases. Wood waste, resulting from forest operations, cleaning, cultural and final cuttings, and from wood based industries, constitute a special important resource by reason of quality and availability. In addition to this they do not require additional land use and the removal is beneficial. In the run-up to the becoming December`s 1997 `Climate Change Summit` in Kioto, there is mounting pressure on companies to plan on carbon cuts. (author) 6 refs., 1 tab.

  8. Tannins in tropical woods

    Energy Technology Data Exchange (ETDEWEB)

    Doat, J.

    1978-01-01

    A preliminary study was made of the chemistry of pyrogallol- and catecholtannins, their general properties and methods of extraction and determination. Three methods of estimation - Lowenthal, powdered hide and spectrophotometry - were compared using two control solutions, four samples of wood and one of bark. Using the empirical powdered hide method, tannins of both types were estimated in wood and bark of various tropical species (some separately and some as a mixture), Moroccan oaks (Quercus suber and Q. ilex), and European oak 9Q. petraea). Further tests were made on the wood and bark of the two mangrove species, Rhizophora mangle and R. racemosa, by subjecting them to successive extraction with a range of solvents. None of the woods tested had as much as the 10% of tannins considered necessary in economic sources. The bark of the two mangroves, of Eucalyptus urophylla and of Prosopis africana had tannin contents over 10% and the latter two species had very favorable tannin/non-tannin ratios. All the tropical species, with the probable exception of E. urophylla, had only catecholtannins. Only the oaks and E. urophylla bark gave positive results when tested for gallotannins.

  9. Effective Stimulus Parameters for Directed Locomotion in Madagascar Hissing Cockroach Biobot.

    Directory of Open Access Journals (Sweden)

    Jonathan C Erickson

    Full Text Available Swarms of insects instrumented with wireless electronic backpacks have previously been proposed for potential use in search and rescue operations. Before deploying such biobot swarms, an effective long-term neural-electric stimulus interface must be established, and the locomotion response to various stimuli quantified. To this end, we studied a variety of pulse types (mono- vs. bipolar; voltage- vs. current-controlled and shapes (amplitude, frequency, duration to parameters that are most effective for evoking locomotion along a desired path in the Madagascar hissing cockroach (G. portentosa in response to antennal and cercal stimulation. We identified bipolar, 2 V, 50 Hz, 0.5 s voltage controlled pulses as being optimal for evoking forward motion and turns in the expected contraversive direction without habituation in ≈50% of test subjects, a substantial increase over ≈10% success rates previously reported. Larger amplitudes for voltage (1-4 V and current (50-150 μA pulses generally evoked larger forward walking (15.6-25.6 cm; 3.9-5.6 cm/s but smaller concomitant turning responses (149 to 80.0 deg; 62.8 to 41.2 deg/s. Thus, the radius of curvature of the initial turn-then-run locomotor response (≈10-25 cm could be controlled in a graded manner by varying the stimulus amplitude. These findings could be used to help optimize stimulus protocols for swarms of cockroach biobots navigating unknown terrain.

  10. Subsocial Cockroaches Nauphoeta cinerea Mate Indiscriminately with Kin Despite High Costs of Inbreeding

    Science.gov (United States)

    Bouchebti, Sofia; Durier, Virginie; Pasquaretta, Cristian; Rivault, Colette; Lihoreau, Mathieu

    2016-01-01

    Many animals have evolved strategies to reduce risks of inbreeding and its deleterious effects on the progeny. In social arthropods, such as the eusocial ants and bees, inbreeding avoidance is typically achieved by the dispersal of breeders from their native colony. However studies in presocial insects suggest that kin discrimination during mate choice may be a more common mechanism in socially simpler species with no reproductive division of labour. Here we examined this possibility in the subsocial cockroach Nauphoeta cinerea, a model species for research in sexual selection, where males establish dominance hierarchies to access females and control breeding territories. When given a binary choice between a sibling male and a non-sibling male that had the opportunity to establish a hierarchy prior to the tests, females mated preferentially with the dominant male, irrespective of kinship or body size. Despite the lack of kin discrimination during mate choice, inbred-mated females incurred significant fitness costs, producing 20% less offspring than outbred-mated females. We discuss how the social mating system of this territorial cockroach may naturally limit the probability of siblings to encounter and reproduce, without the need for evolving active inbreeding avoidance mechanisms, such as kin recognition. PMID:27655156

  11. Endogenous rhythm and pattern-generating circuit interactions in cockroach motor centres

    Directory of Open Access Journals (Sweden)

    Izhak David

    2016-09-01

    Full Text Available Cockroaches are rapid and stable runners whose gaits emerge from the intricate, and not fully resolved, interplay between endogenous oscillatory pattern-generating networks and sensory feedback that shapes their rhythmic output. Here we studied the endogenous motor output of a brainless, deafferented preparation. We monitored the pilocarpine-induced rhythmic activity of levator and depressor motor neurons in the mesothoracic and metathoracic segments in order to reveal the oscillatory networks’ architecture and interactions. Data analyses included phase relations, latencies between and overlaps of rhythmic bursts, spike frequencies, and the dependence of these parameters on cycle frequency. We found that, overall, ipsilateral connections are stronger than contralateral ones. Our findings revealed asymmetries in connectivity among the different ganglia, in which meta-to-mesothoracic ascending coupling is stronger than meso-to-metathoracic descending coupling. Within-ganglion coupling between the metathoracic hemiganglia is stronger than that in the mesothoracic ganglion. We also report differences in the role and mode of operation of homologue network units (manifested by levator and depressor nerve activity. Many observed characteristics are similar to those exhibited by intact animals, suggesting a dominant role for feedforward control in cockroach locomotion. Based on these data we posit a connectivity scheme among components of the locomotion pattern generating system.

  12. CpG Oligodeoxynucleotide Inhibits Cockroach-Induced Asthma via Induction of IFN-γ+ Th1 Cells or Foxp3+ Regulatory T Cells in the Lung

    OpenAIRE

    Kim, Do-Hyun; Sohn, Jung-Ho; Park, Hong-Jai; Lee, Jae-Hyun; Park, Jung-Won; Choi, Je-Min

    2015-01-01

    Purpose CpG oligodeoxynucleotide (CpG-ODN), a TLR9 agonist, activates innate immunity and induces Th1 response. Although the immune modulatory effect of CpG-ODN has been extensively studied, its function in cockroach extract-induced allergic asthma has not been studied. Here, we investigated the inhibitory function of CpG-ODN in cockroach extract-induced asthma in mice with different treatment schemes. Methods Scheme 1: BALB/C mice were intra-nasally co-administered by cockroach extract and C...

  13. Partial transparency of compressed wood

    Science.gov (United States)

    Sugimoto, Hiroyuki; Sugimori, Masatoshi

    2016-05-01

    We have developed novel wood composite with optical transparency at arbitrary region. Pores in wood cells have a great variation in size. These pores expand the light path in the sample, because the refractive indexes differ between constituents of cell and air in lumen. In this study, wood compressed to close to lumen had optical transparency. Because the condition of the compression of wood needs the plastic deformation, wood was impregnated phenolic resin. The optimal condition for high transmission is compression ratio above 0.7.

  14. Aromatic hexamerin subunit from adult female cockroaches (Blaberus discoidalis) : Molecular cloning, suppression by juvenile hormone, and evolutionary perspectives

    NARCIS (Netherlands)

    Jamroz, RC; Beintema, JJ; Stam, WT; Bradfield, JY

    1996-01-01

    In an effort to identify several polypeptides that are strongly suppressed by juvenile hormone (JH) in fat body of adult female Blaberus discoidalis cockroaches, we have cloned a cDNA representing a polypeptide member of the hexamerin family of arthropod serum proteins. The deduced primary translati

  15. The cockroach Blattella germanica obtains nitrogen from uric acid through a metabolic pathway shared with its bacterial endosymbiont.

    Science.gov (United States)

    Patiño-Navarrete, Rafael; Piulachs, Maria-Dolors; Belles, Xavier; Moya, Andrés; Latorre, Amparo; Peretó, Juli

    2014-07-01

    Uric acid stored in the fat body of cockroaches is a nitrogen reservoir mobilized in times of scarcity. The discovery of urease in Blattabacterium cuenoti, the primary endosymbiont of cockroaches, suggests that the endosymbiont may participate in cockroach nitrogen economy. However, bacterial urease may only be one piece in the entire nitrogen recycling process from insect uric acid. Thus, in addition to the uricolytic pathway to urea, there must be glutamine synthetase assimilating the released ammonia by the urease reaction to enable the stored nitrogen to be metabolically usable. None of the Blattabacterium genomes sequenced to date possess genes encoding for those enzymes. To test the host's contribution to the process, we have sequenced and analysed Blattella germanica transcriptomes from the fat body. We identified transcripts corresponding to all genes necessary for the synthesis of uric acid and its catabolism to urea, as well as for the synthesis of glutamine, asparagine, proline and glycine, i.e. the amino acids required by the endosymbiont. We also explored the changes in gene expression with different dietary protein levels. It appears that the ability to use uric acid as a nitrogen reservoir emerged in cockroaches after its age-old symbiotic association with bacteria.

  16. CIRCADIAN CONTROL OF VISUAL INFORMATION-PROCESSING IN THE OPTIC LOBE OF THE GIANT COCKROACH BLABERUS-GIGANTEUS

    NARCIS (Netherlands)

    BULT, R; MASTEBROEK, HAK

    1993-01-01

    Extracellular spike activity from three different types of visual interneurons found in the optic lobe of the giant cockroach Blaberus giganteus was recorded. The spike rate of all three types of neurons fluctuated in a circadian manner in constant darkness (DD). Two types, so-called ''on'' neurons

  17. Wood construction under cold climate

    DEFF Research Database (Denmark)

    Wang, Xiaodong; Hagman, Olle; Sundqvist, Bror;

    2014-01-01

    As wood constructions increasingly use engineered wood products worldwide, concerns arise about the integrity of the wood and adhesives system. The glueline stability is a crucial issue for engineered wood application, especially under cold climate. In this study, Norway spruce (Picea abies...... affected shear strength of wood joints. As temperature decreased, the shear strength decreased. PUR resin resulted in the strongest shear strength at all temperatures tested. MF resin responded to temperature changes in a similar ways as the PUR resin. The shear strength of wood joints with EPI resins...... specimens need to be tested in further work to more completely present the issue. The EN 301 and EN 302 may need to be specified based on wood species....

  18. Nanoscale in Wood, Nanowood and Wood-Inorganic Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Zhao Guangjie; Lu Wenhua

    2003-01-01

    In order to introduce nano science and technology (NST) into the research field of wood science and technology, andpromote the research of wood science and wood-inorganic composites to nanoscale, some new concepts, such as the nano space inwood, nano structure units of wood and nanowood are put forward in this paper based on the layer structure of wood cell wall and thepile-up model of its main components. Furthermore, the process of preparing nanowood is discussed, and wood-inorganic nanocom-posites may be operated in three ways with wood (matrix) and inorganic filler phase in 0-2, 0-3 or 2-3 dimensions respectively. Thefollowing results are obtained: (1) The nanoscale voids in wood indicate that wood has inherent space to accommodate nanosizedmaterials, such as nanoparticles, nanotubes and nanosticks; (2) According to the size from top down, the nano structure units in woodcan be classified as: nanolayers, nano CMF (cellulose microfibril) and matrix, nano crystallite units and cellulose chain clusters, andthese can theoretically form nanowood; (3) The preparation of wood-inorganic nanocomposites can be operated on 0-2, 0-3 or 2-3dimensions.

  19. Distribution of Thelastomatoid Nematodes (Nematoda: Oxyurida) in Endemic and Introduced Cockroaches on the Galápagos Island Archipelago, Ecuador.

    Science.gov (United States)

    Sinnott, Devinn; Carreno, Ramon A; Herrera, Henri

    2015-08-01

    The thelastomatoid pinworm fauna (Nematoda: Oxyurida: Thelastomatoidea) was surveyed in 3 endemic species and 6 introduced species of cockroach hosts (Insecta: Blattaria) in the Galápagos Islands, Ecuador. A total of 658 host specimens were examined from preserved collections that had been collected between 1966 and 2003 from 7 islands in the archipelago. Eight species of pinworms were identified from these cockroach hosts, including the dominant species Cephalobellus ovumglutinosus and a Severianoia sp. as well as Leidynema appendiculata, Hammerschmidtiella diesingi, an unidentified Cephalobellus species resembling Cephalobellus magalhaesi, an unidentified Protrellus species closely resembling Protrellus shamimi, and an undescribed Blattophila sp. Five new host records are identified for C. ovumglutinosus including the endemic Galápagos cockroaches Chorisoneura carpenteri, Ischnoptera snodgrassii, and Ischnoptera santacruzensis. These endemics were also infected with an undescribed Blatticola sp. Other species recorded resemble known pinworms from other hosts around the world. Prevalence between islands and between host species was variable, but total prevalence for individual pinworm species was consistently low (<10%). A single host specimen examined was infected with more than 1 pinworm species; otherwise only a single species was observed in each infected host. At least 1 introduced pinworm species carried to the islands via invasive cockroach hosts was present in endemic host species, but several globally widespread introduced pinworm species were absent from endemic cockroaches. Santa Cruz was inhabited by the greatest number of pinworm species, likely due to a higher rate of invasive host introduction. This survey, the first from this region, showed that the distribution and transmission of pinworms in the Galápagos Islands is complex and may provide future models of invertebrate dispersal and speciation in an ecosystem already rich with examples of

  20. Determination of Fire and Burning Properties of Spruce Wood

    Directory of Open Access Journals (Sweden)

    Martin Zachar

    2012-09-01

    Full Text Available This paper deals with the determination of selected fire properties of spruce wood. It describes the general characteristics of spruce wood, microscopic and macroscopic features. Broad application of this material requires the assessment of its properties regarding the fire aspects, being a cause of fire in forests or due to frequent occurrence of wildland fires in the Slovak territory, and being a flammable material used in building industry, furniture industry, etc. This paper analyses the following fire properties: flash-ignition temperature, spontaneous ignition temperature, mass burning rate, ignitability of material exposed to a small open flame.

  1. Antioxidant properties of wood extracts and colour stability of woods

    OpenAIRE

    Diouf, Papaniokhor; Merlin, André; Perrin, Dominique

    2006-01-01

    Industrial wood extracts were selected and other extracts were prepared in the laboratory from some chosen wood species. Antioxidant capacities of extracts were measured by three methods: the oxygen uptake method, the kinetic DPPH method, and the equilibrium DPPH method. There is a fair correlation between the three methods. Total phenol contents of the extracts and colour stability of woods were measured. For the same phenol content, extracts containing condensed tannins are more antioxidant...

  2. High load of multi-drug resistant nosocomial neonatal pathogens carried by cockroaches in a neonatal intensive care unit at Tikur Anbessa specialized hospital, Addis Ababa, Ethiopia

    OpenAIRE

    Tilahun Birkneh; Worku Bogale; Tachbele Erdaw; Terefe Simegn; Kloos Helmut; Legesse Worku

    2012-01-01

    Abstract Background Cockroaches have been described as potential vectors for various pathogens for decades; although studies from neonatal intensive care units are scarce. This study assessed the vector potential of cockroaches (identified as Blatella germanica) in a neonatal intensive care unit setup in Tikur Anbessa Hospital, Addis Ababa, Ethiopia. Methods A total of 400 Blatella germanica roaches were aseptically collected for five consecutive months. Standard laboratory procedures were us...

  3. Toxicity of Pyrethroid and Organophosphorous Insecticides against Two Field Collected Strains of the German Cockroach Blattella Germanica (Blattaria: Blattellidae) from Hospitals in Hamadan, Iran

    OpenAIRE

    Mojtaba Limoee; Behroz Davari; Seyad Hassan Moosa-Kazemi

    2012-01-01

    Background: The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for path­ogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos) against two hospital- collected strains of the German cockroach was investigated.Methods: Topical bioassay methods were carried out for detecting ...

  4. Nondestructive wood discrimination: FTIR - Fourier Transform Infrared Spectroscopy in the characterization of different wood species used for artistic objects

    Science.gov (United States)

    Buoso, Maria Crista; de Poli, Mario; Matthaes, Peter; Silvestrin, Luca; Zafiropoulos, Demetre

    2016-09-01

    Wooden artifacts represent a significant component of past cultures. Successful conservation of wooden artifacts depends on the knowledge of wood structure and types. It is critical that conservators know the category of wood that they are treating in order to successfully conserve it. Recently, vibrational spectroscopy has been successfully applied to determine the chemical structure of wood and to characterize wood types. FTIR (Fourier Transform Infrared) is a useful nondestructive or micro-destructive analytical technique providing information about chemical bonding and molecular structure. Its application in the discrimination between softwoods (conifers) and hardwoods (broad-leafs) has already been reported. The aim of the present study was to investigate the potential of FTIR as a tool for the discrimination between different wood types belonging to the same genus. Three different hardwood species, namely poplar (Populus spp), lime (Tilia spp) and birch (Betula spp), were investigated by means of FTIR spectroscopy. The woods were first inspected using a light microscope to certify the wood essence types through micrographic and morphoanatomical features. The FTIR spectra in the 4000 cm-1 to 450 cm-1 region were recorded using a Perkin-Elmer Spectrum 100 spectrometer. To enhance the qualitative interpretation of the IR spectra, second derivatives of all spectra were calculated using the Spectrum software to separate superimposed bands and to extract fine spectral details. To obtain a comprehensive characterization, the essences under investigation were also analyzed by means of Raman Spectroscopy. Clear differences were found in the spectra of the three samples confirming FTIR to be a powerful tool for wood type discrimination.

  5. The First Report of Drug Resistant Bacteria Isolated from the Brown-Banded Cockroach, Supella longipalpa, in Ahvaz, South-western Iran.

    Directory of Open Access Journals (Sweden)

    Babak Vazirianzadeh

    2014-06-01

    Full Text Available The brown-banded cockroach, Supella longipalpa is known as a carrier of pathogenic bacteria in urban environments, but its role is not well documented regarding the carriage of antibiotic-resistant pathogenic bacteria in Iran. The aim of this study was to determine the resistance bacteria isolated from the brown-banded cockroach in Ahvaz, south west of Iran.Totally 39 cockroaches were collected from kitchen area of houses and identified. All specimens were cultured to isolate the bacterial agents on blood agar and MacConky agar media. The microorganisms were identified using necessary differential and biochemical tests. Antimicrobial susceptibility tests were performed for isolated organisms by Kirby-Bauer's disk diffusion according to NCLI guideline, using 18 antibiotics.From the 39 collected S. langipalpa, 179 bacterial agents were isolated, 92 of alimentary ducts and 87 of external body surfaces. Isolated bacteria from cockroaches were identified as Enterobacter spp., Klebsiella spp., Citrobacter spp., Escherichia coli, Salmonella spp., Proteus spp., coagulase negative staphylococci, Serratia marcescens, Staphylococcus aureus, and Bacillus species. The pattern resistance rates were determined for gram negative bacilli and gram positive cocci regarding 18 antibiotics.The brown-banded cockroach can be involved in the spread of drug resistant bacteria and increases the possibility of contacting human environment to drug resistant bacteria. Therefore, the potential of removing this insect should be improved. This is the first original report of drug resistant bacteria isolated from the brown-banded cockroach of Iran.

  6. HISTORICAL DEVELOPMENTS IN WOOD CHEMISTRY

    OpenAIRE

    YOUNG, Raymond A.

    2009-01-01

    Wood are one of the most important raw material source for forest products industry. Due to technological developments, researchers in the area of wood chemistry have been showing increased interest in the benefits of utilization wood based materials alone or together as an alternative lignocellulosic fiber sources for forest products industry. However, utilization of woody matrials more efficiently and conservation natural resources have been paid special attention. For that reason...

  7. Horizontal Stiffness of Wood Diaphragms

    OpenAIRE

    Bott, James Wescott

    2005-01-01

    An experimental investigation was conducted to study the stiffness of wood diaphragms. Currently there is no method to calculate wood diaphragm stiffness that can reliably account for all of the various framing configurations. Diaphragm stiffness is important in the design of wood framed structures to calculate the predicted deflection and thereby determine if a diaphragm may be classified as rigid or flexible. This classification controls the method by which load is transferred from the d...

  8. Wood products and green chemistry

    OpenAIRE

    Antonio PIZZI

    2016-01-01

    International audience Key message Green chemistry for and from wood has developed numerous industrial products, namely biosourced, green wood adhesives and preservatives, foams, composite matrices, laminates, hard and flexible plastics, flexible films, and abrasive grinding discs, and their number is still growing.IntroductionThis review addresses (1) the elimination of toxic aldehydes from the most common wood panel adhesive, the one based on urea, itself a natural product, (2) biosource...

  9. Light-mimicking cockroaches indicate Tertiary origin of recent terrestrial luminescence

    Science.gov (United States)

    Vršanský, Peter; Chorvát, Dušan; Fritzsche, Ingo; Hain, Miroslav; Ševčík, Robert

    2012-09-01

    Bioluminescence is a common feature of the communication and defence of marine organisms, but this phenomenon is highly restricted in the terrestrial biota. Here, we present a geographical distribution of only the third order of luminescent insects—luminescent cockroaches, with all 13 known and/or herein reported new living species (based on deposited specimens). We show that, for the first time, photo-characteristics of three examined species are nearly identical with those of toxic luminescent click beetles, which they mimic. These observations are the evidence for the mimicry by light—a new type of defensive, Batesian and interordinal mimicry. Our analysis surprisingly reveals an evolutionary novelty of all living luminescent insects, while in the sea (and possibly in the soil) luminescence is present also phylogenetically in very primitive organisms.

  10. Impact of deltamethrin on cockroaches (Periplaneta americana and its residue on environment

    Directory of Open Access Journals (Sweden)

    Endang Puji Astuti

    2015-01-01

    Full Text Available AbstrakLatar belakang: Penggunaan insektisida secara intensif tidak hanya memberikan dampak pada spesies target, namun juga pada spesies non-target dan lingkungan. Pada penelitian ini dilakukan penilaian pengaruh residu deltametrin terhadap kecoa (Periplanetaamericana, ikan lele (Clarias batrachus, dan nila (Oreochromis niloticus. Selain itu laju infiltrasi residu pada tipe tanah dengan komposisi tanah yang berbeda juga diukur. Metode: Percobaan dilakukan terhadap kecoa yang dikembangbiakan  di laboratorium di Institut Pertanian Bogor. Perlakuan dengan tiga ulangan dan lima taraf konsentrasi deltamethrin: 0.8%, 0.4%, 0.2%, 0.1% and 0.05% (v/v dilakukan untuk mengukur pengaruh residu terhadap kecoa selama 24 dan 48 jam. Penentuan LC  dilakukan dengan analisis Probit. Konsentrasi letal yang didapatkan kemudiandiujikan kepada ikan lele dan nila dengan metode semprot. Untuk perbandingan, uji efek organofosfat dengan konsentrasi 1 ppm dan 10 ppm dilakukan melalui metode soaking kepada dua jenis ikan tersebut. Laju infiltrasi residu pada tiga tipe komposisi tanah diukur menggunakan lysimeter. Hasil: Hasil penelitian menunjukkan bahwa LC50 residu deltamethrin terhadap kecoa tercapai pada konsentrasi 0,2% pada 24-jam perlakuan. Lima puluh persen ikan nila mati pada perlakuan deltamethrin0,2% selama 24 jam. Laju infiltrasi residu lebih tinggi pada jenis tanah berpasir (5 ml/menit dibandingkan jenis tanah yang didominasi tanah liat. Kesimpulan: Selain memiliki efek mematikan pada kecoa, Deltamethrin 0,2% mencemari tanah dan air, serta membunuh ikan nila (O. niloticus. (Health Science Indones 2014;2:94-9Kata kunci: deltamethrin, efek residu, P. americana, O. niloticus, tanahAbstractBackground: Intensive use of chemical insecticides not only affect the targetspecies, but also non-target species and environment. In this study, we examined residual effect of deltamethrin on cockroaches (Periplaneta americana, catfishes (Clarias batrachus and nile

  11. Establishing health standards for indoor foreign proteins related to asthma: Dust mite, cat and cockroach

    Energy Technology Data Exchange (ETDEWEB)

    Platts-Mills, T.A.E.; Chapman, M.D.; Pollart, S.M.; Heymann, P.W.; Luczynska, C.M. (Univ. of Virginia, Charlottesville (United States))

    1990-01-01

    There is no doubt that a large number of individuals become allergic to foreign proteins that are predominantly or exclusively present indoors. In each case this immune response can be demonstrated either by immediate skin test responses or by measuring serum IgE antibodies. It has also been obvious for some time that patients presenting with asthma, perennial rhinitis and atopic dermatitis have an increased prevalence of IgE antibodies to these indoor allergens. More recently several epidemiological surveys have suggested that both mite exposure and IgE antibodies are important risk factors for asthma. The present situation is that assays have been developed capable of measuring the presence of mite, cockroach and cat allergens in house dust. Further clinical studies will be necessary to test the proposed standards for mite allergens and to define risk levels for other allergens.

  12. Hierarchical genetic analysis of German cockroach (Blattella germanica) populations from within buildings to across continents.

    Science.gov (United States)

    Vargo, Edward L; Crissman, Jonathan R; Booth, Warren; Santangelo, Richard G; Mukha, Dmitry V; Schal, Coby

    2014-01-01

    Understanding the population structure of species that disperse primarily by human transport is essential to predicting and controlling human-mediated spread of invasive species. The German cockroach (Blattella germanica) is a widespread urban invader that can actively disperse within buildings but is spread solely by human-mediated dispersal over longer distances; however, its population structure is poorly understood. Using microsatellite markers we investigated population structure at several spatial scales, from populations within single apartment buildings to populations from several cities across the U.S. and Eurasia. Both traditional measures of genetic differentiation and Bayesian clustering methods revealed increasing levels of genetic differentiation at greater geographic scales. Our results are consistent with active dispersal of cockroaches largely limited to movement within a building. Their low levels of genetic differentiation, yet limited active spread between buildings, suggests a greater likelihood of human-mediated dispersal at more local scales (within a city) than at larger spatial scales (within and between continents). About half the populations from across the U.S. clustered together with other U.S. populations, and isolation by distance was evident across the U.S. Levels of genetic differentiation among Eurasian cities were greater than those in the U.S. and greater than those between the U.S. and Eurasia, but no clear pattern of structure at the continent level was detected. MtDNA sequence variation was low and failed to reveal any geographical structure. The weak genetic structure detected here is likely due to a combination of historical admixture among populations and periodic population bottlenecks and founder events, but more extensive studies are needed to determine whether signatures of global movement may be present in this species. PMID:25020136

  13. Hierarchical genetic analysis of German cockroach (Blattella germanica populations from within buildings to across continents.

    Directory of Open Access Journals (Sweden)

    Edward L Vargo

    Full Text Available Understanding the population structure of species that disperse primarily by human transport is essential to predicting and controlling human-mediated spread of invasive species. The German cockroach (Blattella germanica is a widespread urban invader that can actively disperse within buildings but is spread solely by human-mediated dispersal over longer distances; however, its population structure is poorly understood. Using microsatellite markers we investigated population structure at several spatial scales, from populations within single apartment buildings to populations from several cities across the U.S. and Eurasia. Both traditional measures of genetic differentiation and Bayesian clustering methods revealed increasing levels of genetic differentiation at greater geographic scales. Our results are consistent with active dispersal of cockroaches largely limited to movement within a building. Their low levels of genetic differentiation, yet limited active spread between buildings, suggests a greater likelihood of human-mediated dispersal at more local scales (within a city than at larger spatial scales (within and between continents. About half the populations from across the U.S. clustered together with other U.S. populations, and isolation by distance was evident across the U.S. Levels of genetic differentiation among Eurasian cities were greater than those in the U.S. and greater than those between the U.S. and Eurasia, but no clear pattern of structure at the continent level was detected. MtDNA sequence variation was low and failed to reveal any geographical structure. The weak genetic structure detected here is likely due to a combination of historical admixture among populations and periodic population bottlenecks and founder events, but more extensive studies are needed to determine whether signatures of global movement may be present in this species.

  14. Wood pole overhead lines

    CERN Document Server

    Wareing, Brian

    2005-01-01

    This new book concentrates on the mechanical aspects of distribution wood pole lines, including live line working, environmental influences, climate change and international standards. Other topics include statutory requirements, safety, profiling, traditional and probabilistic design, weather loads, bare and covered conductors, different types of overhead systems, conductor choice, construction and maintenance. A section has also been devoted to the topic of lightning, which is one of the major sources of faults on overhead lines. The book focuses on the effects of this problem and the strate

  15. Wood-Based Bioenergy

    OpenAIRE

    Hoel, Michael; Sletten, Thea Marcelia

    2014-01-01

    During recent years increased attention has been given to second-generation wood-based bioenergy. The carbon stored in the forest is highest when there is little or no harvest from the forest. Increasing the harvest from a forest, in order to produce more bioenergy, may thus conflict with the direct benefit of the forest as a carbon sink. We analyze this conflict using a simple model where bioenergy and fossil energy are perfect substitutes. Our analysis shows how the social optimum will depe...

  16. Testing decreasing variabililty of cockroach forewings through time using four Recent species: Blattella germanica,Polyphaga aegyptiaca, Shelfordella lateralis and Blaberus craniifer, with implications for the study of fossil cockroach forewings

    Institute of Scientific and Technical Information of China (English)

    Andrew J. Ross

    2012-01-01

    Vr(s)ansk(y) (2000) considered there is decreasing variability in the forewings of cockroaches through time,based on a study of fossil and Recent species.This study tests his theory,based on a study of four Recent species of cockroaches:Blattella germanica (Blattellidae),Polyphaga aegyptiaca (Polyphagidae),Shelfordella lateralis (Blattidae) and Blaberus craniifer (Blaberidae).The new results,based on the coefficient of variation (CV) of the number of veins,indicate that Recent species can be more variable than fossil species and therefore do not support the theory.The results also show that at least 30 complete wings of the same species are required for a reliable CV value that is comparable between species.

  17. Improvment of wood-residues conversion technology

    OpenAIRE

    Posharnikov, Feliks; Bazarskaya, Nina; Bulanov, Aleksandr

    2011-01-01

    The problem of wood residues conversion is considered. The sizes-based types of wood residues and results of wood residues conversion are presented. Sawdust-based-cement a new original product is offered

  18. Wood-related occupations, wood dust exposure, and sinonasal cancer.

    Science.gov (United States)

    Hayes, R B; Gerin, M; Raatgever, J W; de Bruyn, A

    1986-10-01

    A case-control study was conducted to examine the relations between type of woodworking and the extent of wood dust exposure to the risks for specific histologic types of sinonasal cancer. In cooperation with the major treatment centers in the Netherlands, 116 male patients newly diagnosed between 1978 and 1981 with primary malignancies of epithelial origin of this site were identified for study. Living controls were selected from the municipal registries, and deceased controls were selected from the national death registry. Interviews were completed for 91 (78%) cases and 195 (75%) controls. Job histories were coded by industry and occupation. An index of exposure was developed to classify the extent of occupational exposure to wood dust. When necessary, adjustment was made for age and usual cigarette use. The risk for nasal adenocarcinoma was elevated by industry for the wood and paper industry (odds ratio (OR) = 11.9) and by occupation for those employed in furniture and cabinet making (OR = 139.8), in factory joinery and carpentry work (OR = 16.3), and in association with high-level wood dust exposure (OR = 26.3). Other types of nasal cancer were not found to be associated with wood-related industries or occupations. A moderate excess in risk for squamous cell cancer (OR = 2.5) was associated with low-level wood dust exposure; however, no dose-response relation was evident. The association between wood dust and adenocarcinoma was strongest for those employed in wood dust-related occupations between 1930 and 1941. The risk of adenocarcinoma did not appear to decrease for at least 15 years after termination of exposure to wood dust. No cases of nasal adenocarcinoma were observed in men whose first exposure to wood dust occurred after 1941.

  19. Wood gas; Holz gibt Gas

    Energy Technology Data Exchange (ETDEWEB)

    Hilgers, Claudia

    2011-06-17

    Sixty years ago, wood gas was even used as a car fuel. Today, this ancient technology is experiencing a renaissance. Small cogeneration plants with wood gasifiers are ideal for renewable and decentral power supply concepts for tomorrow. Until then, there is much pioneering work to do until plants will be ready for serial production.

  20. Preservation of forest wood chips

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, P.D.; Thomsen, I.M.; Ohlsson, C.; Leer, E.; Ravn Schmidt, E.; Soerensen, M.; Knudsen, P.

    1999-01-01

    As part of the Danish Energy Research Programme on biomass utilisation for energy production (EFP), this project concerns problems connected to the handling and storing of wood chips. In this project, the possibility of preserving wood chips of the Norway Spruce (Picea Abies) is addressed, and the potential improvements by anaerobic storage are tested. Preservation of wood chips aims at reducing dry matter losses from extensive heating during storage and to reduce production of fungal spores. Fungal spores pose a health hazards to workers handling the chips. Further the producers of wood chips are interested in such a method since it would enable them to give a guarantee for the delivery of homogeneous wood chips also during the winter period. Three different types of wood chips were stored airtight and further one of these was stored in accordance with normal practise and use as reference. The results showed that airtight storage had a beneficial impact on the quality of the chips: no redistribution of moisture, low dry matter losses, unfavourable conditions for microbial activity of most fungi, and the promotion of yeasts instead of fungi with airborne spores. Likewise the firing tests showed that no combustion problems, and no increased risk to the environment or to the health of staff is caused by anaerobic storage of wood chips. In all, the tests of the anaerobic storage method of forest wood chips were a success and a large-scale test of the method will be carried out in 1999. (au)

  1. Integrating Hot and Cool Intelligences: Thinking Broadly about Broad Abilities

    Directory of Open Access Journals (Sweden)

    W. Joel Schneider

    2016-01-01

    Full Text Available Although results from factor-analytic studies of the broad, second-stratum abilities of human intelligence have been fairly consistent for decades, the list of broad abilities is far from complete, much less understood. We propose criteria by which the list of broad abilities could be amended and envision alternatives for how our understanding of the hot intelligences (abilities involving emotionally-salient information and cool intelligences (abilities involving perceptual processing and logical reasoning might be integrated into a coherent theoretical framework.

  2. Programmed Death-1 Antibody Blocks Therapeutic Effects of T-Regulatory Cells in Cockroach Antigen-Induced Allergic Asthma

    OpenAIRE

    McGee, Halvor S; Yagita, Hideo; Shao, Zhifei; Devendra K Agrawal

    2009-01-01

    We recently reported that the adoptive transfer of T-regulatory cells (Tregs) isolated from lung and spleen tissue of green fluorescent protein–transgenic mice reversed airway hyperresponsiveness and airway inflammation. Because Programmed Death-1 (PD-1) is a pivotal receptor regulating effector T-cell activation by Tregs, we evaluated whether PD-1 is involved in the therapeutic effect of naturally occurring Tregs (NTregs) and inducible Tregs (iTregs) in cockroach (CRA)-sensitized and challen...

  3. Design Wood Nanocomposites from Polymer Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    LVWenhua; ZHAOGuangjie

    2004-01-01

    Researches on wood nanocomposites, which involve nano science and technology, wood science,materials science and other related subjects, have important science signification and promising prospect for the development and study of new wood composites with high appending values and multi-properties. This paper reviewed the conventional wood composites, and then discussed the approaches to prepare wood nanocomposites. Based on the achievements of researches on polymer/montmorillonite (MMT) nanocomposites, the design ideas of preparing nanocomposites of wood and inorganic MMT were systematically put forward. Nano compounding of wood and other materials is an effective approach to greatly improve or modify wood.

  4. Integration of repellents, attractants, and insecticides in a "push-pull" strategy for managing German cockroach (Dictyoptera: Blattellidae) populations.

    Science.gov (United States)

    Nalyanya, G; Moore, C B; Schal, C

    2000-05-01

    "Push-pull" is a behavior manipulation strategy in which behavior-modifying stimuli are integrated with a pest control agent. We evaluated the efficacy of an insecticide bait in combination with attractants ("pull"), repellents ("push"), or both ("push-pull") using a hydramethylnon-based bait, feces-contaminated surfaces as an attractant, and methyl neodecanamide-treated surfaces to repel cockroaches. Both adult males and first-instar German cockroaches, Blattella germanica (L.), chose shelters nearest the attractant-treated surfaces and farthest from the repellent-treated surfaces. Food consumption was highest from food nearest the preferred shelters, and mortality was highest when the insecticide bait was near the preferred shelter. These patterns were more apparent in first instars than in adults. Our results from large arena studies in the laboratory show that the push-pull strategy can be used to displace pests from resources or commodities that are to be protected, and simultaneously lure the pest to an attractant source coupled with a pest control agent. Concentrating cockroaches into a limited area should facilitate the precision-targeting of the pest population and promises to reduce insecticide use.

  5. Utilizing wood wastes as reinforcement in wood cement composite bricks

    Directory of Open Access Journals (Sweden)

    Nusirat Aderinsola Sadiku

    2015-07-01

    Full Text Available This paper presents the research work undertaken to study the properties of Wood Cement Composite Bricks (WCCB from different wood wastes and cement / wood content. The WCBBs with nominal density of 1200 kg m-3 were produced from three tropical wood species and at varying cement and wood content of 2:1, 2.5:1 and 3:1 on a weight to weight basis. The properties evaluated were compressive strength, Ultra Pulse Velocity (UPV, water absorption (WA and thickness swelling (TS. The Compressive strength values ranged from 0.25 to 1.13 N mm-2 and UPV values ranged from 18753 to 49992 m s-1. The mean values of WA after 672 hours (28 days of water soaking of the WCCBs ranged from 9.50% to 47.13% where there were no noticeable change in the TS of the bricks. The observed density (OD ranged from 627 to 1159 kg m-3. A. zygia from the three wood/cement content were more dimensionally stable and better in compressive strength than the other two species where T. scleroxylon had the best performance in terms of UPV. All the properties improved with increasing cement content. WCCBs at 3.0:1 cement/wood content are suitable for structural application such as panelling, ceiling and partitioning

  6. Cooling of wood briquettes

    Directory of Open Access Journals (Sweden)

    Adžić Miroljub M.

    2013-01-01

    Full Text Available This paper is concerned with the experimental research of surface temperature of wood briquettes during cooling phase along the cooling line. The cooling phase is an important part of the briquette production technology. It should be performed with care, otherwise the quality of briquettes could deteriorate and possible changes of combustion characteristics of briquettes could happen. The briquette surface temperature was measured with an IR camera and a surface temperature probe at 42 sections. It was found that the temperature of briquette surface dropped from 68 to 34°C after 7 minutes spent at the cooling line. The temperature at the center of briquette, during the 6 hour storage, decreased to 38°C.

  7. Wood Bond Testing

    Science.gov (United States)

    1989-01-01

    A joint development program between Hartford Steam Boiler Inspection Technologies and The Weyerhaeuser Company resulted in an internal bond analyzer (IBA), a device which combines ultrasonics with acoustic emission testing techniques. It is actually a spinoff from a spinoff, stemming from a NASA Lewis invented acousto-ultrasonic technique that became a system for testing bond strength of composite materials. Hartford's parent company, Acoustic Emission Technology Corporation (AET) refined and commercialized the technology. The IBA builds on the original system and incorporates on-line process control systems. The IBA determines bond strength by measuring changes in pulsar ultrasonic waves injected into a board. Analysis of the wave determines the average internal bond strength for the panel. Results are displayed immediately. Using the system, a mill operator can adjust resin/wood proportion, reduce setup time and waste, produce internal bonds of a consistent quality and automatically mark deficient products.

  8. Wood would burn

    International Nuclear Information System (INIS)

    Absract: In view of the world-wide problem of energy sustainability and greenhouse gas production (carbon dioxide), it is timely to review the issues involved in generating heat and power from all fuels and especially new (to the UK) solid fuels, including high moisture fuels such as wood, SRF, oil shale, tar sands and brown coal, which will become major international fuels as oil and gas become depleted. The combustion properties of some of these materials are significantly different from traditional coal, oil and gas fuels, however the technology proposed herein is also applicable to these conventional fuels. This paper presents some innovative combustion system options and the associated technical factors that must be considered for their implementation. For clarity of understanding, the novel concepts will be largely presented in terms of a currently developing solid fuel market; biomass wood chips. One of the most important characteristics of many solid fuels to be used in the future (including oil shale and brown coal) is their high moisture content of up to 60%. This could be removed by utilising low grade waste heat that is widely available in industry to dry the fuel and thus reduce transport costs. Burning such dried wood for power generation also increases the energy available from combustion and thus acts as a thermal transformer by upgrading the low grade heat to heat available at combustion temperatures. The alternative approach presented here is to recover the latent heat by condensing the extrinsic moisture and the water formed during combustion. For atmospheric combustion, the temperature of the condensed combustion products is below the dew point at about 55-65 oC and is only suitable for recovery in an efficient district heating system. However, in order to generate power from the latent heat, the condensation temperature must be increased to the level where the heat can be used in the thermodynamic power cycle. This can be achieved by increasing

  9. Enzymatic hydrolysis of biomass from wood.

    Science.gov (United States)

    Álvarez, Consolación; Reyes-Sosa, Francisco Manuel; Díez, Bruno

    2016-03-01

    Current research and development in cellulosic ethanol production has been focused mainly on agricultural residues and dedicated energy crops such as corn stover and switchgrass; however, woody biomass remains a very important feedstock for ethanol production. The precise composition of hemicellulose in the wood is strongly dependent on the plant species, therefore different types of enzymes are needed based on hemicellulose complexity and type of pretreatment. In general, hardwood species have much lower recalcitrance to enzymes than softwood. For hardwood, xylanases, beta-xylosidases and xyloglucanases are the main hemicellulases involved in degradation of the hemicellulose backbone, while for softwood the effect of mannanases and beta-mannosidases is more relevant. Furthermore, there are different key accessory enzymes involved in removing the hemicellulosic fraction and increasing accessibility of cellulases to the cellulose fibres improving the hydrolysis process. A diversity of enzymatic cocktails has been tested using from low to high densities of biomass (2-20% total solids) and a broad range of results has been obtained. The performance of recently developed commercial cocktails on hardwoods and softwoods will enable a further step for the commercialization of fuel ethanol from wood. PMID:26833542

  10. Synergistic effect of some essential oils on toxicity and knockdown effects, against mosquitos, cockroaches and housefly

    Directory of Open Access Journals (Sweden)

    Idin Zibaee

    2015-12-01

    Full Text Available The toxicity and knockdown effect of Eucalyptus globulus, Rosmarinus officinalis essential oils and their mixed formulation on Periplaneta Americana (L., Blattella germanica (L., Supella longipalpa, Culex pipiens, Anopheles stephensi and Musca domestica were evaluated in a series of laboratory experiments. In all bioassay five different doses (0.625, 1.25, 2.5, 5 and 10% were used by filter paper (cm2 and aerosol (cm3 bioassay methods, all essential oils was toxic to cockroaches, mosquitos and housefly species the lowest and the highest LC50 belong to mixed formulation on B. germanica (LC50 6.1 and E. globulus on P. americana (LC50 27.7 respectively. In continuous exposure experiments, Mortality (LT50 values for cockroaches ranged from 1403.3 min with 0.625% E. globulus (for P. americana to 2.2 min with 10% mixed formulation for A. stephensi. The KT50 values ranged from 0.1 to 1090.8 min for 10% and 0.625 for mixed formulation and R. officinalis respectively. The mortality after 24 h for mixed formulation was 100% but for single essential oils ranged from 81.5 to 98.3 for P. americana treated with R. officinalis and A. stephensi treated with E. globulus respectively. Studies on persistence of essential oils on impregnated paper revealed that it has more adulticidal activity for longer period at low storage temperature. Gas chromatographic-mass spectrometric analysis of essential oil showed 14 and 16 peaks for E. globules and R. officinalis respectively. α-Pinene (39.8%, 1, 8-Cineole (13.2%, Camphene (9.1% and Borneol (3.7% were present in major amounts for R. officinalis and 1,8-Cineole (31.4%, α-Pinene (15.3%, d-Limonene (9.7% and α-Terpinolen (5.3% were present in major amounts for E. globulus respectively. Our results showed that two surveyed essential oils has compatible with synergistic effect on various insect species, furthermore it is useful for applying as integrated pest management tool for studied insects management, especially in

  11. COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

    Directory of Open Access Journals (Sweden)

    Yalçın ÖRS

    1999-03-01

    Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

  12. A CONTINUING REVERENCE FOR WOOD

    Directory of Open Access Journals (Sweden)

    Martin A. Hubbe

    2010-02-01

    Full Text Available Our ancestors knew a great deal about wood. They had to in order to do well in life. Wood has played a dominant role in human infrastructure for many generations, and for most of that time woodcraft has depended on the decentralized knowledge passed down among families and guilds. This editorial, while celebrating the knowledge, skills, and insights of the woodworkers of past generations, also calls for a renewed attention to wood’s unique character, including characteristics that today are too often classified as “defects.” We may need to take lessons from generations past to truly derive the best value from wood resources.

  13. Direct and indirect drivers of instream wood in the interior Pacific Northwest, USA: decoupling climate, vegetation, disturbance, and geomorphic setting

    Directory of Open Access Journals (Sweden)

    Hough-Snee Nate

    2014-06-01

    Full Text Available Instream wood is a driver of geomorphic change in low-order streams, frequently altering morphodynamic processes. Instream wood is a frequently measured component of streams, yet it is a complex metric, responding to ecological and geomorphic forcings at a variety of scales. Here we seek to disentangle the relative importance of physical and biological processes that drive wood growth and delivery to streams across broad spatial extents. In so doing, we ask two primary questions: (1 is riparian vegetation a composite variable that captures the indirect effects of climate and disturbance on instream wood dynamics? (2 What are the direct and indirect relationships between geomorphic setting, vegetation, climate, disturbance, and instream wood dynamics? We measured riparian vegetation composition and wood frequency and volume at 720 headwater reaches within the American interior Pacific Northwest. We used ordination to identify relationships between vegetation and environmental attributes, and subsequently built a structural equation model to identify how climate and disturbance directly affect vegetation composition and how vegetation and geomorphic setting directly affect instream wood volume and frequency. We found that large wood volume and frequency are directly driven by vegetation composition and positively correlated to wildfire, elevation, stream gradient, and channel bankfull width. Indicator species at reaches with high volumes of wood were generally long-lived, conifer trees that persist for extended durations once delivered to stream habitats. Wood dynamics were also indirectly mediated by factors that shape vegetation: wildfire, precipitation, elevation, and temperature. We conclude that wood volume and frequency are driven by multiple interrelated climatic, geomorphic, and ecological variables. Vegetation composition and geomorphic setting directly mediate indirect relationships between landscape environmental processes and instream

  14. Wood Technology: Techniques, Processes, and Products

    Science.gov (United States)

    Oatman, Olan

    1975-01-01

    Seven areas of wood technology illustrates applicable techniques, processes, and products for an industrial arts woodworking curriculum. They are: wood lamination; PEG (polyethylene glycol) diffusion processes; wood flour and/or particle molding; production product of industry; WPC (wood-plastic-composition) process; residential construction; and…

  15. Fire Safety Design of Wood Structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2006-01-01

    Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections.......Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections....

  16. Potential wood protection strategies using physiological requirements of wood degrading fungi

    NARCIS (Netherlands)

    Sailer, M.F.; Etten, B.D. van

    2004-01-01

    Due to the increasing restrictions in the use of wood preserving biocides a number of potential biocide free wood preserving alternatives are currently assessed. Wood degrading fungi require certain conditions in the wood in order to be able to use wood as a food source. This paper discusses the phy

  17. Wood-pastures of Europe

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Hartel, Tibor; Martín-López, Berta;

    2015-01-01

    and conservation policies has proved to be complicated, because institutional structures are traditionally organized within mono-functional sectors. We offer suggestions as to how these shortcomings might be overcome in the Common Agricultural Policy, including Rural Development policy, and the Habitats Directive......Wood-pastures are archetypes of High Nature Value Farmlands in Europe and hold exceptional ecological, social, and cultural values. Yet, wood-pastures have been through a sharp decline all over Europe, mainly due to processes of agricultural intensification and abandonment. Recently, wood......-pastures have found increasing attention from conservation science and policy across Europe. In this paper we (i) perform the first pan-European assessment of wood-pastures, considering individual countries and biogeographic regions, (ii) present the ecological and social-cultural values of a wide diversity...

  18. Marketing for Wood Products Companies

    OpenAIRE

    Smith, Robert L; Hansen, Eric; Ola, David

    2009-01-01

    Explains the principles of marketing for wood products organizations and their managers, and includes a list of information resources and agencies that can assist in development of a good marketing program.

  19. EVOLUTION OF LIGHTWEIGHT WOOD COMPOSITES

    OpenAIRE

    Marius C. BARBU

    2016-01-01

    Lightweight boards and beams in the wood-based construction and furniture industry are not a new topic. The density reduction of panels using sandwich structure with light cores was confirmed by users like doors or mobile homes more than three decades ago. Today many ways to attain a lighter wooden structure are on offer, partially in industrial application. The first one is the use of light-weight wood species like balsa, lime, pine from southern hemisphere plantations etc. limit...

  20. Origin of origami cockroach reveals long-lasting (11 Ma) phenotype instability following viviparity

    Science.gov (United States)

    Vršanský, Peter V.; Šmídová, Lucia; Valaška, Daniel; Barna, Peter; Vidlička, Ľubomír; Takáč, Peter; Pavlik, Lubomir; Kúdelová, Tatiana; Karim, Talia S.; Zelagin, David; Smith, Dena

    2016-10-01

    Viviparity evolved in bacteria, plants, ˃141 vertebrate lineages (ichthyosaurs, lizards, fishes, mammals, and others), and in 11 of 44 insect orders. Live-birth cockroaches preserved with brood sac (3D recovered two times optically) included Diploptera vladimir, Diploptera savba, Diploptera gemini spp.n., D. sp.1-2, and Stegoblatta irmgardgroehni from Green River, Colorado; Quilchena, Republic; McAbee, Canada; and Baltic amber, Russia (49, 54, and 45 Ma). They evolved from rare and newly evolved Blaberidae; they radiated circumtropically, later expanded into SE Asia, and have now spread to Hawaii and the SE USA. Association of autapomorphic characters that allow for passive and active protections from parasitic insects (unique wing origami pleating identical with its egg case-attacking wasp) suggest a response to high parasitic loads. Synchronized with global reorganization of the biota, morphotype destabilization in roaches lasted approximately 11-22 Ma, including both the adaptation of novel characters and the reduction of others. Thus, while viviparity can be disadvantageous, in association with new Bauplans and/or behaviors, it can contribute to the evolution of taxa with viviparous representatives that are slightly selectively preferred.

  1. Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability

    Science.gov (United States)

    Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C. Ruth; Jensen, Kim; Hunt, John

    2015-01-01

    It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. PMID:25608881

  2. Variation in the mechanical properties of tracheal tubes in the American cockroach

    Science.gov (United States)

    Becker, Winston R.; Webster, Matthew R.; Socha, John J.; De Vita, Raffaella

    2014-05-01

    The insect cuticle serves the protective role of skin and the supportive role of the skeleton while being lightweight and flexible to facilitate flight. The smart design of the cuticle confers camouflage, thermo-regulation, communication, self-cleaning, and anti-wetting properties to insects. The mechanical behavior of the internal cuticle of the insect in tracheae remains largely unexplored due to their small size. In order to characterize the material properties of insect tracheae and understand their role during insect respiration, we conducted tensile tests on ring sections of tracheal tubes of American cockroaches (Periplaneta americana). A total of 33 ring specimens collected from 14 tracheae from the upper thorax of the insects were successfully tested. The ultimate tensile strength (22.6 ± 13.3 MPa), ultimate strain (1.57 ± 0.68%), elastic modulus (1740 ± 840 MPa), and toughness (0.175 ± 0.156 MJ m-3) were measured. We examined the high variance in mechanical properties statistically and demonstrated that ring sections excised from the same trachea exhibit comparable mechanical properties. Our results will form the basis for future studies aimed at determining the structure-function relationship of insect tracheal tubes, ultimately inspiring the design of multi-functional materials and structures.

  3. Laboratory Evaluation of Toxicity of Insecticide Formulations from Different Classes against American Cockroach (Dictyoptera: Blattidae.

    Directory of Open Access Journals (Sweden)

    Ruhma Syed

    2014-06-01

    Full Text Available The present study was designed to investigate the insecticidal efficacy of four different classes of insecticides: pyrethroids, organophosphates, phenyl-pyrazoles and neo-nicotenoids. One representative chemical from each class was selected to compare the toxicity: deltamethrin from pyrethroids, Dichlorovinyl Dimethyl Phosphate (DDVP from organophosphates, fipronil from phenyl-pyrazoles and imidacloprid from neo-nicotenoids. The objective of this study was to determine which of these insecticides were most effective against American cockroach.These insecticides were tested for their LC50 values against Periplaneta americana under topical bioassay method, using different concentrations for each chemical.Fipronil 2.5% EC was highly effective at all concentrations applied, while DDVP 50% EC was least toxic amongst all. One way analysis of variance confirmed significant differences between mortality of P. americana and different concentrations applied (P< 0.05.Locality differentiation is an important factor in determining the range of resistance between various localities, as all three localities behaved differently in terms of their levels of resistance.

  4. Immobilizing and lethal effects of spider venoms on the cockroach and the common mealbeetle.

    Science.gov (United States)

    Friedel, T; Nentwig, W

    1989-01-01

    Immobilizing and lethal effects of the venoms obtained from six spider species (Brachypelma albopilosum, Atrax robustus, Cupiennius salei, Selenops mexicanus, Tegenaria atrica, Argiope bruennichi) were tested on Blatta orientalis (cockroach) and Tenebrio molitor (common mealbeetle). The immobilizing effects were quantified by measuring insect locomotor activity in circle arenas observed over 72 hr after venom injection. Both insect species showed cramps, quivering and jerking of the limbs as well as flaccid paralysis after venom injection. Through relative toxicity of the venoms tested is the same in T. molitor and B. orientalis, T. molitor is absolutely less sensitive to spider venoms. The effects on locomotor activity show time characteristics specific for each venom. A dependence of the venom paralyzing effects on insect locomotor activity, low intensity of the initial excitatory phase of the venom effects and partial recovery of the insects was found with A. bruennichi and T. atrica venom. The maximal venom yields of A. bruennichi and S. mexicanus are not lethal to B. orientalis, indicating that the mere immobilizing effects of spider venoms are far more crucial to prey capture than their lethal effects. The contribution of a variety of differently acting neurotoxic components in spider venoms to the observed venom effects on insects and the significance of the venoms in spider nutrition, hunting behaviour and ecology are discussed. PMID:2728023

  5. Structure of tracheae and the functional implications for collapse in the American cockroach.

    Science.gov (United States)

    Webster, Matthew R; Socha, John J; Teresi, Luciano; Nardinocchi, Paola; De Vita, Raffaella

    2015-12-01

    The tracheal tubes of insects are complex and heterogeneous composites with a microstructural organization that affects their function as pumps, valves, or static conduits within the respiratory system. In this study, we examined the microstructure of the primary thoracic tracheae of the American cockroach (Periplaneta americana) using a combination of scanning electron microscopy and light microscopy. The organization of the taenidia, which represents the primary source of structural reinforcement of the tracheae, was analyzed. We found that the taenidia were more disorganized in the regions of highest curvature of the tracheal tube. We also used a simple finite element model to explore the effect of cross-sectional shape and distribution of taenidia on the collapsibility of the tracheae. The eccentricity of the tracheal cross-section had a stronger effect on the collapse properties than did the distribution of taenidia. The combination of the macro-scale geometry, meso-scale heterogeneity, and microscale organization likely enables rhythmic tracheal compression during respiration, ultimately driving oxygen-rich air to cells and tissues throughout the insect body. The material design principles of these natural composites could potentially aid in the development of new bio-inspired microfluidic systems based on the differential collapse of tracheae-like networks.

  6. Characterization of an Invertebrate-Type Dopamine Receptor of the American Cockroach, Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Britta Troppmann

    2014-01-01

    Full Text Available We have isolated a cDNA coding for a putative invertebrate-type dopamine receptor (Peadop2 from P. americana brain by using a PCR-based strategy. The mRNA is present in samples from brain and salivary glands. We analyzed the distribution of the PeaDOP2 receptor protein with specific affinity-purified polyclonal antibodies. On Western blots, PeaDOP2 was detected in protein samples from brain, subesophageal ganglion, thoracic ganglia, and salivary glands. In immunocytochemical experiments, we detected PeaDOP2 in neurons with their somata being located at the anterior edge of the medulla bilaterally innervating the optic lobes and projecting to the ventro-lateral protocerebrum. In order to determine the functional and pharmacological properties of the cloned receptor, we generated a cell line constitutively expressing PeaDOP2. Activation of PeaDOP2-expressing cells with dopamine induced an increase in intracellular cAMP. In contrast, a C-terminally truncated splice variant of this receptor did not exhibit any functional property by itself. The molecular and pharmacological characterization of the first dopamine receptor from P. americana provides the basis for forthcoming studies focusing on the significance of the dopaminergic system in cockroach behavior and physiology.

  7. Tribology in secondary wood machining

    Energy Technology Data Exchange (ETDEWEB)

    Ko, P.L.; Hawthorne, H.M.; Andiappan, J.

    1998-07-01

    Secondary wood manufacturing covers a wide range of products from furniture, cabinets, doors and windows, to musical instruments. Many of these are now mass produced in sophisticated, high speed numerical controlled machines. The performance and the reliability of the tools are key to an efficient and economical manufacturing process as well as to the quality of the finished products. A program concerned with three aspects of tribology of wood machining, namely, tool wear, tool-wood friction characteristics and wood surface quality characterization, was set up in the Integrated Manufacturing Technologies Institute (IMTI) of the National Research Council of Canada. The studies include friction and wear mechanism identification and modeling, wear performance of surface-engineered tool materials, friction-induced vibration and cutting efficiency, and the influence of wear and friction on finished products. This research program underlines the importance of tribology in secondary wood manufacturing and at the same time adds new challenges to tribology research since wood is a complex, heterogeneous, material and its behavior during machining is highly sensitive to the surrounding environments and to the moisture content in the work piece.

  8. Bioelimination of 51Cr and 85Sr by cockroaches, Gromphadorhina portentosa (orthoptera: blaberidae), as affected by mites, Gromphadorholaelaps schaeferi (parasitiformes: laelapidae)

    International Nuclear Information System (INIS)

    The rates of Chromium-51 and Strontium-85 assimilation and bioelimination by the hissing cockroach, Gromphadorhina portentosa (Schaum) are described when the symbiotic mite, Gromphadorholaelaps schaeferi Till, was present or removed. Mite-infested cockroaches had significantly higher rates of 51Cr elimination relative to mite-free cockroaches, implying more rapid gut clearance times. The authors did not find a significant mite effect on 85Sr elimination by the host, but mite effects could have been masked by the apparently unique process of nutrient assimilation and elimination by G. portentosa. Conventional models of radioactive tracer bioelimination predict a rapid initial loss of tracer due to gut clearance, followed by a slower loss due to excretion of assimilated tracer. The results indicated that assimilated 85Sr was eliminated earlier than unassimilated 85Sr, which was lost by defecation

  9. Bioelimination of 51Cr and 85Sr by cockroaches, Gromphadorhina portentosa (Orthoptera: Blaberidae), as affected by mites, Gromphadorholaelaps schaeferi (parasitiformes: laelapidae)

    International Nuclear Information System (INIS)

    This paper describes rates of Chromium-51 and Strontium-85 assimilation and bioelimination by the hissing cockroach, Gromphadorhina portentosa (Schaum), when the symbiotic mite, Gromphadorholaelaps schaeferi Till, was present or removed. Mite-infested cockroaches had significantly higher rates of 51Cr elimination relative to mite-free cockroaches, implying more rapid gut clearance times. We did not find a significant mite effect on 85Sr elimination by the host, but mite effects could have been masked by the apparently unique process of nutrient assimilation and elimination by G. portentosa. Conventional models of radioactive tracer bioelimination predict a rapid initial loss of tracer due to gut clearance, followed by a slower loss due to excretion of assimilated tracer. Our results indicated that assimilated 85Sr was eliminated earlier than unassimilated 85Sr was lost by defecation

  10. wood burns down

    Directory of Open Access Journals (Sweden)

    Vladimir Bukh

    2004-11-01

    Full Text Available To relax the local authorities and to receive the guests of high rank «with no tie» the so-called «Fisherman's House» was built at the source of Angara-river, near Lake Baikal. Vladimir Ivanov, a young architect, was noticed by his skillful performa nee of exclusive orders and became the author of this house. At the time of ferroconcrete boom the proposal to build a wooden guest house turned out to be unexpectedly to the point and was graciously approved. The economic department was entrusted to select the men good for carpenter's work, and the forestry department was entrusted to provide thick round timber. And the work started. But, as it usually happens, the workers did not take the trouble and made the first eight rims of the current timber with an inappropriate diameter.And when Pavlov insisted on demolishing the construction and replacing the logs by the logs with the necessary diameter, the building work obeyed to his will and was finished suecessfully.The architecture of the house is not the derived action of the saw and the fret-saw. It is a technology of the axe. It is natural, convincing and original. It is no use to look for the local sources in it. It grew up in the area of timber and cold winter. And this clear and efficient action kept the construction from the annoying vulgarity and provided Siberian exotics easily penetrating into one's soul, refined as it may be.One of the eminent guests said with admiration: «Even if Pavlov had created nothing more, he would have justified his professional choice with this single house.» Why not to say it as a good toast. However, this is a suitable case to add: style is an absence of style. It is a taste.After the Fisherman's House Irkutsk architects were attracted by wood. They followed the strictness in wood and, as much as they could, created a couple of successful remakes, until the cylinder logs and ... new

  11. The Broad Autism Phenotype Questionnaire

    Science.gov (United States)

    Hurley, Robert S. E.; Losh, Molly; Parlier, Morgan; Reznick, J. Steven; Piven, Joseph

    2007-01-01

    The broad autism phenotype (BAP) is a set of personality and language characteristics that reflect the phenotypic expression of the genetic liability to autism, in non-autistic relatives of autistic individuals. These characteristics are milder but qualitatively similar to the defining features of autism. A new instrument designed to measure the…

  12. Swelling of acetylated wood in organic liquids

    CERN Document Server

    Obataya, E; Obataya, Eiichi; Gril, Joseph

    2005-01-01

    To investigate the affinity of acetylated wood for organic liquids, Yezo spruce wood specimens were acetylated with acetic anhydride, and their swelling in various liquids were compared to those of untreated specimens. The acetylated wood was rapidly and remarkably swollen in aprotic organic liquids such as benzene and toluene in which the untreated wood was swollen only slightly and/or very slowly. On the other hand, the swelling of wood in water, ethylene glycol and alcohols remained unchanged or decreased by the acetylation. Consequently the maximum volume of wood swollen in organic liquids was always larger than that in water. The effect of acetylation on the maximum swollen volume of wood was greater in liquids having smaller solubility parameters. The easier penetration of aprotic organic liquids into the acetylated wood was considered to be due to the scission of hydrogen bonds among the amorphous wood constituents by the substitution of hydroxyl groups with hydrophobic acetyl groups.

  13. Effect of Wood Variables on the Properties of Wood Fiber-Polypropylene Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effect of wood species (Chinese fir and Poplar), wood fiber content (10%, 25%, 40%) and wood fiber sizes (16 to 32 mesh, 32-65 mesh, above 65 mesh) on the properties of the wood fiber-Polypropylene composites were studied in this paper. The results indicate that the effect of wood fiber content and size in composite were more important than that of chosen wood species. Compared with polypropylene without wood fiber, the flexural strength of the composites increased when adding wood fiber into polypr...

  14. Acoustic and adsorption properties of submerged wood

    Science.gov (United States)

    Hilde, Calvin Patrick

    Wood is a common material for the manufacture of many products. Submerged wood, in particular, is used in niche markets, such as the creation of musical instruments. An initial study performed on submerged wood from Ootsa Lake, British Columbia, provided results that showed that the wood was not suitable for musical instruments. This thesis re-examined the submerged wood samples. After allowing the wood to age unabated in a laboratory setting, the wood was retested under the hypothesis that the physical acoustic characteristics would improve. It was shown, however, that the acoustic properties became less adequate after being left to sit. The adsorption properties of the submerged wood were examined to show that the submerged wood had a larger accessible area of wood than that of control wood samples. This implied a lower amount of crystalline area within the submerged wood. From the combined adsorption and acoustic data for the submerged wood, relationships between the moisture content and speed of sound were created and combined with previous research to create a proposed model to describe how the speed of sound varies with temperature, moisture content and the moisture content corresponding to complete hydration of sorption sites within the wood.

  15. Aryl Hydrocarbon Receptor (AhR Modulates Cockroach Allergen-Induced Immune Responses through Active TGFβ1 Release

    Directory of Open Access Journals (Sweden)

    Yufeng Zhou

    2014-01-01

    Full Text Available Background. Aryl hydrocarbon receptor (AhR, a multifunctional regulator that senses and responds to environmental stimuli, plays a role in normal cell development and immune regulation. Recent evidence supports a significant link between environmental exposure and AhR in the development of allergic diseases. We sought to investigate whether AhR plays a role in mediating cockroach allergen-induced allergic immune responses. Methods. AhR expression in human lung fibroblasts from asthmatic and healthy individuals and in cockroach extract (CRE treated human lung fibroblasts (WI-38 was examined. The role of AhR in modulating CRE induced TGFβ1 production was investigated by using AhR agonist, TCDD, antagonist CH122319, and knockdown of AhR. The role of latent TGFβ1 binding protein-1 (LTBP1 in mediating TCDD induced active TGFβ1 release was also examined. Results. AhR expression was higher in airway fibroblasts from asthmatic subjects as compared to healthy controls. AhR in fibroblasts was activated by TCDD with an increased expression of cyp1a1 and cyp1b1. Increased AhR expression was observed in CRE-treated fibroblasts. Importantly, CRE induced TGFβ1 production in fibroblasts was significantly enhanced by TCDD but inhibited by CH122319. Reduced TGFβ1 production was further confirmed in fibroblasts with AhR knockdown. Moreover, AhR knockdown inhibited CRE induced fibroblast differentiation. Furthermore, TCDD induced active TGFβ1 release was significantly inhibited by LTBP1 knockdown. Conclusion. These results provide evidence for the role of AhR in modulating cockroach allergen-induced immune responses through controlling the active TGFβ1 release, suggesting a possible synergistic effect between exposure to allergens and environmental chemicals on the development of allergic diseases.

  16. Cockroaches and flies in mechanical transmission of medical important parasites in Khaldyia Village, El-Fayoum, Governorate, Egypt.

    Science.gov (United States)

    El-Sherbini, Gehad T; Gneidy, Morsy Rateb

    2012-04-01

    The role of non-blood sucking insects in dissemination of human parasites was investigated in Khaldyia Village, Al-Fayoum Governorate over during the summer of 2011. A total of 278 American cockroach (Periplaneta americana), and 508 house flies Musca domestica var. vicina were collected. The insects were collected indoors and outdoors. Flies were abundant in defecation areas and around houses. The recovered zoonotic parasites identified were cysts of Entamoeba histolytica Cryptosporidium parvum and Balantidium coli, and eggs of Ascaris lumbricoides, Anchylostoma deodunale, Enterobius vermicularis, and Trichuris trichura as well as larvae of Strongyloides stercoralis. PMID:22662605

  17. Interface Characteristics of Wood-hybrid Composites

    Institute of Scientific and Technical Information of China (English)

    XUEFenglian; ZHAOGuangjie

    2005-01-01

    In order to understand the current interface characteristics of wood-hybrid composites, this paper starts off from the concept of composite interface and general theory of interface form, then the inner-surface and microstructure of wood and the interface characteristics of composites, such as wood- inorganic, wood-plastic and wood- metal made by electroless plating technique, are concluded and discussed in detail. Meanwhile,on the basis of that, some points of view about how to develop the wood-hybrid composites interface research in the future are also proposed.

  18. WOOD MODIFICATION BY HEAT TREATMENT: A REVIEW

    Directory of Open Access Journals (Sweden)

    Bruno M. Esteves

    2009-02-01

    Full Text Available Wood heat treatment has increased significantly in the last few years and is still growing as an industrial process to improve some wood properties. The first studies on heat treatment investigated mainly equilibrium mois-ture, dimensional stability, durability and mechanical properties. Mass loss, wettability, wood color, and chemical transformations have been subsequently extensively studied, while recent works focus on quality control, modeling, and study the reasons for the improvements. This review explains the recent interest on the heat treatment of wood and synthesizes the major publications on this subject on wood properties, chemical changes, wood uses, and quality control.

  19. Intersegmental coordination of cockroach locomotion: adaptive control of centrally coupled pattern generator circuits

    Directory of Open Access Journals (Sweden)

    Einat eFuchs

    2011-01-01

    Full Text Available Animals’ ability to demonstrate both stereotyped and adaptive locomotor behavior is largely dependent on the interplay between centrally-generated motor patterns and the sensory inputs that shape them. We utilized a combined experimental and theoretical approach to investigate the relative importance of CPG interconnections vs. intersegmental afferents in the cockroach: an animal that is renowned for rapid and stable locomotion. We simultaneously recorded coxal levator and depressor motor neurons (MN in the thoracic ganglia of Periplaneta americana, while sensory feedback was completely blocked or allowed only from one intact stepping leg. In the absence of sensory feedback, we observed a coordination pattern with consistent phase relationship that shares similarities with a double tripod gait, suggesting central, feedforward control. This intersegmental coordination pattern was then reinforced in the presence of sensory feedback from a single stepping leg. Specifically, we report on transient stabilization of phase differences between activity recorded in the middle and hind thoracic MN following individual front-leg steps, suggesting a role for afferent phasic information in the coordination of motor circuits at the different hemiganglia. Data were further analyzed using stochastic models of coupled oscillators and maximum likelihood techniques to estimate underlying physiological parameters, such as uncoupled endogenous frequencies of hemisegmental oscillators and coupling strengths and directions. We found that descending ipsilateral coupling is stronger than ascending coupling, while left-right coupling in both the meso- and meta-thoracic ganglia appear to be symmetrical. We discuss our results in comparison with recent findings in stick insects that share similar neural and body architectures, and argue that the two species may exemplify opposite extremes of a fast-slow locomotion continuum, mediated through different intersegmental

  20. Signaling of pigment-dispersing factor (PDF in the Madeira cockroach Rhyparobia maderae.

    Directory of Open Access Journals (Sweden)

    Hongying Wei

    Full Text Available The insect neuropeptide pigment-dispersing factor (PDF is a functional ortholog of vasoactive intestinal polypeptide, the coupling factor of the mammalian circadian pacemaker. Despite of PDF's importance for synchronized circadian locomotor activity rhythms its signaling is not well understood. We studied PDF signaling in primary cell cultures of the accessory medulla, the circadian pacemaker of the Madeira cockroach. In Ca²⁺ imaging studies four types of PDF-responses were distinguished. In regularly bursting type 1 pacemakers PDF application resulted in dose-dependent long-lasting increases in Ca²⁺ baseline concentration and frequency of oscillating Ca²⁺ transients. Adenylyl cyclase antagonists prevented PDF-responses in type 1 cells, indicating that PDF signaled via elevation of intracellular cAMP levels. In contrast, in type 2 pacemakers PDF transiently raised intracellular Ca²⁺ levels even after blocking adenylyl cyclase activity. In patch clamp experiments the previously characterized types 1-4 could not be identified. Instead, PDF-responses were categorized according to ion channels affected. Application of PDF inhibited outward potassium or inward sodium currents, sometimes in the same neuron. In a comparison of Ca²⁺ imaging and patch clamp experiments we hypothesized that in type 1 cells PDF-dependent rises in cAMP concentrations block primarily outward K⁺ currents. Possibly, this PDF-dependent depolarization underlies PDF-dependent phase advances of pacemakers. Finally, we propose that PDF-dependent concomitant modulation of K⁺ and Na⁺ channels in coupled pacemakers causes ultradian membrane potential oscillations as prerequisite to efficient synchronization via resonance.

  1. Dopamine- and Tyrosine Hydroxylase-Immunoreactive Neurons in the Brain of the American Cockroach, Periplaneta americana

    Science.gov (United States)

    Hamanaka, Yoshitaka; Minoura, Run; Nishino, Hiroshi; Miura, Toru; Mizunami, Makoto

    2016-01-01

    The catecholamine dopamine plays several vital roles in the central nervous system of many species, but its neural mechanisms remain elusive. Detailed neuroanatomical characterization of dopamine neurons is a prerequisite for elucidating dopamine’s actions in the brain. In the present study, we investigated the distribution of dopaminergic neurons in the brain of the American cockroach, Periplaneta americana, using two antisera: 1) an antiserum against dopamine, and 2) an antiserum against tyrosine hydroxylase (TH, an enzyme required for dopamine synthesis), and identified about 250 putatively dopaminergic neurons. The patterns of dopamine- and TH-immunoreactive neurons were strikingly similar, suggesting that both antisera recognize the same sets of “dopaminergic” neurons. The dopamine and TH antibodies intensively or moderately immunolabeled prominent brain neuropils, e.g. the mushroom body (memory center), antennal lobe (first-order olfactory center) and central complex (motor coordination center). All subdivisions of the mushroom body exhibit both dopamine and TH immunoreactivity. Comparison of immunolabeled neurons with those filled by dye injection revealed that a group of immunolabeled neurons with cell bodies near the calyx projects into a distal region of the vertical lobe, which is a plausible site for olfactory memory formation in insects. In the antennal lobe, ordinary glomeruli as well as macroglomeruli exhibit both dopamine and TH immunoreactivity. It is noteworthy that the dopamine antiserum labeled tiny granular structures inside the glomeruli whereas the TH antiserum labeled processes in the marginal regions of the glomeruli, suggesting a different origin. In the central complex, all subdivisions excluding part of the noduli and protocerebral bridge exhibit both dopamine and TH immunoreactivity. These anatomical findings will accelerate our understanding of dopaminergic systems, specifically in neural circuits underlying aversive memory

  2. Stage-dependent tolerance of the German cockroach, Blattella germanica for dichlorvos and propoxur.

    Science.gov (United States)

    Qian, K; Wei, Xq; Zeng, Xp; Liu, T; Gao, Xw

    2010-01-01

    tage-dependent dichlorvos and propoxur tolerance in a field population of the German cockroach, Blattella germanica Linnaeus (Blatodea: Blattellidae), was investigated in the laboratory using a topical application bioassay. The results showed the 6 week-old nymphs were more tolerant to dichlorvos and propoxur than the other ages tested. LD₅₀ values of dichlorvos and propoxur for the 6 week-old nymphs were 2.003 µg per insect and 5.296 µg per insect, respectively. Tolerance ratios of 18.55-fold and 4.98-fold for LD₅₀ were obtained from 6-week-old nymphs compared to 4 week-old nymphs. The specific activity of acetylcholinesterase (AChE) from 1 week-old nymphs was the highest among all tested developmental stages of nymphs and adult males and females. The specific activity of AChE decreased significantly with increasing age. The sensitivity of AChE to dichlorvos was the highest with a k(i) value of 3.12 × 10⁴ mol⁻¹min⁻¹ in the last nymphal stage of B. germanica (about 6 weeks-old). The AChE from 4 week-old nymphs was the most sensitive to propoxur, with the highest k(i) value being 2.63 × 10⁵ mol⁻¹ min⁻¹. These results indicated that the different developmental stages and sexes of B. germanica affected the inhibition of AChE by dichlorvos and propoxur.

  3. Nonlinear cable properties of the giant axon of the cockroach Periplaneta americana.

    Science.gov (United States)

    Segev, I; Parnas, I

    1985-05-01

    The steady state nonlinear properties of the giant axon membrane of the cockroach Periplaneta americana were studied by means of intracellular electrodes. The resistivity of this membrane markedly decreases in response to small subthreshold depolarizations. The specific slope resistance is reduced by twofold at 5 mV depolarization and by a factor of 14 at 20 mV depolarization. As a result, the spatial decay, V(X), of depolarizing potentials is enhanced when compared with the passive (exponential) decay. This enhancement is maximal at a distance of 1-1.5 mm from a point of subthreshold (0-20 mV) depolarizing perturbation. At that distance, the difference between the actual potential and the potential expected in the passive axon is approximately 30%. The effects of membrane rectification on V(X) were analyzed quantitatively with a novel derivation based on Cole's theorem, which enables one to calculate V(X) directly from the input current-voltage (I0-V) relation of a long axon. It is shown that when the experimental I0-V curve is replotted as (I0Rin)-1 against V (where Rin is the input resistance at the resting potential), the integral between any two potentials (V1 greater than V2) on this curve is the distance, in units of the resting space constant, over which V1 attenuates to V2. Excellent agreement was found between the experimental V(X) and the predicted value based solely on the input I0-V relation. The results demonstrate that the rectifying properties of the giant axon membrane must be taken into account when the electrotonic spread of even small subthreshold potentials is studied, and that, in the steady state, this behavior can be extracted from measurements at a single point. The effect of rectification on synaptic efficacy is also discussed.

  4. Multiplex Assay for Protein Profiling and Potency Measurement of German Cockroach Allergen Extracts.

    Directory of Open Access Journals (Sweden)

    Taruna Khurana

    Full Text Available German cockroach (GCr allergens induce IgE responses and may cause asthma. Commercial GCr allergen extracts are variable and existing assays may not be appropriate for determining extract composition and potency.Our aim was to develop a multiplex antibody/bead-based assay for assessment of GCr allergen extracts.Single chain fragment variable (scFv antibodies against GCr were obtained by screening libraries derived from naïve human lymphocytes and hyperimmunized chicken splenocytes and bone marrow. Selected clones were sequenced and characterized by immunoblotting. Eighteen scFv antibodies (17 chicken, 1 human coupled to polystyrene beads were used in this suspension assay; binding of targeted GCr allergens to antibody-coated beads was detected using rabbit antisera against GCr, and against specific allergens rBla g 1, rBla g 2, and rBla g 4. The assay was tested for specificity, accuracy, and precision. Extracts were also compared by IgE competition ELISA.Chicken scFv's generated eight different binding patterns to GCr proteins from 14 to 150 kDa molecular weight. Human scFv's recognized a 100 kDa GCr protein. The multiplex assay was found to be specific and reproducible with intra-assay coefficient of variation (CV of 2.64% and inter-assay CV of 10.0%. Overall potencies of various GCr extracts were calculated using mean logEC50s for eight selected scFvs. Overall potency measures were also analyzed by assessing the contributions to potency of each target.An scFv antibody-based multiplex assay has been developed capable of simultaneously measuring different proteins in a complex mixture, and to determine the potencies and compositions of allergen extracts.

  5. Functional analysis of Scr during embryonic and post-embryonic development in the cockroach, Periplaneta americana.

    Science.gov (United States)

    Hrycaj, Steven; Chesebro, John; Popadić, Aleksandar

    2010-05-01

    The cockroach, Periplaneta americana represents a basal insect lineage that undergoes the ancestral hemimetabolous mode of development. Here, we examine the embryonic and post-embryonic functions of the hox gene Scr in Periplaneta as a way of better understanding the roles of this gene in the evolution of insect body plans. During embryogenesis, Scr function is strictly limited to the head with no role in the prothorax. This indicates that the ancestral embryonic function of Scr was likely restricted to the head, and that the posterior expansion of expression in the T1 legs may have preceded any apparent gain of function during evolution. In addition, Scr plays a pivotal role in the formation of the dorsal ridge, a structure that separates the head and thorax in all insects. This is evidenced by the presence of a supernumerary segment that occurs between the labial and T1 segments of RNAiScr first nymphs and is attributed to an alteration in engrailed (en) expression. The fact that similar Scr phenotypes are observed in Tribolium but not in Drosophila or Oncopeltus reveals the presence of lineage-specific variation in the genetic architecture that controls the formation of the dorsal ridge. In direct contrast to the embryonic roles, Scr has no function in the head region during post-embryogenesis in Periplaneta, and instead, strictly acts to provide identity to the T1 segment. Furthermore, the strongest Periplaneta RNAiScr phenotypes develop ectopic wing-like tissue that originates from the posterior region of the prothoracic segment. This finding provides a novel insight into the current debate on the morphological origin of insect wings.

  6. Broad Diphotons from Narrow States

    CERN Document Server

    An, Haipeng; Zhang, Yue

    2015-01-01

    ATLAS and CMS have each reported a modest diphoton excess consistent with the decay of a broad resonance at ~ 750 GeV. We show how this signal can arise in a weakly coupled theory comprised solely of narrow width particles. In particular, if the decaying particle is produced off-shell, then the associated diphoton resonance will have a broad, adjustable width. We present simplified models which explain the diphoton excess through the three-body decay of a scalar or fermion. Our minimal ultraviolet completion is a weakly coupled and renormalizable theory of a singlet scalar plus a heavy vector-like quark and lepton. The smoking gun of this mechanism is an asymmetric diphoton peak recoiling against missing transverse energy, jets, or leptons.

  7. Cochlear microphonic broad tuning curves

    Science.gov (United States)

    Ayat, Mohammad; Teal, Paul D.; Searchfield, Grant D.; Razali, Najwani

    2015-12-01

    It is known that the cochlear microphonic voltage exhibits much broader tuning than does the basilar membrane motion. The most commonly used explanation for this is that when an electrode is inserted at a particular point inside the scala media, the microphonic potentials of neighbouring hair cells have different phases, leading to cancelation at the electrodes location. In situ recording of functioning outer hair cells (OHCs) for investigating this hypothesis is exceptionally difficult. Therefore, to investigate the discrepancy between the tuning curves of the basilar membrane and those of the cochlear microphonic, and the effect of phase cancellation of adjacent hair cells on the broadness of the cochlear microphonic tuning curves, we use an electromechanical model of the cochlea to devise an experiment. We explore the effect of adjacent hair cells (i.e., longitudinal phase cancellation) on the broadness of the cochlear microphonic tuning curves in different locations. The results of the experiment indicate that active longitudinal coupling (i.e., coupling with active adjacent outer hair cells) only slightly changes the broadness of the CM tuning curves. The results also demonstrate that there is a π phase difference between the potentials produced by the hair bundle and the soma near the place associated with the characteristic frequency based on place-frequency maps (i.e., the best place). We suggest that the transversal phase cancellation (caused by the phase difference between the hair bundle and the soma) plays a far more important role than longitudinal phase cancellation in the broadness of the cochlear microphonic tuning curves. Moreover, by increasing the modelled longitudinal resistance resulting the cochlear microphonic curves exhibiting sharper tuning. The results of the simulations suggest that the passive network of the organ of Corti determines the phase difference between the hair bundle and soma, and hence determines the sharpness of the

  8. FLEXURAL FATIGUE OF LAMINATED WOOD

    Directory of Open Access Journals (Sweden)

    B. A. Bondarev

    2010-12-01

    Full Text Available Problem statement. Local damage accumulation in goods and construction elements ultimately leading to a failure occurs due to fluctuating load effect. Results and conclusions. The results of the analysis of the experimentally obtained analytical dependences of strength characteristics and resistance to cracks of profiled laminated wood during bending in products and designs are presented. This products and designs operate under static and cyclic loading. Stresses under which cracks form in pilot samples are established from the results, as well as maximum permissible lengths of cracks for static and cyclic load. Effect of natural and technological defects of laminated wood is taken into account. Recommendation on application of laminated wood in products and designs which experience force cyclic loading under operation are given.

  9. Fuel wood symposium; Symposium Energieholz

    Energy Technology Data Exchange (ETDEWEB)

    Wild, C.; Wauer, A. (comps.)

    2001-07-01

    The Bavarian State Institute of Forestry (LWF) organised a 'Fuel Wood Symposium' in Freising-Weihenstephan on 17.11.2000. The purpose of this specialist conference was to give an overview of the use of biomass, especially wood, as an source of energy. (orig.) [German] Die Bayerische Landesanstalt fuer Wald und Forstwirtschaft richtete am 17.11.2000 in Freising-Weihenstephan das 'Symposium Energieholz' aus. Ziel der Fachtagung war es, einen Ueberblick ueber die energetische Nutzung von Biomasse, insbesondere Holz, zu geben. (orig.)

  10. Composite structure of wood cells in petrified wood

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Jakub [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Florek, Marek [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Kwiatek, Wojciech [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Lekki, Janusz [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Chevallier, Pierre [LPS, CEN Saclay et LURE, Universite Paris-Sud, Bat 209D, F-91405 Orsay (France); Zieba, Emil [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Mestres, Narcis [Institut de Ciencia de Materials de Barcelona (ICMAB), Campus de la UAB, E-08193-Bellaterra (Spain); Dutkiewicz, E.M. [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Kuczumow, Andrzej [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland)

    2005-04-28

    Special kinds of petrified wood of complex structure were investigated. All the samples were composed of at least two different inorganic substances. The original cell structure was preserved in each case. The remnants of the original biological material were detected in some locations, especially in the cell walls. The complex inorganic structure was superimposed on the remnant organic network. The first inorganic component was located in the lumena (l.) of the cells while another one in the walls (w.) of the cells. The investigated arrangements were as follows: calcite (l.)-goethite-hematite (w.)-wood from Dunarobba, Italy; pyrite (l.)-calcite (w.)-wood from Lukow, Poland; goethite (l.)-silica (w.)-wood from Kwaczala, Poland. The inorganic composition was analysed and spatially located by the use of three spectral methods: electron microprobe, X-ray synchrotron-based microprobe, {mu}-PIXE microprobe. The accurate mappings presenting 2D distribution of the chemical species were presented for each case. Trace elements were detected and correlated with the distribution of the main elements. In addition, the identification of phases was done by the use of {mu}-Raman and {mu}-XRD techniques for selected and representative points. The possible mechanisms of the described arrangements are considered. The potential synthesis of similar structures and their possible applications are suggested.

  11. Review on Wood Discoloration and its Control

    Institute of Scientific and Technical Information of China (English)

    JIANG Zehui; LV Wenhua; FEI Benhua; REN Haiqing; WU Yuzhang

    2006-01-01

    This paper reviews the mechanisms,types, compositions, affecting factors,prevention and remediable treatments of wood discoloration, and especially puts forward the biological control against wood stain and wood induced coloration.The authors think the followings are important:1)Developing the low poisonous or non-toxic, high-efficient and multi-functional anti-stain chemicals is still an important research direction to control wood discoloration.2)It is still very necessary to remove wood stain and restore wood original color and commercial value.3)The biological control has little environmental pollution and its cost is low.Researches on its theories and application should be strengthened.4)Wood color can be induced and turned to be the needed through heat treatment or ultraviolet irradiation without coloring materials,i.e.induced coloration,is a good idea to modulate wood,bamboo or rattan cane color.Itis becoming a new study field.

  12. SYNERGISTIC WOOD PRESERVATIVES FOR REPLACEMENT OF CCA

    Science.gov (United States)

    The objective of this project was to evaluate the potential synergistic combinations of environmentally-safe biocides as wood preservatives. These wood preservatives could be potential replacements for the heavy-metal based CCA.Didecyldimethylammonium chloride [DDAC] was...

  13. Efficacy of synthetic pyrethroid and propoxur aerosol in the control of German cockroaches (Dictyoptera: Blatellidae in cookhouses

    Directory of Open Access Journals (Sweden)

    V.K. Agrawal, Rina Tilak , K.K. Dutta Gupta

    2005-09-01

    Full Text Available Background & objectives: A field trial was carried out in cookhouses in an urban area to evaluate theefficacy of synthetic pyrethroid (0.02% deltamethrin + 0.13% allethrin and propoxur aerosols (2% inthe control of German cockroaches (Blatella germanica.Methods: A total of six cookhouses were selected by simple random sampling method (two each forthe two insecticide treatments and two for control.Results: It was observed that 89.36–87.8 and 77.95–59.74% reductions were achieved with propoxurand synthetic pyrethroid treatment respectively by first week post-treatment. The reduction in propoxurtreated areas by eight weeks post-treatment was 82.98–76.13%, whereas the reduction in thesame time period in synthetic pyrethroid treated areas ranged from 14.36% to an increase in density bya phenomenal 157.86% in one of the treated sites.Interpretation & conclusion: The study reports the efficacy of propoxur aerosol (2% treatment oversynthetic pyrethroid (0.02% deltamethrin + 0.13% allethrin in the control of cockroach infestation incookhouses in urban area.

  14. Novel point mutations in the German cockroach para sodium channel gene are associated with knockdown resistance (kdr) to pyrethroid insecticides.

    Science.gov (United States)

    Liu, Z; Valles, S M; Dong, K

    2000-10-01

    Knockdown resistance (kdr) to pyrethroid insecticides has been attributed to point mutations in the para sodium channel gene in more than a half dozen insect pest species. In this study, we identified two novel para mutations in five highly resistant kdr-type German cockroach strains. The two mutations, from glutamic acid (E434) to lysine (K434) and from cysteine (C764) to arginine (R764), respectively, are located in the first intracellular linker connecting domains I and II. E434K is located near the beginning of the linker (closest to domain I), whereas C764R is found toward the end of the linker (closest to domain II). Two additional mutations from aspartic acid (D58) to glycine (G58), and from proline (P1880) to leucine (L1888), respectively, were found in one of the resistant strains. The four mutations coexist with the previously identified leucine to phenylalanine (L993F) kdr mutation in IIS6, and are present only in the highly resistant individuals of a given strain. These findings suggest that these mutations might be responsible for high levels of knockdown resistance toward pyrethroid insecticides in the German cockroach. PMID:10899465

  15. Body of Wood

    Directory of Open Access Journals (Sweden)

    Pierre Michon

    2014-12-01

    not only a defrocked friar with the guys or on the street; he donned the silk babouches when he went home too. He dispossessed himself of the Seine that rolled on before his eyes; the small girl who lived on her feet, whom he puts to death in all his books, he hardly saw her; the loveliest girls of his day, the finest too for sure, who wanted him, so that he happened to come – he dispossessed himself of them, whether he came or opted to come no more, which amounted to the same thing; no apples from Norman orchards, no trees deep in the woods, no unlaced Louise Colet, no lilies, no young laughter, no Louise Colet weeping at his door, he kissed it all off, laughed over it and kissed it off, cried about it and kissed it off, he was not there. In fact he had nothing, he was deprived of everything, since it was in his head.

  16. Potential adverse health effects of wood smoke.

    OpenAIRE

    Pierson, W E; Koenig, J Q; Bardana, E J

    1989-01-01

    The use of wood stoves has increased greatly in the past decade, causing concern in many communities about the health effects of wood smoke. Wood smoke is known to contain such compounds as carbon monoxide, nitrogen oxides, sulfur oxides, aldehydes, polycyclic aromatic hydrocarbons, and fine respirable particulate matter. All of these have been shown to cause deleterious physiologic responses in laboratory studies in humans. Some compounds found in wood smoke--benzo[a]pyrene and formaldehyde-...

  17. Use of nanofillers in wood coatings

    DEFF Research Database (Denmark)

    Nikolic, Miroslav; Lawther, John Mark; Sanadi, Anand Ramesh

    2015-01-01

    Wood has been used for thousands of years and remains an important material in the construction industry, most often protected with coatings. Development of nanotechnology allows further improvements or new performance properties to be achieved in wood coatings. Increased UV protection...... like a low level of loading, have already established nanoparticles in some areas of wood coatings. This article is a comprehensive scientific review of the published work in the use of nanofillers in wood coatings....

  18. Brazilian sawn wood price and income elasticity

    OpenAIRE

    Rommel Noce; José Luiz Pereira de Rezende; Agostinho Lopes de Souza; Lourival Marin Mendes; Márcio Lopes; Rosa Maria Miranda Armond Carvalho; Juliana Mendes de Oliveira; Juliana Lorensi do Canto

    2010-01-01

    This study estimated the sawn wood demand price and income elasticity. Specifically it was estimated the priceelasticity of sawn wood, the cross price elasticity of wood panels and the income elasticity of Brazilian GDP. A log-log model withcorrection through outline of the mobile average (MA(1)) was used, adjusted for the period of 1971 to 2006, which showed to bestable, with satisfactory significance levels. It was observed that sawn wood demand is inelastic in relation to price and elastic...

  19. Efficacy of killing cockroaches with smoke in three different kitchens%烟剂对厨房蟑螂的灭效研究

    Institute of Scientific and Technical Information of China (English)

    李卫鹏; 任兴联; 宋谦; 胡和文

    2011-01-01

    目的 观察15%优士B型乳油烟剂现场灭蟑效果及影响因素.方法 现场实验观察.结果 15%优士B型乳油1∶20、1∶15、1∶10 3种稀释药液烟剂对连队、幼儿园、宾馆的厨房进行熏杀,均可以在短时间内迅速降低蟑螂密度.结论 15%优士B型乳油烟剂熏杀灭蟑效果好,影响因素较小,具有推广应用价值.%Objective To observe the efficacy of killing cockroaches on spot with 15% Youshi B missible oil smoke.Methods Experiment observing on spot.Results To kill cockroaches in company, kindergarten and hotel kitchen with 1:20,1: 15,1:10 three different diluted 15% Youshi B missible oil smoke,it could decrease the density of cockroaches rapidly in a little time.Conclusion It is an efficacy method to kill cockroaches with 15% Youshi B missible oil smoke.It is good enough to kill cockroaehes in large areas with airtight space.

  20. Pyrotag sequencing of the gut microbiota of the cockroach Shelfordella lateralis reveals a highly dynamic core but only limited effects of diet on community structure.

    Directory of Open Access Journals (Sweden)

    Christine Schauer

    Full Text Available Although blattid cockroaches and termites share a common ancestor, their diets are distinctly different. While termites consume a highly specialized diet of lignocellulose, cockroaches are omnivorous and opportunistic feeders. The role of the termite gut microbiota has been studied intensively, but little is known about the cockroach gut microbiota and its function in digestion and nutrition, particularly the adaptation to different diets. Our analyses of the bacterial gut microbiota of the blattid cockroach Shelfordella lateralis combining terminal restriction fragment length polymorphism of their 16S rRNA genes with physiological parameters (microbial metabolites, hydrogen and methane emission indicated substantial variation between individuals but failed to identify any diet-related response. Subsequent deep-sequencing of the 16S rRNA genes of the colonic gut microbiota of S. lateralis fed either a high- or a low-fiber diet confirmed the absence of bacterial taxa that responded to diet. Instead, we found a small number of abundant phylotypes that were consistently present in all samples and made up half of the community in both diet groups. They varied strongly in abundance between individual samples at the genus but not at the family level. The remaining phylotypes were inconsistently present among replicate batches. Our findings suggest that S. lateralis harbors a highly dynamic core gut microbiota that is maintained even after fundamental dietary shifts, and that any dietary effects on the gut community are likely to be masked by strong individual variations.

  1. Toxicity of Pyrethroid and Organophosphorous Insecticides against Two Field Collected Strains of the German Cockroach Blattella Germanica (Blattaria: Blattellidae from Hospitals in Hamadan, Iran

    Directory of Open Access Journals (Sweden)

    Mojtaba Limoee

    2012-12-01

    Full Text Available Background: The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for path­ogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos against two hospital- collected strains of the German cockroach was investigated.Methods: Topical bioassay methods were carried out for detecting insecticide susceptibility of adult male cock­roaches. For each insecticide, four to six concentrations resulting in >0% and <100% mortality were used. Three to six replicates of 10 cockroaches per concentration were conducted. The differences between LD50 (µg/g values were considered statistically significant only when the 95% confidence intervals did not overlap.Results: Two hospital- collected strains of the German cockroach showed low to moderate levels of resistance to chlorpyrifos, permethrin, malathion and cypermethrin based on resistance ratios compared with susceptible strain.Conclusion: The low level chlorpyrifos resistance suggesting this insecticide may still provide adequate control of these strains. While the obsereved moderate levels of resistance to cypermethrin could imply developing resistance to this compound.

  2. Look at That!: Using Madagascar Hissing Cockroaches to Develop and Enhance the Scientific Inquiry Skill of Observation in Middle School Students

    Science.gov (United States)

    Wagler, Ron

    2011-01-01

    Middle school students can develop and enhance their observation skills by participating in teacher-guided scientific inquiry (NRC 1996) activities where they observe animals that tend to act in known, predictable ways. Madagascar hissing cockroaches ("Gromphadorhina portentosa") are one such animal. This article presents beginning, intermediate,…

  3. Genome size of termites (Insecta, Dictyoptera, Isoptera) and wood roaches (Insecta, Dictyoptera, Cryptocercidae)

    Science.gov (United States)

    Koshikawa, Shigeyuki; Miyazaki, Satoshi; Cornette, Richard; Matsumoto, Tadao; Miura, Toru

    2008-09-01

    The evolution of genome size has been discussed in relation to the evolution of various biological traits. In the present study, the genome sizes of 22 dictyopteran species were estimated by Feulgen image analysis densitometry and 6-diamidino-2-phenylindole (DAPI)-based flow cytometry. The haploid genome sizes ( C-values) of termites (Isoptera) ranged from 0.58 to 1.90 pg, and those of Cryptocercus wood roaches (Cryptocercidae) were 1.16 to 1.32 pg. Compared to known values of other cockroaches (Blattaria) and mantids (Mantodea), these values are low. A relatively small genome size appears to be a (syn)apomorphy of Isoptera + Cryptocercus, together with their sociality. In some phylogenetic groups, genome size evolution is thought to be influenced by selective pressure on a particular trait, such as cell size or rate of development. The present results raise the possibility that genome size is influenced by selective pressures on traits associated with the evolution of sociality.

  4. Sustainable wood waste management in Nigeria

    Directory of Open Access Journals (Sweden)

    Owoyemi Jacob Mayowa

    2016-09-01

    Full Text Available Wood industries produce large volumes of residues which must be utilized, marketed or properly disposed of. Heaps of wood residues are common features in wood industries throughout the year. In Nigeria, this residue is generally regarded as waste and this has led to open burning practices, dumping in water bodies or dumping in an open area which constitutes environmental pollution. Sawmills in Nigeria generated over 1,000,000 m3 of wood waste in 2010 while about 5000 m3 of waste was generated in plywood mills. Nigeria generates about 1.8 million tons of sawdust annually and 5.2 million tons of wood wastes. The impact of improper disposal of waste wood on the environment affects both the aquatic and terrestrial ecosystems. Also burning of waste wood releases greenhouse gases into the atmosphere causing various health issues. Reuse/recycling of these wood residues in Nigeria will reduce the pressure on our ever decreasing forests, reduce environmental pollution, create wealth and employment. The literature available on this subject was reviewed and this article, therefore, focuses on the various methods of wood waste disposal and its utilization in Nigerian wood industries, the effects of wood waste on the environment as well as on human health and the benefits of proper wood waste management practices.

  5. WOOD COLOR CHANGES BY AMMONIA FUMING

    Directory of Open Access Journals (Sweden)

    Josip Miklečić,

    2012-06-01

    Full Text Available This paper studies the influence of ammonia gas on wood color changes in response to an increasing demand for dark colored wood specimens. The darker wood color in ammonia fuming is accomplished through chemical reactions between ammonia gas and wood compounds. We exposed oak, maple, spruce, and larch wood samples to ammonia gas for 16 days. During fuming, the color changes were studied using CIE L*a*b* parameters. After fuming, the changes in extractives content, tannin, and nitrogen content were analyzed. The chemical changes of wood and residues of wood extractives after fuming were analyzed by FTIR spectroscopy. Oak wood reacted intensively with ammonia gas in a very short time, and the darkening was prominent for all the investigated wood species. It was established that tannin had no major influence on color changes of maple and larch wood in the ammonia-fuming process. The FTIR spectra of fumed wood indicated involvement of carbonyl groups, and the FTIR spectra of wood extractives indicated involvement of carbonyl, aromatic, and alcohol groups in reaction with ammonia gas.

  6. Wood science professor honored by international academy

    OpenAIRE

    Davis, Lynn

    2009-01-01

    Audrey Zink-Sharp, a wood science and forest products professor in Virginia Tech's College of Natural Resources, has been elected a Fellow of the International Academy of Wood Science (IAWS), a non-profit assembly of scientists representing all facets of wood science.

  7. Wood and concrete polymer composites

    International Nuclear Information System (INIS)

    There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

  8. Wood quality of white willow

    Directory of Open Access Journals (Sweden)

    André Leclercq

    1997-01-01

    Full Text Available Based upon an exhaustive work made by Sacré (1974 and a review of the literature sine 1960, the author gathered together the anatomical, physical and mechanical characteristics, the machining behaviour (industrial sawing, planing, surfacing, shaping, mortising and nailing and wood end-uses of white willow.

  9. Wood quality of white willow

    OpenAIRE

    André Leclercq

    1997-01-01

    Based upon an exhaustive work made by Sacré (1974) and a review of the literature sine 1960, the author gathered together the anatomical, physical and mechanical characteristics, the machining behaviour (industrial sawing, planing, surfacing, shaping, mortising and nailing) and wood end-uses of white willow.

  10. Mathematical Simulation of Temperature Profiles within Microwave Heated Wood Made for Wood-Based Nanocomposites

    OpenAIRE

    Xianjun Li; Yongfeng Luo; Hongbin Chen; Xia He; Jianxiong Lv; Yiqiang Wu

    2013-01-01

    High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nanocomposites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased al...

  11. Meeting China’s Demands for Imported Wood and Wood Fibre

    OpenAIRE

    Midgley, Stephen

    2005-01-01

    China has developed a large, flourishing and rapidly modernising wood and wood fibre industry. China consumes an estimated 365 million m3 (roundwood equivalent) of wood and wood fibre annually and relies heavily upon imports. These imports increased nearly 10-fold between 1996 and 2004 to 106 million m3, making China the world’s largest importer of forest and wood products. As China enjoys substantial economic growth, buoyant housing construction and improving living standards, it is likely t...

  12. Wood Microstructure Effects on Chinese White Poplar Dyeing

    Institute of Scientific and Technical Information of China (English)

    DUANXinfang; BAOFucheng

    2004-01-01

    In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tornentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures,and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6-0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese whitep oplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation.

  13. Antenna contact and agonism in the male lobster cockroach, Nauphoeta cinerea.

    Science.gov (United States)

    Chou, Szu-Ying; Huang, Zachary Y; Chen, Shu-Chun; Yang, Rou-Ling; Kou, Rong

    2007-08-01

    On any given day, about 35% of 80- to 85-day-old socially naïve male (SNM) lobster cockroaches (Nauphoeta cinerea) spontaneously adopted an aggressive posture (AP) without encountering another male [spontaneous AP (SAP)]. Although SAP SNMs showed significantly higher release of the pheromone 3-hydroxy-2-butanone (3H-2B) than non-SAP SNMs, there was no significant difference in hemolymph juvenile hormone (JH) III titer. When different body parts were tested for induction of the attack behavior, the antenna was found to be the most effective. After 1 min of contact with an antenna from another SAP SNM, attack behavior was induced in 100% of SAP and 76.2% of non-SAP SNMs, and the JH III titer was significantly increased in all responders. Among the non-SAP SNMs, the JH III titer before antenna contact was significantly lower in the non-responders than in the responders, and, although the JH III increase induced by 1 min antenna contact was similar between responders and non-responders, the final JH III titer of the non-responders was significantly lower. A similar attack response, JH III titer change, and 3H-2B release were seen when the individual's own antenna was used. After 5 min of contact with an antenna from another SAP SNM, attack behavior was induced in 100% of SAP and 82% of non-SAP SNMs; in the former, 3H-2B release was similar before and after antenna contact, but the JH III titer was significantly increased after antenna contact, while, in the latter, both 3H-2B release and JH III titer were significantly increased after antenna contact. Among the non-SAP SNMs, JH III titer in the non-responders was not elevated after 5 min antenna contact, and was significantly lower than that in the responders. A pentane-washed antenna did not induce attack behavior or increase the hemolymph JH III titer, and a pentane-washed antenna coated with 3H-2B also failed to induce attack behavior. These results indicate that N. cinerea male-male agonistic interactions, to

  14. Ghost imaging with broad distance

    Institute of Scientific and Technical Information of China (English)

    段德洋; 张路; 杜少将; 夏云杰

    2015-01-01

    We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is.

  15. Potential adverse health effects of wood smoke

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, W.E.; Koenig, J.Q.; Bardana, E.J. Jr.

    1989-09-01

    The use of wood stoves has increased greatly in the past decade, causing concern in many communities about the health effects of wood smoke. Wood smoke is known to contain such compounds as carbon monoxide, nitrogen oxides, sulfur oxides, aldehydes, polycyclic aromatic hydrocarbons, and fine respirable particulate matter. All of these have been shown to cause deleterious physiologic responses in laboratory studies in humans. Some compounds found in wood smoke--benzo(a)pyrene and formaldehyde--are possible human carcinogens. Fine particulate matter has been associated with decreased pulmonary function in children and with increased chronic lung disease in Nepal, where exposure to very high amounts of wood smoke occurs in residences. Wood smoke fumes, taken from both outdoor and indoor samples, have shown mutagenic activity in short-term bioassay tests. Because of the potential health effects of wood smoke, exposure to this source of air pollution should be minimal.29 references.

  16. Potential adverse health effects of wood smoke.

    Science.gov (United States)

    Pierson, W E; Koenig, J Q; Bardana, E J

    1989-09-01

    The use of wood stoves has increased greatly in the past decade, causing concern in many communities about the health effects of wood smoke. Wood smoke is known to contain such compounds as carbon monoxide, nitrogen oxides, sulfur oxides, aldehydes, polycyclic aromatic hydrocarbons, and fine respirable particulate matter. All of these have been shown to cause deleterious physiologic responses in laboratory studies in humans. Some compounds found in wood smoke--benzo[a]pyrene and formaldehyde--are possible human carcinogens. Fine particulate matter has been associated with decreased pulmonary function in children and with increased chronic lung disease in Nepal, where exposure to very high amounts of wood smoke occurs in residences. Wood smoke fumes, taken from both outdoor and indoor samples, have shown mutagenic activity in short-term bioassay tests. Because of the potential health effects of wood smoke, exposure to this source of air pollution should be minimal. PMID:2686171

  17. Influence of wood structure on wood properties of tropical species

    OpenAIRE

    Baar, Jan

    2014-01-01

    The presented thesis is focused on aesthetical and acoustic properties of tropical wood. The discussed tropical species are utilized in Europe mainly for their unusual appearance and colour in joinery and furniture production. The irreplacable acoustic properties like low internal friction predestine specific species for production of musical instruments. The colour of six selected tropical species - jatoba (Hymenea courbaril L.), massaranduba (Manilkara bidentata A. Chev.), muiracatiara (Ast...

  18. 动车组列车蟑螂种群分布及生态习性的研究%Investigation of EMU cockroach population distribution and ecological habits

    Institute of Scientific and Technical Information of China (English)

    迟丹; 迟淞元; 薛文根; 刘晓闪

    2012-01-01

    Objective To find out the population distribution and habits of EMU train cockroaches,and provide scientific basis for preventing and controlling the EMU train cockroaches. Methods House sticky cockroach recapture method, tracking and observing the activities of the cockroaches. Results The cockroaches on the EMU main mostly were German cockroach. Cockroaches density index; after the waste box > after water machine > distribution room > under bar counter > spare parts storage > bathroom > storage room; treatment medicine under 90 cm, the percentage of eating by stealth was 81. 11%. Conclusion EMU cockroaches mainly distributed after the waste box, the water machine,the power distribution room and so on, the main habitat venues of cockroaches where height is less than 90 cm. The activity patterns are basically the same with the cockroaches in other places. Boarding way of the cockroaches are mainly the following four kinds; the sale of food on the dining car cargo, passengers line package, train preparedness personnel, crew members%目的 摸清动车组列车蟑螂种群分布及生态习性,为动车组列车蟑螂防治提供科学依据.方法 蟑螂屋粘捕法,跟踪观察蟑螂活动情况.结果 动车组列车蟑螂种类主要为德国小蠊,蟑螂密度指数:废物箱后>饮水机后>配电室>吧台下>备品间>卫生间>储藏间;施药90 cm以下高度盗食率为81.11%.结论 动车组列车蟑螂主要分布于废物箱后、饮水机后、配电室等部位,90 cm以下高度是蟑螂主要栖息及活动场所;其活动规律与其他场所蟑螂基本相同.蟑螂主要是餐车出售食品上货时带入,旅客行包带入,列车整备人员带入,乘务人员带人4种途径.

  19. Mathematical Simulation of Temperature Profiles within Microwave Heated Wood Made for Wood-Based Nano composites

    International Nuclear Information System (INIS)

    High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nano composites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased along the direction of microwave transmission when the unilateral microwave heating was applied, and the temperature difference along the thickness direction of wood was very significant; The temperature with wood firstly increased and then gradually decreased from the wood surface to interior when the bilateral microwave heating was applied. Compared with the unilateral microwave heating, bilateral microwave heating is a better microwave heating method for the more uniform wood microwave pretreatment.

  20. 郑州市蟑螂种群密度及侵害情况的调查研究%Investigation on cockroach density and infestation in Zhengzhou city

    Institute of Scientific and Technical Information of China (English)

    袁中良; 王广州; 王志刚; 韩曲波

    2011-01-01

    目的 了解郑州市蟑螂种群密度和侵害情况,为蟑螂防治提供科学依据.方法 采用粘捕法对郑州市三区监测点进行蟑螂侵害、密度情况调查.结果 在各类环境共捕获蟑螂3 843只,平均侵害率为16.66%,密度为2.33只/张.德国小蠊占98.41%,为优势种群.结论 德国小蠊为优势种群,餐饮业、宾馆、农贸市场、浴池密度较高.应采取综合防治措施,有效降低蟑螂侵害率,控制蟑螂密度.%Objective To understand the infestation and density of cockroach, and provide scientific basis for killing cockroach in Zhengzhou city. Methods Using sticky traps to investigate cockroach infestation and density situation at three test points. Results Totally 3 843 cockroaches were caught in different environments in Zhengzhou city in 2010. The average infestation rate reached 16. 66%. The average index of density was 2. 33 pieces. Blattella germanica(9&. 41% ) was the dominant species in various environments. Conclusion Blattella germanica is the dominant species in various environment. There are high density of cockroaches in catering trades, hotel, agricultural market and public baths. It is necessary to take comprehensive control measures and strengthen the technical training to prevent and control cockroaches. Using drugs rationally so as to reduce the infestation rate of cockroaches and control the density of cockroaches effectively.

  1. Wood energy and air quality

    International Nuclear Information System (INIS)

    This publication first recalls the main benefits of the use of wood, the first source of renewable energy in France: abundant and local resource, low CO2 emission, competitiveness, job creation. It comments the relationship between the use of this source of energy and the compliance with air quality standards as they are notably defined by European directives, as the use of wood as heating source is one of the recommended lever to improve air quality. The publication comments emissions generated by this type of heating (mainly in the housing sector, with some critical meteorological periods). Levers for actions are discussed: fleet renewal to promote the best performing equipment, practice improvements (fuel quality, apparatus maintenance). Actions undertaken by the ADEME are briefly reviewed: support to individual equipment fleet modernisation, support to R and D, support to the sector, and information and communication

  2. FLEXURAL FATIGUE OF LAMINATED WOOD

    OpenAIRE

    B. A. Bondarev; S. V. Povetkin

    2010-01-01

    Problem statement. Local damage accumulation in goods and construction elements ultimately leading to a failure occurs due to fluctuating load effect. Results and conclusions. The results of the analysis of the experimentally obtained analytical dependences of strength characteristics and resistance to cracks of profiled laminated wood during bending in products and designs are presented. This products and designs operate under static and cyclic loading. Stresses under which cracks form in pi...

  3. Hypermedia in the Ambient Wood

    OpenAIRE

    Weal, Mark J; Michaelides, Danius T.; Thompson, Mark K.; De Roure, David C

    2003-01-01

    The Ambient Wood project, carried out as part of the Equator IRC, set out to provide an augmented learning experience for children in an outdoor environment. Using a variety of devices, the children gathered information about the woodland habitats performing basic scientific enquiry and hypothesis testing. In this paper we describe the supporting information infrastructure used in the project, focusing on how hypermedia tools and techniques were used to structure and deliver the information t...

  4. Carbon sequestration via wood burial

    OpenAIRE

    Zeng Ning

    2008-01-01

    Abstract To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux...

  5. Production of wood derived fuels. Review of research projects; Puupolttoaineiden tuotantotekniikka. Tutkimusalueen katsaus

    Energy Technology Data Exchange (ETDEWEB)

    Korpilahti, A. [Metsaeteho Oy, Helsinki (Finland)

    1997-12-01

    The research and development work was very active on the area of wood derived fuels during the past year 1996. Totally some 40 projects were going on, and till the end of the year about 15 projects were completed. The projects broadly covered the research area focusing from material flows, productivity studies, basic wood properties to several case studies. When new production methods and machinery was introduced earlier by demonstration projects, now they were investigated by follow up projects. The economical and quality results of logging residue harvesting and comminution seem quite satisfactory, but integrated methods and production chains still need research and development. (orig.)

  6. Nonisothermal moisture movement in wood

    Institute of Scientific and Technical Information of China (English)

    LI Xianjun; ZHANG Biguang; LI Wenjun; LI Yanjun

    2006-01-01

    In order to analyze the effect of temperature gradient on moisture movement during highly intensive drying,such as microwave-vacuum drying,the profile of the temperature and moisture content in sealed wood whose opposite faces were subjected to temperature gradient for a short time was measured.The ratio of the moisture content (MC) gradient to the temperature gradient (dM/dT) was calculated and the factors influencing moisture movement under nonisothermal conditions were discussed.The results indicate that moisture moved in wood from the warm surface to the cold one even if opposite faces of the sealed wood assembly were exposed continuously to different but constant temperatures for a short period.The moisture content on the cold surface was higher than that on the warm surface.The moisture content gradient opposite to the temperature gradient was established,and the dM/dT was below 0.9%/℃.The temperature in the sample and the distance from the hot surface of the sample was strongly linearly correlated.With an increase in temperature,initial moisture content and experimental time,the dM/dT was significantly increased.

  7. Perception of Wood in River Channels

    Science.gov (United States)

    Chin, A.

    2003-12-01

    In managing river channels, wood is often perceived as hazardous and has traditionally been removed. On the other hand, wood provides many benefits including food and habitat for fish and mechanisms for energy dissipation. Increasing recognition of the positive role of wood has encouraged the reintroduction of wood to restore rivers. However, it is not clear how widely this practice is accepted, and whether traditional views of wood hazards may influence the success of such restoration projects. This paper describes a large-scale effort to increase understanding of how wood is perceived in stream channels. This project, led by H. Piegay and K.J. Gregory, involves an international group of workers from 9 countries in contrasting parts of the world. A total of 1886 surveys were given to students 20-25 years of age to test the hypothesis that the perception of wood is related to one's socio-cultural environment. Students were asked to view a set of 20 standard photographs, 10 with wood and 10 without, and to answer a set of questions related to how hazardous the scenes are perceived. Results show clear differences in perception, with students from Texas, USA, viewing streams with wood to be more dangerous, less aesthetic, and to need more improvement than those without. These perceptions contrast with those from the Pacific northwest and some areas around the world, providing clues to the potential success and acceptance of reintroducing wood in stream restoration.

  8. WOOD BIOMASS FOR ENERGY IN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Gradimir Danon

    2010-01-01

    Full Text Available Wood biomass has got its place in the energy balance of Montenegro. A little more than 6% of the total energy consumption is obtained by burning wood. Along with the appropriate state measures, it is economically and environmentally justified to expect Montenegro to more than double the utilization of the existing renewable energy sources including wood biomass, in the near future. For the purpose of achieving this goal, ‘Commercial Utilisation of the Wood Residue as a Resource for Economic Development in the North of Montenegro' project was carried out in 2007. The results of this project were included in the plan of the necessary interventions of the Government and its Agencies, associations or clusters, non-government organisations and interested enterprises. The plan was made on the basis of the wood residue at disposal and the attitude of individual subjects to produce and/or use solid bio-fuels and consists of a proposal of collection and utilisation of the wood residue for each individual district in the north of Montenegro. The basic factors of sustainability of future commercialisation of the wood residue were: availability of the wood raw material, and thereby the wood residue; the development of wood-based fuel markets, and the size of the profit.

  9. Ghost imaging with broad distance

    Science.gov (United States)

    Duan, De-Yang; Zhang, Lu; Du, Shao-Jiang; Xia, Yun-Jie

    2015-10-01

    We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is. Project supported by the National Natural Science Foundation of China (Grant Nos. 61178012, 11204156, 11304179, and 11247240), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant Nos. 20133705110001 and 20123705120002), the Scientific Research Foundation for Outstanding Young Scientists of Shandong Province, China (Grant No. BS2013DX034), and the Natural Science Foundation of Shandong Province, China (Grant No. ZR2012FQ024).

  10. Discover the benefits of residential wood heating

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This publication described how residential wood-heating systems are being used to reduce energy costs and increase home comfort. Biomass energy refers to all forms are renewable energy that is derived from plant materials. The source of fuel may include sawmills, woodworking shops, forest operations and farms. The combustion of biomass is also considered to be carbon dioxide neutral, and is not considered to be a major producer of greenhouse gases (GHG) linked to global climate change. Wood burning does, however, release air pollutants, particularly if they are incompletely burned. Incomplete combustion of wood results in dense smoke consisting of toxic gases. Natural Resources Canada helped create new safety standards and the development of the Wood Energy Technical Training Program to ensure that all types of wood-burning appliances are installed correctly and safely to reduce the risk of fire and for effective wood heating. In Canada, more than 3 million families heat with wood as a primary or secondary heating source in homes and cottages. Wood heating offers security from energy price fluctuations and electrical power failures. This paper described the benefits of fireplace inserts that can transform old fireplaces into modern heating systems. It also demonstrated how an add-on wood furnace can be installed next to oil furnaces to convert an oil-only heating system to a wood-oil combination system, thereby saving thousands of dollars in heating costs. Wood pellet stoves are another wood burning option. The fuel for the stoves is produced from dried, finely ground wood waste that is compressed into hard pellets that are loaded into a hopper. The stove can run automatically for up to 24 hours. New high-efficiency advanced fireplaces also offer an alternative heating system that can reduce heating costs while preserving Canada's limited supply of fossil fuels such as oil and gas. 13 figs.

  11. Investigation of diverse leaf-wood and coniferous wood regardin their usability for the production of wood-plastic-combinations

    International Nuclear Information System (INIS)

    By impregnation with an acrylic monomer mixture and by polymerization with gamma radiation wood-plastic combinations with high dimensional stability have been made from 34 wood species. Data for monomer uptake, density, hardness, impact bending, swelling by volume and weight, and weatherability are presented. Furthermore the attempt of an aesthetic evaluation of the wood-plastic combinations has been made. The optical impression has been compared with the technological behaviour. As a result several wood species turned out to be especially suitable for the production of wood-plastic combinations of high quality. These woods are ramin, lime, abachi, walnut, bubinga, niangon and mutenye, with some restrictions also spruce, okoume, corola pine and dibetou. (author)

  12. Migration of vascular plant species to a recent wood adjoining ancient woodland

    Directory of Open Access Journals (Sweden)

    Zbigniew Dzwonko

    2014-02-01

    Full Text Available Woodland communities can be restored by natural succession in sites adjoining ancient woodlands which can act as seed sources for trees, shrubs and woodland herbs. The influence of dominant tree species and the distance from an adjacent ancient oak-hornbeam woodland upon the floristic composition of species in a recent pine wood planted on dry rendzina soil were studied. It was found that, in spite of a 52-year long succession, the border between woods was sharp and the composition of species in the recent wood were significantly different than in the adjacent ancient woodland. Canonical correspondence analysis (CCA showed that the distance to the ancient woodland had a significant influence on species distributions in the recent wood. The numbers of species from the Querco-Fagetea class, vegetatively reproducing species and myrmecochores decreased with this distance, whereas the numbers of anemochores increased. The migration rate of many woodland species, calculated on occurrence of the farthest individuals was very slow, varying from 0.0 m year-1 to 0.38 m year-1. The restoration of the field layer vegetation in the studied pine wood was much slower than in recent deciduous woods on rich and moist soils where the migration rate of some species exceeded 1.50 m year-1. Recent woods adjacent to ancient woodlands can be more effectively colonised by woodland species only when they are dominated by broad-leaved trees with quickly decomposing litter, and the spatial continuity of these woods persists for a long period.

  13. Transcriptome analysis and RNA interference of cockroach phototransduction indicate three opsins and suggest a major role for TRPL channels

    Directory of Open Access Journals (Sweden)

    Andrew S French

    2015-07-01

    Full Text Available Our current understanding of insect phototransduction is based on a small number of species, but insects occupy many different visual environments. We created the retinal transcriptome of a nocturnal insect, the cockroach, Periplaneta americana to identify proteins involved in the earliest stages of compound eye phototransduction, and test the hypothesis that different visual environments are reflected in different molecular contributions to function. We assembled five novel mRNAs: two green opsins, one UV opsin, and one each TRP and TRPL ion channel homologs. One green opsin mRNA (pGO1 was 100-1000 times more abundant than the other opsins (pGO2 and pUVO, while pTRPL mRNA was 10 times more abundant than pTRP, estimated by transcriptome analysis or quantitative PCR (qPCR. Electroretinograms were used to record photoreceptor responses. Gene-specific in vivo RNA interference (RNAi was achieved by injecting long (596-708 bp double-stranded RNA into head hemolymph, and verified by qPCR. RNAi of the most abundant green opsin reduced both green opsins by more than 97% without affecting UV opsin, and gave a maximal reduction of 75% in ERG amplitude seven days after injection that persisted for at least 19 days. RNAi of pTRP and pTRPL genes each specifically reduced the corresponding mRNA by 90%. Electroretinogram reduction by pTRPL RNAi was slower than for opsin, reaching 75% attenuation by 21 days, without recovery at 29 days. pTRP RNAi attenuated ERG much less; only 30% after 21 days. Combined pTRP plus pTRPL RNAi gave only weak evidence of any cooperative interactions. We conclude that silencing retinal genes by in vivo RNAi using long dsRNA is effective, that visible light transduction in Periplaneta is dominated by pGO1, and that pTRPL plays a major role in cockroach phototransduction.

  14. Fine structural description of the compound eye of the Madagascar 'hissing cockroach' Gromphadorhina portentosa(Dictyoptera: Blaberidae)

    Institute of Scientific and Technical Information of China (English)

    Monalisa Mishra; Victor Benno Meyer-Rochow

    2008-01-01

    The compound eyes of the wingless adults of the Madagascar' hissing cockroach' Gromphador hina portentosa Sachum, 1853 were examined by light and electron microscopy.Each eye contains 2 400-2 500 mostly hexagonal facets. However, irregularities affecting both shape and size of the ommatidia are relatively common, especially towards the margins of the eye. An individual ommatidium of this eucone type of apposition eye contains eight retinula cells, which give rise to a centrally-fused, tiered rhabdom. The distal end of the latter is funnel-shaped and accommodates the proximal end of the cone in its midst. Further below, the rhabdom (then formed by the rhabdomeres of four retinula cells) assumes a squarish profile with microvilli aligned in two directions at right-angle to each other. Cross sections through the proximal regions of the rhabdom display triangular rhabdom outlines and microvilli (belonging to 3-4 retinula cells different from those involved in the squarish more distal rhabdom) that run in three directions inclined to one another by 120°. Overall the organization of the eye conforms to the orthopteroid pattern and particularly closely resembles that of the American cockroach Periplaneta americana. However, since G.portentosa possesses fewer ommatidia, this could be a consequence of its inability to fly. On the other hand, the large size of the facets and the voluminous rhabdoms suggest considerable absolute sensitivity and an ability to detect the plane of linearly polarized light. Based on the pattern of rnicrovillus orientations in combination with the crepuscular lifestyle G. portentosa leads and the habitat it occurs in, the prediction is made that this insect uses its green receptors for e-vector discrimination in the environment of down-welling light that reaches the forest floor.

  15. Carbon sequestration via wood burial

    Directory of Open Access Journals (Sweden)

    Zeng Ning

    2008-01-01

    Full Text Available Abstract To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1, followed by temperate (3.7 GtC y-1 and boreal forests (2.1 GtC y-1. Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC, lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.

  16. EVOLUTION OF LIGHTWEIGHT WOOD COMPOSITES

    Directory of Open Access Journals (Sweden)

    Marius C. BARBU

    2016-01-01

    Full Text Available Lightweight boards and beams in the wood-based construction and furniture industry are not a new topic. The density reduction of panels using sandwich structure with light cores was confirmed by users like doors or mobile homes more than three decades ago. Today many ways to attain a lighter wooden structure are on offer, partially in industrial application. The first one is the use of light-weight wood species like balsa, lime, pine from southern hemisphere plantations etc. limited by the availability, strength properties, gluability and so on. A second one is the sandwich structure made from hard faces like thick veneer, thin plywood, particleboard or high density thin fiberboard and cores made from honeycomb paper, very light wood species or foams like the polystyrene one. A third way to produce a light structure is to reduce the core drastically, using predesigned skeletons with special shapes and connections to the faces. The engines for these developments are on the one hand the fast growing market of knockdown furniture and on the other hand the increasing costs for energy and raw materials. Additional factors that make weight saving a primary economical objective for most producers are transportation costs, easier handling and higher acceptance among the end users. Moreover, customers demand more for ergonomical solutions regarding packaging. Many patents were generated by researchers and developers for new one-stage production processes for sandwich panels with wood- and impregnated paper-based facings made from veneers, particles or fibres and a core consisting of expandable foams, particles or embedded hard skeletons. These ideas or prototypes could be integrated in existing continuous pressing lines for wood based panels keeping some of the advantages of the continuous production technique in matters of efficiency. Some of the challenges of the light weight wooden structure are the connection in half or final parts, resistance to

  17. Tension wood and opposite wood in 21 tropical rain forest species. 1. Occurence and efficiency of G-layer

    OpenAIRE

    Clair, Bruno; Ruelle, Julien; Beauchêne, Jacques; Prévost, Marie-Françoise; Fournier, Meriem

    2006-01-01

    Wood samples were taken from the upper and lower sides of 21 naturally tilted trees from 18 families of angiosperms in the tropical rainforest in French Guyana. The measurement of growth stresses ensured that the two samples were taken from wood tissues in a different mechanical state: highly tensile stressed wood on the upper side, called tension wood and lower tensile stressed wood on the lower side, called opposite wood. Eight species had tension wood fibres with a distinct gelatinous laye...

  18. 78 FR 20119 - Broad Stakeholder Survey

    Science.gov (United States)

    2013-04-03

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 30-day... soliciting comments concerning the Broad Stakeholder Survey. DHS previously published this ICR in the Federal... responders across the Nation. The Broad Stakeholder Survey is designed to gather stakeholder feedback on...

  19. 77 FR 50144 - Broad Stakeholder Survey

    Science.gov (United States)

    2012-08-20

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 60-day... comments concerning the Broad Stakeholder Survey. DATES: Comments are encouraged and will be accepted until... across the Nation. The Broad Stakeholder Survey is designed to gather stakeholder feedback on...

  20. 76 FR 34087 - Broad Stakeholder Survey

    Science.gov (United States)

    2011-06-10

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 60-day... comments concerning the Broad Stakeholder Survey. DATES: Comments are encouraged and will be accepted until.... The Broad Stakeholder Survey is designed to gather stakeholder feedback on the effectiveness of...

  1. Violates stem wood burning sustainable development?

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    2008-01-01

    friendly effects of substituting wood burning for fossil fuels. With reference to Bent Sørensen's classical work on 'Renewable Energy' the assumption of CO2-neutrality regarding incineration is problematised when applied to plants with long rotation periods as trees. Registered CO2-emissions from wood...... burning are characterised together with particle and PAH emissions. The positive treatment of wood stove-technology in the Danish strategy for sustainable development (draft 2007) is critically evaluated and approaches to better regulation are identified....

  2. Novel perspectives in wood certification and forensics: dry wood as a source of DNA.

    OpenAIRE

    Deguilloux, Marie-France; Pemonge, Marie-Hélène; Rémy J Petit

    2002-01-01

    The importance of wood for human societies can hardly be understated. If dry wood were amenable to molecular genetic investigations, this could lead to major applications in wood forensics, certification, archaeology and palaeobotany. To evaluate the potential of wood for molecular genetic investigations, we have attempted to isolate and amplify, by PCR, DNA fragments of increasing size corresponding to all three plant genomes from different regions of 10 oak logs. Stringent procedures to avo...

  3. Reliable and non-destructive positioning of larvae of wood-destroying beetles in wood

    International Nuclear Information System (INIS)

    Living larvae of wood-destroying insects (house longhorn beetle, deathwatch) can be determined in wood by both X-ray technique and vibration measurements. For such examinations convenient commercial devices were used and tested under laboratory conditions. The methods complement each other and lead to a rationalization of the tests of wood preservatives against wood-destroying insects. It seems to be promising to apply the test methods also to timber already used for building

  4. Brazilian sawn wood price and income elasticity

    Directory of Open Access Journals (Sweden)

    Rommel Noce

    2010-09-01

    Full Text Available This study estimated the sawn wood demand price and income elasticity. Specifically it was estimated the priceelasticity of sawn wood, the cross price elasticity of wood panels and the income elasticity of Brazilian GDP. A log-log model withcorrection through outline of the mobile average (MA(1 was used, adjusted for the period of 1971 to 2006, which showed to bestable, with satisfactory significance levels. It was observed that sawn wood demand is inelastic in relation to price and elastic inrelation to income.

  5. European wood-pastures in transition

    DEFF Research Database (Denmark)

    Wood-pastures are important elements of European cultural identity and have an exceptional ecological value, yet they are in decline all over Europe. The structure of wood-pastures is strongly influenced by grazing and multiple other land uses and by local and regional environmental conditions....... European Wood-Pastures in Transition examines the diverse expressions of wood-pastures across Europe. It provides a new perspective, using a social-ecological framework to explore social and ecological values, governing institutions, threats and conservation approaches. It explores the major drivers...

  6. George Woods and the World Bank

    OpenAIRE

    Oliver, Robert W.

    1989-01-01

    PREFACE. George David Woods became the fourth president of the World Bank on January 1, 1963. John F. Kennedy, personally, urged Woods to accept. In August, 1962, Eugene Black invited Woods to the White House where Kennedy told Woods, in effect: Everything we in the United States have done since the end of the war, including the Marshall Plan, to try to build a peaceful and stable world is threatened by the growing gap between the poor and the rich countries. If that is not sol...

  7. Characteristics of Wood ASH/OPC Concrete

    OpenAIRE

    Abdullahi, M

    2006-01-01

    The study presents the behaviour of wood ash / OPC concrete. Chemical analysis of wood ash, bulk density, sieve analysis and specific gravity of wood ash and aggregates, consistency, setting time and slump test of the fresh paste were conducted to determine the suitability of the materials for concrete making. Mix ratio of 1:2:4 and percentage replacement level of 0, 10, 20, 30 and 40 percents of cement by wood ash were used. 150mm´150mm cubes were cast, cured and crushed at 28 and 60 days to...

  8. Wood energy 2000; Bois energie 2000

    Energy Technology Data Exchange (ETDEWEB)

    Druette, L. [Centre Scientifique et Technique du Batiment, (CSTB), 44 - Nantes (France); Lacome, T. [AFNOR, 75 - Paris (France); Roy, C. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France)] [and others

    2000-07-01

    The deregulation of the Electric Market and the opening of the Green Certificate exchange market force the set up of renewable energies. The wood, which is for most of european countries an important part of renewable fuel, should see the increase of its utilization. This conference on the wood energy deals the main aspects of this energy development. The papers present the wood burning furnaces technology assessment, the wood fuel market and the standardization of the appliances in this domain. Some papers also include the consequences of the big storms of december 1999. (A.L.B.)

  9. Study on Organic Wood-flour Putty

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This work was undertaken to research organic wood-flour putty as wooden surface undercoat. Four types of wood-flour (300, 500, 800 and 1 000 mesh) were prepared through the technological processes of shattering, coarse grinding and fine grinding. And latex (16% of solid content) and two kinds of agents (A and B) were added into the putty. In this experiment, effects of agent and particle size of wood-flour on properties of organic wood-flour putty, such as painting properties, water resistance, and abrasive...

  10. Adenovirus-mediated Foxp3 expression in lung epithelial cells reduces airway inflammation in ovalbumin and cockroach-induced asthma model.

    Science.gov (United States)

    Park, Soojin; Chung, Hwan-Suck; Shin, Dasom; Jung, Kyung-Hwa; Lee, Hyunil; Moon, Junghee; Bae, Hyunsu

    2016-01-01

    Foxp3 is a master regulator of CD4(+)CD25(+) regulatory T-cell (Treg) function and is also a suppressor of SKP2 and HER2/ErbB2. There are an increasing number of reports describing the functions of Foxp3 in cell types other than Tregs. In this context, we evaluated the functions of Foxp3 in ovalbumin- and cockroach-induced asthma models. Foxp3-EGFP-expressing adenovirus or EGFP control adenovirus was administered intratracheally (i.t.), followed by challenge with ovalbumin (OVA) or cockroach extract to induce asthma. Th2 cytokine and immune cell profiles of bronchoalveolar lavage fluid (BALF), as well as serum IgE levels, were analyzed. Histological analyses were also conducted to demonstrate the effects of Foxp3 expression on airway remodeling, goblet cell hyperplasia and inflammatory responses in the lung. Adenoviral Foxp3 was expressed only in lung epithelial cells, and not in CD4(+) or CD8(+) cells. BALF from Foxp3 gene-delivered mice showed significantly reduced numbers of total immune cells, eosinophils, neutrophils, macrophages and lymphocytes in response to cockroach allergen or OVA. In addition, Foxp3 expression in the lung reduced the levels of Th2 cytokines and IgE in BALF and serum, respectively. Moreover, histopathological analysis also showed that Foxp3 expression substantially inhibited eosinophil infiltration into the airways, goblet cell hyperplasia and smooth muscle cell hypertrophy. Furthermore, when Tregs were depleted by diphtheria toxin in Foxp3(DTR) mice, the anti-asthmatic functions of Foxp3 were not altered in OVA-challenged asthma models. In this study, our results suggest that Foxp3 expression in lung epithelial cells, and not in Tregs, inhibited OVA- and cockroach extract-induced asthma. PMID:27633092

  11. Effects of Two Temperature Storage Regimes on the Efficacy of 3 Commercial Gel Baits against the German Cockroach, Blattella germanica L. (Dictyoptera: Blattellidae

    Directory of Open Access Journals (Sweden)

    E Oz

    2010-09-01

    Full Text Available "nBackground: To compare the effectiveness of 3 commercial gel bait formulations containing fipronil (Goliathã Cockroach Gel 0.05% AI, chlorpyrifos-A (Clean Baitã Gel, 2% AI, and chloropyrifos-B (Serpaã Gel 2% AI against German cock­roaches (Blattella germanica when stored at 23°C and 30° C after treatment."nMethods: Laboratory bioassays consisted of placing groups of fifteen cockroaches (a random combination of adult, mixed sex and large nymphs-stage 6 into a 5 L cylindrical plastic container with one drop of product (avg 0.10 g ± 0.01 g applied to a 76 mm x 26 mm glass microscope slide affixed to the bottom of each container (one product tested per container. Cumula­tive mortality was assessed at 6 h, 1, 2, 3, 4, and 5 d after application. To determine the further effects of storage tempera­ture after treatment on residual activity of the gels, a drop of each product was applied to separate glass microscope slides and stored at either 23º C (warm or 30º C (hot under dark conditions for 0, 1, 7, 14, 30, 45, 60 and 90 d after applica­tion."nResults: Freshly applied baits (day 0 containing fipronil provided complete cockroach mortality (100% within 5 d whereas chloryrifos-A and chlorpyrifos-B provided »72% and 88% mortality, respectively. Generally, cockroach mortality was greater when gels were stored at 30°C compared with 23º C."nConclusion: The fipronil gel formulation proved to be as efficacious as the chlorpyrifos gels and in some instances sur­pased the latter formulations depending on storage time and temperature by providing »90% mortality at 90 d post treat­ment.

  12. Social Housing: wood prefabrication techniques

    Directory of Open Access Journals (Sweden)

    Tiziana Ferrante

    2012-10-01

    Full Text Available Student housing, a particular and quite significant part of social housing, and innovation in processing and production of industrial building components made of a material (wood not adequately inquired: two fields of research that have been explored for a long time allowing here to share and compare experiences gained thus far. By a selection of samples of wooden student housing in Europe we have documented the performances of this material and we have underlined, at the same time, through what happens abroad, the need of an organic national social housing plan that can meet an unsatisfied demand and boost the construction industry during this particular stage of economic crisis.

  13. Energy Efficient Wood Fuel Drying

    Energy Technology Data Exchange (ETDEWEB)

    Renstroem, Roger

    2004-04-01

    With reference to the reduction of carbon dioxide emissions, biofuel is pointed out as an important substitute for fossil fuels. The Swedish Government favours the use of biofuel by imposing taxes on fossil fuels. However, biofuel is a limited resource and it is therefore important that we develop efficient systems for the production and utilization of this limited resource. This thesis is based on six papers out of which five are experimental and treats the drying of wood in spouted bed co-generation dryers. The sixth paper deals with the integration of a co-generation dryer into the energy system of a sawmill.

  14. Variation in wood nutrients along a tropical soil fertility gradient.

    Science.gov (United States)

    Heineman, Katherine D; Turner, Benjamin L; Dalling, James W

    2016-07-01

    Wood contains the majority of the nutrients in tropical trees, yet controls over wood nutrient concentrations and their function are poorly understood. We measured wood nutrient concentrations in 106 tree species in 10 forest plots spanning a regional fertility gradient in Panama. For a subset of species, we quantified foliar nutrients and wood density to test whether wood nutrients scale with foliar nutrients at the species level, or wood nutrient storage increases with wood density as predicted by the wood economics spectrum. Wood nutrient concentrations varied enormously among species from fourfold in nitrogen (N) to > 30-fold in calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P). Community-weighted mean wood nutrient concentrations correlated positively with soil Ca, K, Mg and P concentrations. Wood nutrients scaled positively with leaf nutrients, supporting the hypothesis that nutrient allocation is conserved across plant organs. Wood P was most sensitive to variation in soil nutrient availability, and significant radial declines in wood P indicated that tropical trees retranslocate P as sapwood transitions to heartwood. Wood P decreased with increasing wood density, suggesting that low wood P and dense wood are traits associated with tree species persistence on low fertility soils. Substantial variation among species and communities in wood nutrient concentrations suggests that allocation of nutrients to wood, especially P, influences species distributions and nutrient dynamics in tropical forests. PMID:26922861

  15. High load of multi-drug resistant nosocomial neonatal pathogens carried by cockroaches in a neonatal intensive care unit at Tikur Anbessa specialized hospital, Addis Ababa, Ethiopia

    Directory of Open Access Journals (Sweden)

    Tilahun Birkneh

    2012-03-01

    Full Text Available Abstract Background Cockroaches have been described as potential vectors for various pathogens for decades; although studies from neonatal intensive care units are scarce. This study assessed the vector potential of cockroaches (identified as Blatella germanica in a neonatal intensive care unit setup in Tikur Anbessa Hospital, Addis Ababa, Ethiopia. Methods A total of 400 Blatella germanica roaches were aseptically collected for five consecutive months. Standard laboratory procedures were used to process the samples. Results From the external and gut homogenates, Klebsiella oxytoca, Klebsiella pneumoniae, Citrobacter spp. Enterobacter cloacae, Citrobacter diversus, Pseudomonas aeruginosa, Providencia rettgeri, Klebsiella ozaenae, Enterobacter aeruginosa, Salmonella C1, Non Group A streptococcus, Staphylococcus aureus, Escherichia coli, Acinetobacter spp. and Shigella flexneri were isolated. Multi-drug resistance was seen in all organisms. Resistance to up to all the 12 antimicrobials tested was observed in different pathogens. Conclusion Cockroaches could play a vector role for nosocomial infections in a neonatal intensive care unit and environmental control measures of these vectors is required to reduce the risk of infection. A high level of drug resistance pattern of the isolated pathogens was demonstrated.

  16. The Wood Anatomy of Rubiaceae tribes Anthospermeae and Paederieae

    NARCIS (Netherlands)

    Koek-Noorman, J.; Puff, Ch.

    1983-01-01

    Detailed wood anatomical descriptions are given for the genera Anthospermum, Nenax, Phyllis, Carpacoce, Coprosma, Neogaillonia, Crocyllis, Plocama and Spermadictyon, and miscellaneous wood anatomical data on the genera Normandia, Pomax, Opercularia, Leptodermis and Aitchisonia. The wood anatomical v

  17. Microwave Irradiation Treatment of Wood Flour and Its Application in PVC-Wood Flour Composites

    Institute of Scientific and Technical Information of China (English)

    HU Shengfei; CHEN Wen; LIU Weihua; LI Huaxing

    2007-01-01

    The technique of microwave irradiation induced free radical bulk- polyaddition reactions in porous wood flour was used to modify wood flour. The behaviors of the modified wood flour under microwave irradiation, such as thermal stability and moisture sorption properties, were studied. A kind of semiinterpenetrating polymer network wood four (Semi-IPN-WF) can be formed through polymerization of MMA in the porous wood flour by microwave irradiation, and the thermal decomposition temperature of the semi-IPN-WF is considerably increased. PVC/Semi-IPN-WF composites were prepared by melt mixing in double rolls,which exhibit improved rheological properties, lower water sorption properties and outstanding mechanical performances.

  18. Effect of Wood Fillers on the Viscoelastic and Thermophysical Properties of HDPE-Wood Composite

    Directory of Open Access Journals (Sweden)

    M. Tazi

    2016-01-01

    Full Text Available Wood polymer composites (WPC have well proven their applicability in several fields of the plasturgy sector, due to their aesthetics and low maintenance costs. However, for plasturgy applications, the characterization of viscoelastic behavior and thermomechanical and thermophysical properties of WPC with the temperature and wood filler contents is essential. Therefore, the processability of polymer composites made up with different percentage of wood particles needs a better understanding of materials behaviors in accordance with temperature and wood particles contents. To this end, a numerical analysis of the viscoelastic, mechanical, and thermophysical properties of composite composed of high density polyethylene (HDPE reinforced with soft wood particles is evaluated.

  19. COMPOSITES FROM RECYCLED WOOD AND PLASTICS

    Science.gov (United States)

    The ultimate goal of this research was to develop technology to convert recycled wood fiber and plastics into durable products that are recyclable and otherwise environmentally friendly. Two processing technologies were used to prepare wood-plastic composites: air-laying and melt...

  20. Wood and leaf anatomy of Opiliaceae

    NARCIS (Netherlands)

    Koek-Noorman, J.; Rijckevorsel, v. P.

    1983-01-01

    The wood and leaf anatomy of representatives of the 9 genera of the Opiliaceae are described in detail. It is possible to separate the genera on the base of both wood- and leaf anatomical characters. Herein the presence of cystoliths of varying shape and size is important. Some comments on the taxon

  1. Reactivity and burnout of wood fuels

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo

    This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile...

  2. Turbulence and Araki-Woods factors

    DEFF Research Database (Denmark)

    Sasyk, R.; Törnquist, A.; Törnquist, Asger Dag

    2010-01-01

    Using Baire category techniques we prove that Araki-Woods factors are not classifiable by countable structures. As a result, we obtain a far reaching strengthening as well as a new proof of the well-known theorem of Woods that the isomorphism problem for ITPFI factors is not smooth. We derive...

  3. Least cost supply strategies for wood chips

    DEFF Research Database (Denmark)

    Möller, Bernd

    The abstract presents a study based on a geographical information system, which produce  cost-supply curves by location for forest woods chips in Denmark.......The abstract presents a study based on a geographical information system, which produce  cost-supply curves by location for forest woods chips in Denmark....

  4. Evaluation of Paulownia elongata wood polyethylene composites

    Science.gov (United States)

    Paulownia wood flour (PWF), a byproduct of milling lumber, was employed as a bio-filler and blended with high density polyethylene (HDPE) via extrusion. Paulownia wood (PW) shavings were milled through a 1-mm screen then separated via shaking into various particle fractions using sieves (#30 - < #2...

  5. Bioenergy research programme. Yearbook 1996. Production of wood fuels; Bioenergian tutkimusohjelma. Vuosikirja 1996. Puupolttoaineiden tuotantotekniikka

    Energy Technology Data Exchange (ETDEWEB)

    Nikku, P. [ed.

    1997-12-01

    The aim of the programme is to increase the use of economically profitable and environmentally sound bioenergy by improving the competitiveness of present peat and wood fuels. Research and development projects will also develop new economically competitive biofuels, new equipment and methods for production, handling and utilisation of biofuels. The total funding for 1996 was 27.3 million FIM and the number of projects 63. The number of projects concerning wood fuels production was 36. The main goals of the research are to develop new production methods for wood fuels in order to decrease the production costs to the level of imported fuels (100 km distance). The second goal is to decrease the small scale production costs by 20 % as compared with the 1992 technology level. Also, new harvesting technology and new work methods will be developed for forest owners and small-entrepreneurs in the course of the programme. Results of the projects carried out in 1996 in this programme are presented in this publication. The integrated harvesting methods, which supply both raw material to wood products industry and wood fuel for energy production, have been chosen the main research areas because they seem to be most promising. Most of the projects are focused in the wood fuel production from first thinnings and from final fellings. The projects broadly covered the research area focusing from material flows, productivity studies, basic wood properties to several case studies. The follow up project of Evaluation-drum chipper was completed with good fuel quality and productivity results. Also the large Forest Energy Project of Central Finland was completed. The project was a significant technology transfer and information dissemination project. (orig.)

  6. Tissue damage after acute intoxication by polychlorinated biphenyls (PCBs) in cockroaches Blattella germanica

    OpenAIRE

    Lambiase, S; Zhang, Y.; P. Morbini; M. Fasola

    2009-01-01

    It is common knowledge that polychlorinated biphenyls (PCBs) represent a serious threat to the health of both vertebrates and invertebrates. As far as the former are concerned, especially as regards human beings, a broad literature describes the direct and indirect effects induced by the PCBs on their systems and organs. Among invertebrates, the information available is mostly related to arthropods and is, however, very scarce. The aim of this work was to evaluate the effects of polychlorinat...

  7. STUDY OF MECHANICAL PROPERTIES OF WOOD POLYACRYLONITRILE COMPOSITES

    Directory of Open Access Journals (Sweden)

    Mohammed Abid Ali

    2011-10-01

    Full Text Available Wood polyacrolonitrile composite (WPC from neem ,mango andcork wood was synthesized. The process was carried out through benzoyl peroxide(0.05mol/lcatalyzed impregnation polymerization of acrylonitrile,4mol/l,6mol/l into cork woodand mango wood in benzene medium at 75+-10c.The properties of WPCs over untreated woods were evaluated in terms of compressive test ,hardness of wood were improvedwith impregnation of polyacrylonitrile .Impregnation of polyacyrlonitrile (PAN into neem wood,mango wood and cork woods were was confirmed through scanning electron microscope.

  8. Wood for energy production. Technology - environment - economy

    Energy Technology Data Exchange (ETDEWEB)

    Serup, H.; Falster, H.; Gamborg, C. [and others

    1999-10-01

    `Wood for Energy Production`, 2nd edition, is a readily understood guide to the application of wood in the Danish energy supply. The first edition was named `Wood Chips for Energy Production`. It describes the wood fuel from forest to consumer and provides a concise introduction to technological, environmental, and financial matters concerning heating systems for farms, institutions, district heating plants, and CHP plants. The individual sections deal with both conventional, well known technology, as well as the most recent technological advances in the field of CHP production. The purpose of this publication is to reach the largest possible audiance, and it is designed so that the layman may find its background information of special relevance. `Wood for Energy Production` is also available in German and Danish. (au)

  9. Particulate emissions from residential wood combustion

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo; Jensen, Ole Michael; Tarelho, Luis A. C.;

    Residential wood combustion (RWC) in fireplaces and conventional appliances is the main contributor to fine particulate matter (PM2.5) emissions in Denmark and Portugal representing more than 30% of the total emissions [1;2]. Such estimations are uncertain concerning the wood consumption.......5 emissions within a specific “wood burning living area”, but one Danish study exists [4]. In previous inventories distinct combustion air operation modes and the growing penetration of automate wood-burning stoves have not been considered. The present work aims to discuss opportunities for improving...... Portuguese combustion practices in laboratory tests. This study highlights that the previous PM2.5 emission inventories in Denmark and Portugal did not consider the possible variations on fuel moisture, dimensions of wood-logs and air-inlet operation patterns, although they are very important, especially...

  10. Dimensional stability of heat treated wood floorings

    Directory of Open Access Journals (Sweden)

    Vjekoslav Živković

    2008-07-01

    Full Text Available Heat treated wood (HTW is successfully applied for floorings due to its better moisture resistance, increased dimensional stability, and uniform colour change to darker, brownish colours. The aim of this work was to define the hygroscopic range and equilibrium moisture content at ambient conditions of heat treated wood of two wood species – ash and beech. Material was treated at two temperature levels, 190 and 210 °C, and the properties were compared with native wood. The reduction in dimensional changes is expressed by volumetric shrinking and Anti Shrink Efficiency (ASE. Additionally, parquet elements were made out of such HTW, oil-impregnated and waxed, and subsequently tested for water vapour and liquid water permeability. Shrinking gradients of HTW were not reduced in comparison with native beech wood, but the absolute reduction in water uptake resulted in cca 50 % lower EMC values and up to cca 60 % improved ASE values. Surface treatment further improved the hygroscopic properties of HTW.

  11. Wood for energy production. Technology - environment - economy

    International Nuclear Information System (INIS)

    'Wood for Energy Production', 2nd edition, is a readily understood guide to the application of wood in the Danish energy supply. The first edition was named 'Wood Chips for Energy Production'. It describes the wood fuel from forest to consumer and provides a concise introduction to technological, environmental, and financial matters concerning heating systems for farms, institutions, district heating plants, and CHP plants. The individual sections deal with both conventional, well known technology, as well as the most recent technological advances in the field of CHP production. The purpose of this publication is to reach the largest possible audiance, and it is designed so that the layman may find its background information of special relevance. 'Wood for Energy Production' is also available in German and Danish. (au)

  12. Cockroaches Allergens Trigger Asthma Prevention Study%蟑螂过敏原引发哮喘的防治研究

    Institute of Scientific and Technical Information of China (English)

    孙金; 张锡平; 赵庆武

    2011-01-01

    目的:了解蟑螂过敏原引发哮喘的作用机制,探寻蟑螂引发哮喘的防治方法.方法:对全市8家医院的呼吸科,儿科的哮喘病例80例进行问卷调奁和蟑螂抗原皮肤点刺试验.结果:哮喘患者对蟑螂抗原的反应性的相关性是显著的,其与阳性也是显著相关的(P<0.001),其阳性比率为40.0%,成人阳性比率为45.0%,儿童阳性比率为35.0%.男性阳性比率为56.25%,女性阳性比率为47.5%.结论:蟑螂是哮喘患者主要变应原之一,一般成人的阳性比率比儿童高,男性比女性高.免疫治疗和灭蟑是蟑螂过敏原引发哮喘主要有效的防治方法.%Objective:Understand cockroach allergens trigger asthma mechanism of action,and explore cockeroach trigger astma and the control.Metheods:the 83 armour hospital,pediatrics and an allergy clinic asthma cases 80 cases of questionnaire and cockroach antigen skin prick test.Results:Asthma patients to cockroach antigen reactive correlation is remarkable, its and positive is also significant(P<0.001),its positive 40.0%,adult positive ratio fot ratio for accounting for 36.0%,children positive 35.0%,male ratio fot positive ratio for 56.25%,women postive ratio for 47.5%.Concusion:Cockroaches are asthma patients main allergens,one of the positive ratio than the average adult children high,high males than females.Immune therapy and destroy Zhang is a cockroach allergens trigger asthma main effective prevention methods.

  13. Wood Identification of 18th Century Furniture. Interpreting Wood Naming Inventoires

    Directory of Open Access Journals (Sweden)

    Rocio Astrid BERNAL

    2011-09-01

    Full Text Available The 18th century Portuguese church furniture represents an extraordinary richness recognised worldwide, which demands safeguarding and valorisation. The identification of the wood of furniture artworks is the most important component for its comprehension and preservation. In this work wood anatomical characters of an 18th century Portuguese decorative furniture set from the Colegiada de São Martinho de Cedofeita, in Porto, were analysed to identify the woods used for manufacturing and to clarify their common names. Furthermore, the objectives were to recognise some of the criteria for choice of wood as well as the source of each wood. The woods identified from 16 fragments belong to Apuleia sp., Acacia sp., Neolamarckia sp. and Castanea sativa. Apuleia sp. and Acacia sp. woods most likely arrived from Brazil, while the Neolamarckia sp. woods likely arrived from India and the C. sativa woods from Portugal. The results are in accordance with the known Portuguese colonial sea routes of the 15th -18th centuries. Interestingly the terms found in the inventories can refer to finishing methods instead to the name of the woods, as for instance “oil wood” can refer to “oiled wood” or “linseed oiled wood”. The species choice may be related to the mechanical properties of the wood as well as the original tree size. Two large planks of Acacia sp. were used for the top of the “Portuguese arcaz”, and Apuleia sp. was found on main structural elements of this set of furniture, suggesting that wood colour was also important. Woods from Neolamarckia sp. and C. sativa, were also identified, being Castanea wood present only in the most recent pieces of the furniture set.

  14. METAL CORROSION IN WATERBORNE PRESERVATIVE- TREATED WOOD

    Directory of Open Access Journals (Sweden)

    Krisdianto Sugiyanto

    2010-12-01

    Full Text Available The rigidity and firmness of wooden construction and furniture those are joined by metal screws depend on corrosion rate of these metals. This paper examines the weight-loss percentage of metal screws used in wood samples that have been treated with water-borne preser vative (i.e.3% borax boric acid and 3% diffusol CB and concurrently investigates the effect of brake fluid on preventing metal corrosion. Wood samples tested included three acacia and one eucalypts wood species which were grouped into sapwood and heartwood containing samples. Wood samples fastened with metal screws were freely suspended in glass jars that contained 25 ml of sulphuric acid (H2SO4 to keep the humidity rate above 90%. After 12 months, the metal screws lost their weight due to the corrosion brought about by the related factors either in separate individual or in combination, which comprised brake and fluid-dipping , wood species, wood portion (sapwood and heartwood, kinds of preser vatives used. Corrosion rates of metal screws fastened in eucalypts wood sample as indicated by the screw-weight loss (i.e. 5.8% was more severe than that fastened in acacia wood. Furthermore, corrosion rate of metal screws as fixed firmly in sapwood sample proceeded faster than that in heartwood. This might be caused by the higher moisture content in sapwood. On the other hand, corrosion rate of the screws as fastened in waterborne-preser vative-treated wood samples was greater than that in non-preser ved wood due to electrokinetic characteristics and ionic potential exhibited by the preser vative thereby intensif ying the screw-corrosion process. Meanwhile, less severe corrosion was obser ved and recorded on the screws pre-dipped in brake fluid compared to those on the non-dipped screws

  15. Quantitative wood anatomy - practical guidelines

    Directory of Open Access Journals (Sweden)

    Georg evon Arx

    2016-06-01

    Full Text Available Quantitative wood anatomy analyzes the variability of xylem anatomical features in trees, shrubs and herbaceous species to address research questions related to plant functioning, growth and environment. Among the more frequently considered anatomical features are lumen dimensions and wall thickness of conducting cells, fibers and several ray properties. The structural properties of each xylem anatomical feature are mostly fixed once they are formed, and define to a large extent its functionality, including transport and storage of water, nutrients, sugars and hormones, and providing mechanical support. The anatomical features can often be localized within an annual growth ring, which allows to establish intra-annual past and present structure-function relationships and its sensitivity to environmental variability. However, there are many methodological obstacles to overcome when aiming at producing (large data sets of xylem anatomical data.Here we describe the different steps from wood sample collection to xylem anatomical data, provide guidance and identify pitfalls, and present different image-analysis tools for the quantification of anatomical features, in particular conducting cells. We show that each data production step from sample collection in the field, microslide preparation in the lab, image capturing through an optical microscope and image analysis with specific tools can readily introduce measurement errors between 5 to 30% and more, whereby the magnitude usually increases the smaller the anatomical features. Such measurement errors – if not avoided or corrected – may make it impossible to extract meaningful xylem anatomical data in light of the rather small range of variability in many anatomical features as observed, for example, within time series of individual plants. Following a rigid protocol and quality control as proposed in this paper is thus mandatory to use quantitative data of xylem anatomical features as a powerful

  16. Broad Prize: Do the Successes Spread?

    Science.gov (United States)

    Samuels, Christina A.

    2011-01-01

    When the Broad Prize for Urban Education was created in 2002, billionaire philanthropist Eli Broad said he hoped the awards, in addition to rewarding high-performing school districts, would foster healthy competition; boost the prestige of urban education, long viewed as dysfunctional; and showcase best practices. Over the 10 years the prize has…

  17. Implementation of new technologies in wood industry and their effect in wood products quality

    Directory of Open Access Journals (Sweden)

    ELVA ÇAUSHI

    2014-06-01

    Full Text Available There are about 300 companies producing furniture and about 250 small and medium enterprises (SME producing sawn timber, which operate in the field of wood industry in Albania. This wood industry production is being challenged by the increasing demand in the domestic market, ranging from kitchen furniture to office and schools furniture, bedroom furniture, doors, windows, and saw timber in different dimensions. The production from the wood industry can fulfill about 80% of the domestic market demand. The remaining 20% of domestic market needs in wood furniture are afforded by import. Small entities do not make serious investment in technology. Big enterprises such as Ardeno in Tirana, Biçaku in Durres, Shaga in Tirana, Ital-wood in Elbasan, Dafinori in Shkoder, etc., have made remarkable investments in their technology. They have installed several mechanized lines of production. So, Ital-wood has invested in a mechanized saw timber production line; Bicaku in wood panels coated with PVC lines; Dafinori in a wood handrail production technologic line; Ardeno in wooden chairs production technologic lines, and Shaga in the production of furniture with particle panels. These enterprises are using modern numerical command machines, vacuum presses for gluing PVC, cutting equipment for panels with laser ray, finishing lines with electrostatic field, modern lines of pneumatic transport for wood dust etc. These investments in new technologies have increased the quantity and quality of native wood products.

  18. Propagation behavior of acoustic wave in wood

    Institute of Scientific and Technical Information of China (English)

    Huadong Xu; Guoqi Xu; Lihai Wang; Lei Yu

    2014-01-01

    We used acoustic tests on a quarter-sawn poplar timbers to study the effects of wood anisotropy and cavity defects on acoustic wave velocity and travel path, and we investigated acoustic wave propagation behavior in wood. The timber specimens were first tested in unmodified condition and then tested after introduction of cavity defects of varying sizes to quantify the transmitting time of acoustic waves in laboratory conditions. Two-dimensional acoustic wave contour maps on the radial section of specimens were then simulated and analyzed based on the experimental data. We tested the relationship between wood grain and acoustic wave velocity as waves passed in various directions through wood. Wood anisotropy has significant effects on both velocity and travel path of acoustic waves, and the velocity of waves passing longitudinally through timbers exceeded the radial velocity. Moreover, cavity defects altered acoustic wave time contours on radial sections of timbers. Acous-tic wave transits from an excitation point to the region behind a cavity in defective wood more slowly than in intact wood.

  19. Utilisation of Estonian energy wood resources

    International Nuclear Information System (INIS)

    In the end of the Soviet period in the 1980s, a long-term energy programme for Estonia was worked out. The energy system was planned to be based on nuclear power and the share of domestic alternative sources of energy was low. The situation has greatly changed after the re-establishment of the Estonian independence, and now wood and peat fuels play an important role in the energy system. Energy consumption in Estonia decreased during the period 1970-1993, but this process has less influenced the consumption of domestic renewable fuels - peat and wood. It means that the share of these fuels has grown. The investment on substitution of imported fossil fuels and on conversion of boiler plants from fossil fuels to domestic fuels has reached the level of USD 100 million. The perspectives of the wood energy depend mainly on two factors; the resources and the price of wood energy compared with other fuels. The situation in wood market influences both the possible quantities and the price. It is typical that the quickly growing cost of labour power in Estonia is greatly affecting the price of energy wood. Though the price level of fuel peat and wood chips is lower than the world market price today, the conditions for using biofuels could be more favourable, if higher environmental fees were introduced. In conjunction with increasing utilisation of biofuels it is important to evaluate possible emissions or removal of greenhouse gases from Estonian forests 3 refs

  20. Wood quality changes caused by mineral fertilization

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Sette Jr

    2014-06-01

    Full Text Available The diverse and important use of wood from fast growth eucalyptus plantations requires the analysis of the effect of mineral fertilizers on wood quality. The objective of this study was to evaluate the anatomical characteristics and wood density from Eucalyptus grandis trees (3 m x 2 m spacing fertilized with potassium and sodium (at planting, 6 th and 12th month. Fifteen (15 6 years old eucalyptus trees were selected (5 trees/treatment, cut and wood samples at DBH (1,3 m were taken for anatomical characteristics (fiber and vessels and wood density analysis. Results showed that eucalyptus trees treated with mineral fertilizers did not show significant alteration in average wood density, with radial profile model common to all three treatments, characterized by a values increase in the region next to the pith, toward to bark. Mineral fertilization influenced wood anatomical characteristics: treatment with sodium was characterized by thinner walls and lumen larger diameter; in treatment with potassium, larger vessels were detected.

  1. Utilisation of Estonian energy wood resources

    Energy Technology Data Exchange (ETDEWEB)

    Muiste, P.; Tullus, H.; Uri, V. [Estonian Agricultural University, Tartu (Estonia)

    1996-12-31

    In the end of the Soviet period in the 1980s, a long-term energy programme for Estonia was worked out. The energy system was planned to be based on nuclear power and the share of domestic alternative sources of energy was low. The situation has greatly changed after the re-establishment of the Estonian independence, and now wood and peat fuels play an important role in the energy system. Energy consumption in Estonia decreased during the period 1970-1993, but this process has less influenced the consumption of domestic renewable fuels - peat and wood. It means that the share of these fuels has grown. The investment on substitution of imported fossil fuels and on conversion of boiler plants from fossil fuels to domestic fuels has reached the level of USD 100 million. The perspectives of the wood energy depend mainly on two factors; the resources and the price of wood energy compared with other fuels. The situation in wood market influences both the possible quantities and the price. It is typical that the quickly growing cost of labour power in Estonia is greatly affecting the price of energy wood. Though the price level of fuel peat and wood chips is lower than the world market price today, the conditions for using biofuels could be more favourable, if higher environmental fees were introduced. In conjunction with increasing utilisation of biofuels it is important to evaluate possible emissions or removal of greenhouse gases from Estonian forests 3 refs.

  2. Solvolytic liquefaction of wood under mild conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.M.

    1982-04-01

    Conversion of wood to liquid products requires cleavage of bonds which crosslink the wood structure. This study examines a low-severity wood solubilization process utilizing a solvent medium consisting of a small amount of sulfuric acid and a potentially wood-derivable alcohol. In one half hour of reaction time at 250/sup 0/C under 15 psia starting nitrogen pressure, over 95% of the wood (maf) was rendered acetone-soluble. The product is a soft, black, bitumen-like solid at room temperature but readily softens at 140/sup 0/C. Between 25 and 50% of the original wood oxygen, depending on alcohol used, was removed as water. Approximately 2 to 17% of the alcohols were retained in the product. Gel permeation chromatography showed that the product's median molecular weight is around 300. Based on experimental and literature results, a mechanism for wood solubilization is proposed. This involves protonation of the etheric oxygen atoms, leading to subsequent bond scission to form carbonium ions which are stabilized by solvent alkoxylation. At severe conditions, polymerization and condensation reactions result in acetone-insoluble materials.

  3. Towards a worldwide wood economics spectrum.

    Science.gov (United States)

    Chave, Jerome; Coomes, David; Jansen, Steven; Lewis, Simon L; Swenson, Nathan G; Zanne, Amy E

    2009-04-01

    Wood performs several essential functions in plants, including mechanically supporting aboveground tissue, storing water and other resources, and transporting sap. Woody tissues are likely to face physiological, structural and defensive trade-offs. How a plant optimizes among these competing functions can have major ecological implications, which have been under-appreciated by ecologists compared to the focus they have given to leaf function. To draw together our current understanding of wood function, we identify and collate data on the major wood functional traits, including the largest wood density database to date (8412 taxa), mechanical strength measures and anatomical features, as well as clade-specific features such as secondary chemistry. We then show how wood traits are related to one another, highlighting functional trade-offs, and to ecological and demographic plant features (growth form, growth rate, latitude, ecological setting). We suggest that, similar to the manifold that tree species leaf traits cluster around the 'leaf economics spectrum', a similar 'wood economics spectrum' may be defined. We then discuss the biogeography, evolution and biogeochemistry of the spectrum, and conclude by pointing out the major gaps in our current knowledge of wood functional traits. PMID:19243406

  4. Differences in susceptibility to German cockroach frass and its associated proteases in induced allergic inflammation in mice

    Directory of Open Access Journals (Sweden)

    Herman Nancy

    2007-12-01

    Full Text Available Abstract Background Cockroach exposure is a major risk factor for the development of asthma. Inhalation of fecal remnants (frass is the likely sensitizing agent; however isolated frass has not been tested for its ability to induce experimental asthma in mice. Methods Mice (Balb/c or C57Bl/6 were sensitized and challenged with GC frass or GC frass devoid of proteases and measurements of airway inflammation and hyperresponsiveness were performed (interleukin (IL-5, -13, and interferon gamma (IFNγ levels in bronchoalveolar lavage fluid, serum IgE levels, airway hyperresponsiveness, cellular infiltration, and mucin production. Results Sensitization and challenge of Balb/c mice with GC frass resulted in increased airway inflammation and hyperresponsiveness. C57Bl/6 mice were not susceptible to this model of sensitization; however they were sensitized to GC frass using a more aggressive sensitization and challenge protocol. In mice that were sensitized by inhalation, the active serine proteases in GC frass played a role in airway hyperresponsiveness as these mice had less airway hyperresponsiveness to acetylcholine and less mucin production. Proteases did not play a role in mediating the allergic inflammation in mice sensitized via intraperitoneal injection. Conclusion While both strains of mice were able to induce experimental asthma following GC frass sensitization and challenge, the active serine proteases in GC frass only play a role in airway hyperresponsiveness in Balb/c mice that were susceptible to sensitization via inhalation. The differences in the method of sensitization suggest genetic differences between strains of mice.

  5. The complete mitochondrial genome of the cockroach Eupolyphaga sinensis (Blattaria: Polyphagidae) and the phylogenetic relationships within the Dictyoptera.

    Science.gov (United States)

    Zhang, Yan-yan; Xuan, Wen-juan; Zhao, Jin-liang; Zhu, Chao-dong; Jiang, Guo-fang

    2010-10-01

    We present the complete mitochondrial DNA sequence of Eupolyphaga sinensis. This closed circular molecule is 15553 bp long and consists of 37 genes that encode for 13 inner membrane proteins, 2 ribosomal RNAs and 22 transfer RNAs. The genome shares the gene order and orientation with previously known Blattaria mitochondrial genomes. All tRNAs could be folded into the typical cloverleaf secondary structure, but the tRNASer (AGN) appears to be missing the DHU arm. The A + T-rich region is 857 bp long and longer than other cockroaches. Based on the concatenated amino acid sequences of all protein coding genes of E. sinensis in conjunction with those 23 other arthropod sequences, we reconstruct the phylogenetic tree. Phylogenetic analyses shows that Blataria (including Isoptera) and the Mantodea are sister groups. Furthermore the relationship of the three basal clades of winged insects are different from the three previous hypotheses ((Ephemeroptera + Odonata) +Neoptera, Ephemeroptera + (Odonata + Neoptera), Odonata + (Ephemeroptera +Neoptera)). The Ephemeroptera (Parafronurus youi) clusters with the Plecoptera (Pteronarcys princes). PMID:20012368

  6. Mathematical modelling of wood and briquettes torrefaction

    Energy Technology Data Exchange (ETDEWEB)

    Felfli, Felix Fonseca; Luengo, Carlos Alberto [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Grupo Combustiveis Alternativos; Soler, Pedro Beaton [Universidad de Oriente, Santiago de Cuba (Cuba). Fac. de Ingenieria Mecanica. Centro de Estudios de Eficiencia Energetica; Rocha, Jose Dilcio [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE)

    2004-07-01

    A mathematical model valid for the torrefaction of wood logs and biomass briquettes is presented. The model described both chemical and physical processes, which take place in a moist piece of wood heated at temperatures between 503 and 573 K. Calibration measurements of the temperature profile and mass loss, were performed on dry cylinders of wood samples during torrefaction in an inert atmosphere at 503, 533, and 553 K. The calculated data shows a good agreement with experiments. The model can be a useful tool to estimate projecting and operating parameters for torrefaction furnaces such as minimum time of torrefaction, energy consumption and the mass yield. (author)

  7. Light management in flexible glass by wood cellulose coating.

    Science.gov (United States)

    Fang, Zhi-Qiang; Zhu, Hong-Li; Li, Yuan-Yuan; Liu, Zhen; Dai, Jia-Qi; Preston, Colin; Garner, Sean; Cimo, Pat; Chai, Xin-Sheng; Chen, Gang; Hu, Liang-Bing

    2014-01-01

    Ultra-thin flexible glass with high transparency is attractive for a broad range of display applications; however, substrates with low optical haze are not ideal for thin film solar cells, since most of the light will go through the semiconductor layer without scattering, and the length of light travelling path in the active layer is small. By simply depositing a layer of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-oxidized wood fibers (TOWFs), we are able to tailor the optical properties of flexible glass dramatically from exhibiting low haze (glass is investigated. As the average fiber length decreases, the transmission haze of TOWF-coated flexible glass illustrates a decreasing trend. Earth-abundant natural materials for transparent, hazy, and flexible glass have tremendous applicability in the fabrication of flexible optoelectronics with tunable light scattering effects by enabling inexpensive and large-scale processes. PMID:25068486

  8. Coal and wood fuel for electricity production: An environmentally sound solution for waste and demolition wood

    Energy Technology Data Exchange (ETDEWEB)

    Penninks, F.W.M. [EPON, Zwolle (Netherlands)

    1997-12-31

    Waste wood from primary wood processing and demolition presents both a problem and a potential. If disposed in landfills, it consumes large volumes and decays, producing CH{sub 4}, CO{sub 2} and other greenhouse gases. As an energy source used in a coal fired power plant it reduces the consumption of fossil fuels reducing the greenhouse effect significantly. Additional advantages are a reduction of the ash volume and the SO{sub 2} and NO{sub x} emissions. The waste wood requires collection, storage, processing and burning. This paper describes a unique project which is carried out in the Netherlands at EPON`s Gelderland Power Plant (635 MW{sub e}) where 60 000 tonnes of waste and demolition wood will be used annually. Special emphasis is given to the processing of the powdered wood fuel. Therefore, most waste and demolition wood can be converted from an environmental liability to an environmental and economic asset. (author)

  9. Overview of Wood-based Panel Industry in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The production of wood-based panel was presented firstly in this paper. Some features of China’s wood-based panel industry were reviewed, including production bases, raw materials and main markets of wood-based panel. In addition, the trade flow of wood-based panel was described in the end.

  10. An Overview of the Biology of Reaction Wood Formation

    Institute of Scientific and Technical Information of China (English)

    Sheng Du; Fukuju Yamamoto

    2007-01-01

    Reaction wood possesses altered properties and performs the function of regulating a tree's form, but it is a serious defect in wood utility. Trees usually develop reaction wood in response to a gravistimulus. Reaction wood in gymnosperms is referred to as compression wood and develops on the lower side of leaning stems or branches.In arboreal, dicotyledonous angiosperms, however, it is called tension wood and is formed on the upper side of the leaning. Exploring the biology of reaction wood formation is of great value for the understanding of the wood differentiation mechanisms, cambial activity, gravitropism, and the systematics and evolution of plants. After giving an outline of the variety of wood and properties of reaction wood, this review lays emphasis on various stimuli for reaction wood induction and the extensive studies carried out so far on the roles of plant hormones in reaction wood formation. Inconsistent results have been reported for the effects of plant hormones. Both auxin and ethylene regulate the formation of compression wood in gymnosperms. However, the role of ethylene may be indirect as exogenous ethylene cannot induce compression wood formation. Tension wood formation is mainly regulated by auxin and gibberellin. Interactions among hormones and other substances may play important parts in the regulation of reaction wood formation.

  11. Finite Element Analysis Of Boron Diffusion In Wood

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Hoffmeyer, Preben; Bechgaard, Carl;

    2002-01-01

    The coupled heat and mass transfer equations for air, water and heat transfer are supplemented with a conservation equation for an additional species representing the concentration of boron in wood. Boundary conditions for wood-air. wood-soil and wood-boron interfaces arc discussed and finally...

  12. Distributions of the S-matrix poles in Woods-Saxon and cut-off Woods-Saxon potentials

    Science.gov (United States)

    Salamon, P.; Baran, Á.; Vertse, T.

    2016-08-01

    The positions of the l = 0S-matrix poles are calculated in generalized Woods-Saxon (GWS) potential and in cut-off generalized Woods-Saxon (CGWS) potential. The solutions of the radial equations are calculated numerically for the CGWS potential and analytically for GWS using the formalism of Gy. Bencze [1]. We calculate CGWS and GWS cases at small non-zero values of the diffuseness in order to approach the square well potential and to be able to separate effects of the radius parameter and the cut-off radius parameter. In the case of the GWS potential the wave functions are reflected at the nuclear radius therefore the distances of the resonant poles depend on the radius parameter of the potential. In CGWS potential the wave function can be reflected at larger distance where the potential is cut to zero and the derivative of the potential does not exist. The positions of most of the resonant poles do depend strongly on the cut-off radius of the potential, which is an unphysical parameter. Only the positions of the few narrow resonances in potentials with barrier are not sensitive to the cut-off distance. For the broad resonances the effect of the cut-off cannot be corrected by using a suggested analytical form of the first order perturbation correction.

  13. ADHESIVE-FREE WOOD JOINTS – PART I: SESSILE OAK WOOD (Quercus petraea L.)

    OpenAIRE

    Ramona-Elena DUMITRAȘCU

    2015-01-01

    act: Wood as a raw material is indispensable in various human activities. Its investigation is inexhaustible and its responsible valorization, in accordance with current requirements for re-use and subsequent re-integration, is a priority at national level. Rotational friction as an alternative method of joining wood elements or wooden structures has not been addressed in Romania until now, even if it has been under investigation during the past 15 years in the wood field. T...

  14. LCA-based optimization of wood utilization under special consideration of a cascading use of wood.

    Science.gov (United States)

    Höglmeier, Karin; Steubing, Bernhard; Weber-Blaschke, Gabriele; Richter, Klaus

    2015-04-01

    Cascading, the use of the same unit of a resource in multiple successional applications, is considered as a viable means to improve the efficiency of resource utilization and to decrease environmental impacts. Wood, as a regrowing but nevertheless limited and increasingly in demand resource, can be used in cascades, thereby increasing the potential efficiency per unit of wood. This study aims to assess the influence of cascading wood utilization on optimizing the overall environmental impact of wood utilization. By combining a material flow model of existing wood applications - both for materials provision and energy production - with an algebraic optimization tool, the effects of the use of wood in cascades can be modelled and quantified based on life cycle impact assessment results for all production processes. To identify the most efficient wood allocation, the effects of a potential substitution of non-wood products were taken into account in a part of the model runs. The considered environmental indicators were global warming potential, particulate matter formation, land occupation and an aggregated single score indicator. We found that optimizing either the overall global warming potential or the value of the single score indicator of the system leads to a simultaneous relative decrease of all other considered environmental impacts. The relative differences between the impacts of the model run with and without the possibility of a cascading use of wood were 7% for global warming potential and the single score indicator, despite cascading only influencing a small part of the overall system, namely wood panel production. Cascading led to savings of up to 14% of the annual primary wood supply of the study area. We conclude that cascading can improve the overall performance of a wood utilization system. PMID:25660355

  15. Comparative LCA of Wood from Conventional Forestry and Wood from Short Rotation Coppice

    OpenAIRE

    Kunstmann, Martin

    2014-01-01

    Worldwide there is an increasing demand of natural resources. In future, non renewable resources get substituted by renewable resources in the energetic sector as well as in the material sector. That implies a stronger usage of renewable resources especially - wood. In 2009 there was a usage of 77 million cubic meters of wood for material applications and a quantity of 55 million cubic meters for energetic applications in Germany alone. Furthermore, there is an increasing demand on wood for e...

  16. A geographical analysis of the Swedish wood fuel market

    International Nuclear Information System (INIS)

    The geographical variation in Swedish wood fuel market characteristics for the district heating sector has been studied using Geographical Information Systems (GIS) and cross-sectional Tobit analysis. The results indicate that local availability and competition for wood fuels influence the wood fuel consumption at inland heating plants. The factors affecting the decision to use wood fuel at heating plants close to seaports, however, were not captured by the model, suggesting that coastal location reduces dependency on the local wood fuel market. The effects of changes in local wood fuel availability on wood fuel use by an inland heating plant are presented and discussed

  17. A comprehensive multilocus phylogeny for the wood-warblers and a revised classification of the Parulidae (Aves)

    Science.gov (United States)

    Lovette, I.J.; Perez-Eman, J. L.; Sullivan, J.P.; Banks, R.C.; Fiorentino, I.; Cordoba-Cordoba, S.; Echeverry-Galvis, M.; Barker, F.K.; Burns, K.J.; Klicka, J.; Lanyon, S.M.; Bermingham, E.

    2010-01-01

    The birds in the family Parulidae-commonly termed the New World warblers or wood-warblers-are a classic model radiation for studies of ecological and behavioral differentiation. Although the monophyly of a 'core' wood-warbler clade is well established, no phylogenetic hypothesis for this group has included a full sampling of wood-warbler species diversity. We used parsimony, maximum likelihood, and Bayesian methods to reconstruct relationships among all genera and nearly all wood-warbler species, based on a matrix of mitochondrial DNA (5840 nucleotides) and nuclear DNA (6 loci, 4602 nucleotides) characters. The resulting phylogenetic hypotheses provide a highly congruent picture of wood-warbler relationships, and indicate that the traditional generic classification of these birds recognizes many non-monophyletic groups. We recommend a revised taxonomy in which each of 14 genera (Seiurus, Helmitheros, Mniotilta, Limnothlypis, Protonotaria, Parkesia, Vermivora, Oreothlypis, Geothlypis, Setophaga, Myioborus, Cardellina, Basileuterus, Myiothlypis) corresponds to a well-supported clade; these nomenclatural changes also involve subsuming a number of well-known, traditional wood-warbler genera (Catharopeza, Dendroica, Ergaticus, Euthlypis, Leucopeza, Oporornis, Parula, Phaeothlypis, Wilsonia). We provide a summary phylogenetic hypothesis that will be broadly applicable to investigations of the historical biogeography, processes of diversification, and evolution of trait variation in this well studied avian group. ?? 2010 Elsevier Inc.

  18. 信阳市蟑螂密度监测及侵害现况的调查研究%Investigation and research on the density of cockroaches and disoperation in Xinyang City

    Institute of Scientific and Technical Information of China (English)

    刘淑华; 方世民; 徐威; 张英

    2012-01-01

    目的 了解信阳市蟑螂种类、密度、季节消长情况,为信阳市消灭蟑螂提供科学依据.方法 用粘捕法进行调查.结果 在各类环境中共捕获蟑螂1 328只,其中德国小蠊1 193只,美洲大蠊135只,平均侵害率为7.36%,密度为0.65只/张.结论 德国小蠊为优势种群,活动高峰在夏秋季,宾馆和餐饮单位密度较高,应加强蟑螂监测和防制工作.%Objective To understand the type, density and seasonal fluctuation of cockroach in Xinyang City and provide scientific basis for the elimination of cockroach. Method Sticky traps method. Results We had captured 1 328 cockroaches in all kinds of environments, among which 1 193 were blattella germanica and 135 were periplaneta americana. The average disoperation rate was 7. 36% , and the density was 0. 65 cockroach per piece of paper. Conclusions Blattella germanica was the predominant species, and was active in summer and autumn. There were high density of cockroaches in hotels and restaurants, therefore, this units should strengthen the monitor and control of cockroach.

  19. 远洋船蟑螂密度调查及其杀灭效果观察%The density monitor and efficacy of controlling cockroaches on ocean-going ships

    Institute of Scientific and Technical Information of China (English)

    王育兵; 严峥; 夏本立; 尹莉; 王武芳; 郭鹏; 石静; 巩立; 许晓华

    2011-01-01

    Objective To monitor the density, discriminate the species and observe efficacy of controlling cockroaches using a set of insecticides on two ocean-going ships. Methods Observing the density by the method of adhibiting ,then making a discriminationg for its pecies. Using a set of insecticides which were composed of granular bait and gel bait to decrease the density of cockroaches. Results The density of cockroaches were 1.06 and 2.39 pieces per piece per night respectively, all the cockroaches adhibited were Blattella germanica. After using insecticides for seven days,the average density of cockroaches declined by 87.03%. The density declined by 94.14% after three months. Conclusion The methed of using a set of insecticides could get an ideal effect against cockroaches,which is worth popularizing on ships.%目的 了解远洋船上嶂螂种群、密度,观察套餐法在远洋船上杀灭嶂螂的效果.方法 用粘捕法进行蟑螂密度调查,对粘捕到的嶂螂进行种类鉴定,采用套餐法对远洋船上蟑螂进行现场杀灭试验.结果 甲、乙两船饮食场所的蟑螂密度分别为1.06和2.39只/(张·夜);嶂螂的优势种群为德国小蠊;投药后1周嶂螂密度下降率为87.03%,3个月后嶂螂密度下降率达94.14%.结论 远洋船上采用套餐法灭蟑值得推广.

  20. Effects of Mixing Temperature and Wood Powder Size on Mechanical Properties of Wood Plastic Recycled Composite

    Science.gov (United States)

    Miki, Tsunehisa; Sugimoto, Hiroyuki; Kojiro, Keisuke; Kanayama, Kozo; Yamamoto, Ken

    In this study, wood (cedar) powder ranging from 53 µm to 1 mm sizes, recycled polypropylene (PP) / polyethylene (PE) and acid-modified PP as a compatibilization agent were used to produce a wood-plastic recycled composite (WPRC). For discussing the effects of the wood powder sizes on the mechanical properties of the WPRC, a mixing process of the wood powder and the plastics in a constant wood content of 50% weight was firstly performed by a mixing machine controlled temperature and rotation of mixing blade. And then, to obtain WPRC panels the wood and plastics mixtures were compressed in a mould under a constant pressure and a temperature for a certain holding time. WPRC specimens for mechanical tests were cut from the WPRC panels, and a tensile strength and a size-stability were acquired. The results show that the successful mixing process runs above 180°C, where the mixing torque required compounding keeps constant or slightly increases. The tensile strength of the WPRC increases when the smaller size of wood powder is used for wood/plastic compound under successful mixing conditions. It is shown from thickness change rate of specimens that mixing temperature of wood/plastic compound affects a size stability of the WPRC.

  1. On the formaldehyde release of wood particles

    OpenAIRE

    Roffael, E.; Behn, C.; Dix, B.

    2012-01-01

    The emission of formaldehyde from softwood particles, as measured by the flask method (EN 717-3), depends highly on the particle size. Therefore, no definite value for the formaldehyde release from wood can be given.

  2. Wood recognition using image texture features.

    Directory of Open Access Journals (Sweden)

    Hang-jun Wang

    Full Text Available Inspired by theories of higher local order autocorrelation (HLAC, this paper presents a simple, novel, yet very powerful approach for wood recognition. The method is suitable for wood database applications, which are of great importance in wood related industries and administrations. At the feature extraction stage, a set of features is extracted from Mask Matching Image (MMI. The MMI features preserve the mask matching information gathered from the HLAC methods. The texture information in the image can then be accurately extracted from the statistical and geometrical features. In particular, richer information and enhanced discriminative power is achieved through the length histogram, a new histogram that embodies the width and height histograms. The performance of the proposed approach is compared to the state-of-the-art HLAC approaches using the wood stereogram dataset ZAFU WS 24. By conducting extensive experiments on ZAFU WS 24, we show that our approach significantly improves the classification accuracy.

  3. Moisture-driven fracture in solid wood

    DEFF Research Database (Denmark)

    Larsen, Finn; Ormarsson, Sigurdur; Olesen, John Forbes

    2011-01-01

    Moisture-induced fractures in solid timber create considerable problems for both building industries and sawmills. Cracks caused by kiln-drying of solid timber are extremely difficult to predict. This paper reports on experiments concerned with methods of reducing cracks in wood and with the crac......Moisture-induced fractures in solid timber create considerable problems for both building industries and sawmills. Cracks caused by kiln-drying of solid timber are extremely difficult to predict. This paper reports on experiments concerned with methods of reducing cracks in wood...... process, suggesting that sealing the ends of timber logs while in the green moisture state could considerably reduce the development of end-cracks. The initial moisture content and the shrinkage properties of the wood varied markedly from pith to bark. The importance of taking material inhomogeneities...... into account when modelling crack propagation in solid wood is emphasized. © 2011 Taylor & Francis....

  4. Wood ethanol and synthetic natural gas pathways

    International Nuclear Information System (INIS)

    This report provided details of updates to the wood ethanol pathway recently added to the GHGenius model, an analytical tool used to analyze emissions from conventional and alternative fuel combustion processes. The pathway contains data developed by the United States Department of Energy. A number of co-products were added to the wood and agricultural residue pathways, including furfural, xylitol, lignin, and glycerol. New chemical inputs included nitrogen gas, ammonia, enzymes and yeast. Biological ethanol pathways were reviewed, and separate inputs for wood, agricultural residues, corn ethanol, and wheat ethanol were added. The model was updated to reflect current research conducted on the gasification of wood and the upgrading of the gas to produce pipeline quality natural gas. New process developments in producing pipeline quality gas from coal were also added. The ability to model enzyme consumption was added to all ethanol pathways. 25 refs., 41 tabs., 8 figs

  5. Supply of Rubber Wood Log in Malaysia

    Directory of Open Access Journals (Sweden)

    A. W. Noraida

    2014-06-01

    Full Text Available Issue on shortage of raw material for wood processing solved by discovery of rubber wood log as one of the substitutes the natural log. This paper examines the supply of rubber wood log in Malaysia. We employ ARDL Bound Approach Test and time series data from 1980 to 2010 which represented the whole Malaysia are used to achieve the established objectives. The result shown, in the long run harvested area and wages have 1% and 10% significant level respectively. While in the short run, there was only harvested area having an impact with 1% significant level. This result indicates that, the harvested area become the most impact towards supply of rubber wood log either in short run or in the long run. While wages as input cost gave less impact in another word it become unburden to the producers.

  6. Wood ethanol and synthetic natural gas pathways

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-11-30

    This report provided details of updates to the wood ethanol pathway recently added to the GHGenius model, an analytical tool used to analyze emissions from conventional and alternative fuel combustion processes. The pathway contains data developed by the United States Department of Energy. A number of co-products were added to the wood and agricultural residue pathways, including furfural, xylitol, lignin, and glycerol. New chemical inputs included nitrogen gas, ammonia, enzymes and yeast. Biological ethanol pathways were reviewed, and separate inputs for wood, agricultural residues, corn ethanol, and wheat ethanol were added. The model was updated to reflect current research conducted on the gasification of wood and the upgrading of the gas to produce pipeline quality natural gas. New process developments in producing pipeline quality gas from coal were also added. The ability to model enzyme consumption was added to all ethanol pathways. 25 refs., 41 tabs., 8 figs.

  7. Measuring Prevention More Broadly, An Empirical...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Measuring Prevention More Broadly, An Empirical Assessment of CHIPRA Core Measures Differences in CHIP design and structure, across states and over time, may limit...

  8. China s Wood Industry after Joining WTO

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    After reviewing the present status and prospects of wood industry in the world, the author suggests that in response to the new situation of economic globalization and China's entry into the WTO, the Chinese wood industry should further develop IT application, optimize and upgrade industrial structure and raise quality of labor force, blazing a new trail to industrialization featuring high scientific and technological content, good economic return, low resources consumption, little environmental polluti...

  9. Waste-Wood-Derived Fillers for Plastics

    OpenAIRE

    English, Brent; Clemons, Craig M.; Stark, Nicole; Schneider, James P.

    1996-01-01

    Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts. Such thermoplastics are usually provided to the end-user as a precompounded, pelletized feedstock. Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper fiber, are also effective as fillers. The goal of this project was to generate commercial interest in using waste-wood–paper-...

  10. Market opportunities for the utilization of wood waste generated by small sawmills

    International Nuclear Information System (INIS)

    Analysis of the amounts and types of wood residue from the British Columbia sawmill and logging industry shows that only ca 50% of the residue is being utilized. On a large scale, increased utilization will mainly be achieved through use for the generation of energy. For small sawmills, a more innovative approach to the problem is needed. To assist in developing the innovative markets and uses for wood residues from the small mills, a series of in-depth interviews was conducted with sawmill operators, resource agencies, and users of wood residue throughout British Columbia. The user markets include other sawmills; pulp, paper, and particleboard plants; energy applications; and agriculture. The results of the interviews are tabulated and analyzed to demonstrate the broad spectrum of wood residue uses currently available as well as those that are emerging. For many small sawmill operations in remote areas, utilization of residues is not economical. As environmental regulations become more stringent, the cost and difficulty of handling or disposing residue will increase, and utilization (even if not economical) will become a valid option compared to disposal. A number of emerging markets for wood residue are noted, many of which are in the agricultural field. Other products which can be made out of wood residues are hog fuel and fuel pellets or briquettes. Small sawmills will not have the residue volumes or funds to establish a briquette plant, but they have expressed interest in supplying residue to any such plant that can be established in their area. 16 refs., 5 figs., 3 tabs

  11. Adsorption of coper-ethanolamine preservatives in wood

    OpenAIRE

    Humar, Miha

    2008-01-01

    Copper-ethanolamine based preservatives are one of the most important wood preservatives for protection of wood in third and fourth use class. Despite the fact that they are commercially used for several years, complete mechanismof fixation in wood has been not resolved to date. It is clear that copper-ethanolamine system reacts with wood faster than copper-chromium based wood preservatives. It is not known, however, which parameters control this process of fixation and when it is finished. I...

  12. Dynamic Mechanical Properties of Wood Powder /Polypropylene Composites

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The dynamic mechanical properties of wood powder/polypropylene composites with different wood content treated and untreated with the compatibilizer have been studied. It has been found that addition of wood powders and the compatibilizer can both improve the viscoelasticity of composites. Glass transition temperature (Tg) of appropriate wood powder-filled composites decreased. The value for the storage modulus (G') increased gradually with increasing wood powder content. The addition of the compatibiliz...

  13. Effect of Wood Particle Size on the Properties of Wood/Polypropylene Composites Ⅰ:Mechanical Properties

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The mechanical properties of wood powder/polypropy!ene composites with different wood particle sizes and wood species have been studied. All of the wood particie sizes increased the E-modulus of the composites. Tensile tests showed that wood partide sizes had a negative effect on the elongation at break and the tensile strength of the composites has been improved when wood particle sizes were be(ow 150 μm (below 100 mesh). For the impact tests, the wood partide sizes had a negative effect, but the MDF f...

  14. Wood zone plate fishnet metalens

    Directory of Open Access Journals (Sweden)

    Orazbayev Bakhtiyar

    2015-01-01

    Full Text Available Fresnel-zone plate lenses provide focusing performance while having low profile. Unfortunately, they usually display higher reflection losses than conventional dielectric lenses. Here, we demonstrate a low-profile Wood zone plate metalens based on the fishnet metamaterial working in a near-zero regime with an equivalent refractive index less than unity (nf = 0.51. The metalens is made of alternating dielectric and fishnet metamaterial concentric rings. The use of fishnet metamaterial allows reducing the reflections from the lens, while maintaining low profile, low cost and ease of manufacturing. The lens is designed to work at the W-band of the millimeter-waves range with a focal length FL = 22.8 mm (7.5 λ0 aiming at antenna or radar system applications. The focusing performance of the lens along with its radiation characteristics in a lens antenna configuration have been studied numerically and confirmed experimentally, showing a gain improvement of ~2.5 dB with respect to a fishnet Soret metalens.

  15. Short rotation Wood Crops Program

    Energy Technology Data Exchange (ETDEWEB)

    Wright, L.L.; Ehrenshaft, A.R.

    1990-08-01

    This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program for the year ending September 30, 1989. The primary goal of this research program, sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division, is the development of a viable technology for producing renewable feedstocks for conversion to biofuels. One of the more significant accomplishments was the documentation that short-rotation woody crops total delivered costs could be $40/Mg or less under optimistic but attainable conditions. By taking advantage of federal subsidies such as those offered under the Conservation Reserve Program, wood energy feedstock costs could be lower. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. 8 figs., 20 tabs.

  16. Flt3-L Increases CD4+CD25+Foxp3+ICOS+ Cells in the Lungs of Cockroach-Sensitized and -Challenged Mice

    OpenAIRE

    McGee, Halvor S; Edwan, Jehad H.; Devendra K Agrawal

    2009-01-01

    We previously reported in an ovalbumin-induced model of allergic asthma that Fms-like tyrosine kinase 3 ligand (Flt3-L) reversed airway hyperresponsiveness (AHR) and airway inflammation, and increased the number of regulatory CD11chighCD8αhighCD11blow dendritic cells in the lung. In this study, we investigated the effect of Flt3-L in a clinically relevant aeroallergen-induced asthma on the phenotypic expression of lung T cells. Balb/c mice were sensitized and challenged with cockroach antigen...

  17. Plasma-chemical surface engineering of wood

    Directory of Open Access Journals (Sweden)

    A. Sokołowska

    2009-12-01

    Full Text Available Purpose: Wood infiltrated with nano-silica hydrosol forms a “weak”, irregular composite of components bound with hydrogen bonds only. The purpose of this study was to investigate the influence of low-energy ions bombardment on the structure and properties of the surface of this composite. The aim of these investigations was to produce a shallow “buried” layer of a dense wood-ceramic composite on a wood surface .Design/methodology/approach: D.c. glow-discharge in N2/H2 (9:11 atmosphere under a pressure of 4hPa was the source of ions. A beech plate was placed on the cathode. The temperature of wood was 200°C. The material collected from the wood-silica composite surface was investigated with FTIR spectroscopy and SEM observations. The surface energy was determined with the use of contact angle measurements.Findings: The ions influenced silica only. The nano-particles underwent sintering changing its medium size twice and a small I.R. peak of N2 trapped in SiO2 suggest the possibility of silica nitriding. A buried, continual surface layer of sintered silica did not form. The surface energy of the “wood-silica” plate was slightly decreased after plasma treatment.Research limitations/implications: The results proved the possibility of plasma treatment of wood even in a d.c. glow-discharge under low pressure. Silica sintering, a difficult process which in a thermal way has to be carried out at a temperature of 1000°C, taking place in a plasma at a temperature of 200°C showed the very special nature of an influence of ions.Originality/value: The plasma surface treatment of wood in the d.c. glow-discharge (GD under reduced pressure has not been investigated. There are only publications about glow-dielectric-barrier-discharge (GDBD at atmospheric pressure applications for wood surface modification. The energy of ions in GDBD is much smaller than that of ions in GD and therefore the application of glow discharge under reduced pressure to

  18. Monitoring of cockroach density and seasonal fluctuation in Haikou City%2009~2010年海口市蟑螂种群密度及季节消长监测结果

    Institute of Scientific and Technical Information of China (English)

    王晓花; 陈永薇

    2011-01-01

    目的 了解海口市蟑螂种类、密度、季节消长情况,为海口市的蟑螂防治提供科学依据.方法 采用粘捕法分别在居民住宅、餐饮、宾馆、农贸市场和医院等不同环境中进行蟑螂种群分布、密度、季节消长情况调查.结果 海口市蟑螂种群有德国小蠊、美洲大蠊、澳洲大蠊和斑蠊,其中德国小蠊为海口市的优势种群.海口市区蟑螂密度较高[4],全年平均达到2.76只/张,栖息场所蟑螂密度以餐饮业密度最高,达5.86只/张,宾馆次之,达3.26只/张,农贸市场、医院和居民较低,分别为1.16只/张、0.55只/张、0.34只/张.蟑螂一年四季均有活动,8月份蟑螂密度最高,1月份蟑螂密度最低.结论 海口市蟑螂种群发生了明显变化,尤其是德国小蠊侵害严重,应加强蟑螂密度和抗药性等监测,根据监测结果,及时预警预报,提出科学合理的防治措施.%Objective To survey the cockroach species,the density and the seasonal fluctuation and provide scientific basis for elimination cockroach in Haikou. Methods The population distribution,density and seasonal flunctuation of cockroach were suveyed using night sticky trap method in residential areas,hotels,eating houses,markets and hospitals. Results There were four cockroachs species in Haikou:the German cockroach,the American cockroach,the Australian cockroach and the Neostylopyga rhombifolia. The German cockroach was predominant. The cockroach density was high with average density of 2.76/nights and the numbers of cockroadch in eating houses,hotel,market,hospital,residential areas were 5.86/ night,3.26/night, 1.16/night,0.55/night and 0.34/night. The cockroach density was the highest in August and the lowest in January. Conclusion The population and density of cockroach in Haikou varied and integrated monitoring and eliminating measures be adopted to control the pervalence of cockroad.

  19. 集贸市场蜚蠊侵害和抗药性调查及综合防制研究%Infestation and pesticide resistance of cockroaches in market and relevant comprehensive control measures

    Institute of Scientific and Technical Information of China (English)

    邓丽娟; 刘迪; 刘小泉; 刘俊

    2013-01-01

    Objective To investigate the infestation and population distribution of cockroaches in the market and the pesticide resistance of Blattella germanica to provide a basis for comprehensive control measures. Methods The infestation of cockroaches was investigated by visual inspection; the density of cockroaches was measured by cockroach glue board; the pesticide resistance of B. Germanica was determined by residual film method. The pesticides to which the cockroaches were sensitive were used for comprehensive control. Results The infestation rate of cockroaches in the market was 86.67%, and the density was 4.19 cockroaches/board/night. The levels of resistance (folds) of 6. Germanica to beta-cypermethrin, deltamethrin, propoxur, chlorpyrifos, dimethyl dichloroviny phosphate (DDVP), cypermethrin, permethrin, tetramethrin, and azamethiphos were 2.65, 3.82, 1.77, 3.51, 11.19, 5.21, 6.51, 12.00, and 2.11, respectively. The pesticides to which the cockroaches were sensitive and developed low resistance achieved a killing rate of 96.19%. Conclusion There is a high infestation rate of cockroaches in the market of Wuhan city, China. B. Germanica is the dominant species of the cockroaches and has developed high resistance to DDVP and tetramethrin. Comprehensive control measures, including environmental treatment and pesticide use, should be taken to control the density of cockroaches below a harmless level.%目的 了解集贸市场蜚蠊侵害情况、种群分布及德国小蠊的抗药性,为制定防制对策提供依据.方法 采用目测法调查蜚蠊侵害情况,用粘蟑板测定其密度,用药膜接触法测定抗药性,采用敏感和低抗的药物进行综合防制.结果 集贸市场蜚蠊侵害率为86.67%,密度为4.19只/(张·夜);德国小蠊对高效氯氰菊酯、溴氰菊酯、残杀威、毒死蜱、敌敌畏、氯氰菊酯、氯菊酯、胺菊酯、甲基吡(嗯)磷9种杀虫剂的抗药性分别为2.65、3.82、1.77、3.51、11.19、5.21、6.51

  20. Tissue damage after acute intoxication by polychlorinated biphenyls (PCBs in cockroaches Blattella germanica

    Directory of Open Access Journals (Sweden)

    S Lambiase

    2009-06-01

    Full Text Available It is common knowledge that polychlorinated biphenyls (PCBs represent a serious threat to the health of both vertebrates and invertebrates. As far as the former are concerned, especially as regards human beings, a broad literature describes the direct and indirect effects induced by the PCBs on their systems and organs. Among invertebrates, the information available is mostly related to arthropods and is, however, very scarce. The aim of this work was to evaluate the effects of polychlorinated biphenyls (PCBs on tissues and organs of individuals belonging to a species of Blattaria (Blattella germanica treated with various doses of this toxic material. The pathologies found became more serious as the dosage increased and were present throughout the entire digestive system, in the fat body and in the male gonads: in these areas cell and tissue breakdown and severely damaged spermiogenesis were observed. In particular, the testicles, Malpighian tubules and fat body accumulated an amorphous basophilic PAS-positive substance. Furthermore, the NOS-dependent NADPH diaphorase activity pattern in the retina and optic lobes was more evident in the treated than in the control insects.

  1. Cockroaches (periplaneta americana and blattella germanica: reservoirs of multi drug resistant (MDR bacteria in Uyo, Akwa Ibom State

    Directory of Open Access Journals (Sweden)

    E.P. Udoinyang

    2012-08-01

    Full Text Available Bacteriological examination of external surfaces and internal guts of Periplaneta americana and Blattela germanica were carried out using standard method and antibiotics susceptibility profiles of the isolates were determined using disc diffusion methods. Of the 317 bacteria isolated from the external surfaces and internal guts of P. americana, 275 (86.8% were Gram-negative bacilli, while 42 (13.2% were Gram-positive bacteria. Of the 204 bacterial isolates from B. germanica, 175 (85.8% were Gram negative, while 29 (14.2% were Gram positive bacteria. The bacteria isolated were Salmonella spp, Shigella spp, Staphylococcus aureus, coagulase negative Staphylococcus spp, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Citrobacter freundii, Morganella morganii, Proteus vulgaris, Proteus mirabilis, Enterobacter cloacae and Providencia spp. Among the Gram positive bacteria, only 75.8% S. aureus and 76.5% B. cereus were sensitive to Streptomycin and Gentamycin, while their resistance profiles to antibiotics in decreasing order were as follows: Chloramphenicol (41.7%, Amoxicillin (40.3%, Streptomycin (36.1%, Tetracycline (36.0%, Erythromycin (35.5%, Gentamicin (34.0%, Penicillin (34.6%, Cephalothin (27.8%, Sulfamethoxazole (23.4%, Ciprofloxacin (18.4% and Levofloxacin (17.7%. Less than 50% of E. cloacae and Providencia spp were resistant to Streptomycin, while ˂ 40% of P. vulgaris, K. pneumoniae, and P. aeruginosa were resistant to Chloramphenicol. Of the 353 (67.8% multi drug resistant bacteria, 121 (23.2% were resistant to 3 antibiotics, 232 (65.7% were resistant to 4-10 antibiotics. The antibiotic resistant Salmonella spp. and P. mirabilis had Multiple Antibiotic Resistance (MAR indexes ranging from 0.27 to 0.82. These findings suggest cockroaches in Uyo as potential vectors of medically important multiple drug-resistant bacteria.

  2. Distribution of serotonergic and dopaminergic nerve fibers in the salivary gland complex of the cockroach Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Kühnel Dana

    2002-06-01

    Full Text Available Abstract Background The cockroach salivary gland consists of secretory acini with peripheral ion-transporting cells and central protein-producing cells, an extensive duct system, and a pair of reservoirs. Salivation is controled by serotonergic and dopaminergic innervation. Serotonin stimulates the secretion of a protein-rich saliva, dopamine causes the production of a saliva without proteins. These findings suggest a model in which serotonin acts on the central cells and possibly other cell types, and dopamine acts selectively on the ion-transporting cells. To examine this model, we have analyzed the spatial relationship of dopaminergic and serotonergic nerve fibers to the various cell types. Results The acinar tissue is entangled in a meshwork of serotonergic and dopaminergic varicose fibers. Dopaminergic fibers reside only at the surface of the acini next to the peripheral cells. Serotonergic fibers invade the acini and form a dense network between central cells. Salivary duct segments close to the acini are locally associated with dopaminergic and serotonergic fibers, whereas duct segments further downstream have only dopaminergic fibers on their surface and within the epithelium. In addition, the reservoirs have both a dopaminergic and a serotonergic innervation. Conclusion Our results suggest that dopamine is released on the acinar surface, close to peripheral cells, and along the entire duct system. Serotonin is probably released close to peripheral and central cells, and at initial segments of the duct system. Moreover, the presence of serotonergic and dopaminergic fiber terminals on the reservoir indicates that the functions of this structure are also regulated by dopamine and serotonin.

  3. Functional effects of TGF-β1 on mesenchymal stem cell mobilization in cockroach allergen-induced asthma.

    Science.gov (United States)

    Gao, Peisong; Zhou, Yufeng; Xian, Lingling; Li, Changjun; Xu, Ting; Plunkett, Beverly; Huang, Shau-Ku; Wan, Mei; Cao, Xu

    2014-05-15

    Mesenchymal stem cells (MSCs) have been suggested to participate in immune regulation and airway repair/remodeling. TGF-β1 is critical in the recruitment of stem/progenitor cells for tissue repair, remodeling, and cell differentiation. In this study, we sought to investigate the role of TGF-β1 in MSC migration in allergic asthma. We examined nestin expression (a marker for MSCs) and TGF-β1 signaling activation in airways in cockroach allergen extract (CRE)-induced mouse models. Compared with control mice, there were increased nestin(+) cells in airways and higher levels of active TGF-β1 in serum and p-Smad2/3 expression in lungs of CRE-treated mice. Increased activation of TGF-β1 signaling was also found in CRE-treated MSCs. We then assessed MSC migration induced by conditioned medium from CRE-challenged human epithelium in air/liquid interface culture in Transwell assays. MSC migration was stimulated by epithelial-conditioned medium, but was significantly inhibited by either TGF-β1-neutralizing Ab or TβR1 inhibitor. Intriguingly, increased migration of MSCs from blood and bone marrow to the airway was also observed after systemic injection of GFP(+) MSCs and from bone marrow of Nes-GFP mice following CRE challenge. Furthermore, TGF-β1-neutralizing Ab inhibited the CRE-induced MSC recruitment, but promoted airway inflammation. Finally, we investigated the role of MSCs in modulating CRE-induced T cell response and found that MSCs significantly inhibited CRE-induced inflammatory cytokine secretion (IL-4, IL-13, IL-17, and IFN-γ) by CD4(+) T cells. These results suggest that TGF-β1 may be a key promigratory factor in recruiting MSCs to the airways in mouse models of asthma. PMID:24711618

  4. Agonist actions of clothianidin on synaptic and extrasynaptic nicotinic acetylcholine receptors expressed on cockroach sixth abdominal ganglion.

    Science.gov (United States)

    Thany, Steeve H

    2009-11-01

    Clothianidin is new neonicotinoid insecticide acting selectively on insect nicotinic acetylcholine receptors (nAChRs). Its effects on nAChRs expressed on cercal afferent/giant interneuron synapses and DUM neurons have been studied using mannitol-gap and whole-cell patch-clamp techniques, respectively. Bath-application of clothianidin-induced dose-dependent depolarizations of cockroach cercal afferent/giant interneuron synapses which were not reversed after wash-out suggesting a strong desensitization of postsynaptic interneurons at the 6th abdominal ganglion (A6). Clothinidin activity on the nerve preparation was characterized by an increased firing rate of action potentials which then ceased when the depolarization reached a peak. Clothianidin responses were insensitive to all muscarinic antagonists tested but were blocked by co-application of specific nicotinic antagonists methyllicaconitine, alpha-bungarotoxin and d-tubocurarine. In a second round of experiment, clothianidin actions were tested on DUM neurons isolated from the A6. There was a strong desensitization of nAChRs which was not affected by muscarinic antagonists, pirenzepine and atropine, but was reduced with nicotinic antagonist alpha-bungarotoxin. In addition, clothianidin-induced currents were completely blocked by methyllicaconitine suggesting that (1) clothianidin acted as a specific agonist of nAChR subtypes and (2) a small proportion of receptors blocked by MLA was insensitive to alpha-bungarotoxin. Moreover, because clothianidin currents were blocked by d-tubocurarine and mecamylamine, we provided that clothianidin was an agonist of both nAChRs: imidacloprid-sensitive nAChR1 and -insensitive nAChR2 subtypes. PMID:19583978

  5. Climate effects of wood used for bioenergy

    Energy Technology Data Exchange (ETDEWEB)

    Ros, Jan P.M.; Van Minnen, Jelle G. [Netherlands Environmental Assessment Agency PBL, Bilthoven (Netherlands); Arets, Eric J.M.M. [Alterra, Wageningen University WUR, Wageningen (Netherlands)

    2013-08-15

    Wood growth and natural decay both take time, and this is an important aspect of sustainability assessments of wood used for energy. Wood taken from forests is a carbon-neutral energy source in the long term, but there are many examples of potential sources of wood used for bioenergy for which net emission reductions are not achieved in 10 to 40 years - the time frame for most climate policy mitigation targets. This is caused by two factors. The first factor relates to the fact that the carbon cycles of wood have a long time span. After final felling, CO2 fixation rates are initially relatively low, but increase again as forests regrow. This regrowth takes many years, sometimes more than a century. Wood residues can either be used or left in the forest. By using them, the emissions from the otherwise decaying residues (taking 2 to 30 years) would be avoided. The second factor concerns the fact that, if the wood is used for bioenergy, then fossil energy emissions are being avoided. However, the direct emission levels from bioenergy are higher than those related to the fossil energy it replaces. These additional emissions also have to be compensated. The carbon debt caused by both factors has to be paid back first, before actual emission reductions can be realised. For wood residues (from harvesting or thinning) that are used to replace coal or oil products, these payback times are relatively short, of the order of 5 to 25 years, mainly depending on location and type of residue (longer if they replace gas). This is also the case when using wood from salvage logging. In most cases, when using wood from final felling directly for energy production, payback times could be many decades to more than a century, with substantial increases in net CO2 emissions, in the meantime. This is especially the case for many forests in Europe, because they are currently an effective carbon sink. Additional felling reduces average growth rates in these forests and thus the sequestration

  6. POLYPYRROLE AND POLYPYRROLE/WOOD-DERIVED MATERIALS CONDUCTING COMPOSITES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Davide Beneventi Mail

    2011-07-01

    Full Text Available Wood and cellulose derivatives, in both fibrous and water-soluble macromolecular form, are emerging as outstanding candidates for organic electronics applications due to their large-scale availability, low cost, and easy processability. Paper and wood fibre-based derivatives are considered to be materials of choice as supports for communication world-wide. The interest in producing inexpensive and universally available conducting polymer/cellulose fibres substrates resides in the possibility of creating new materials that can be used for a broad range of advanced applications. For instance, PPy/cellulose fibres composites can be used for the preparation of energy storage devices thanks to the conjugation of the high specific area of cellulose fibres and the electrochemical properties of PPy. Other possible applications of such composites are in the area of the antistatic materials, sensors, electromagnetic interference shielding materials, smart packaging, and tissues. Concerning the woody polymers, some of them (i.e. cellulose derivatives also exhibit biocompatibility, as well as film-forming properties and transparency. In combination with the electrical properties of PPy, these features make PPy/macromolecular cellulose composites suitable for applications as displays, lighting, and photovoltaics. Due to their chemical structure, macromolecular wood derivatives have been proposed with success as enhancing conductivity additives in Py polymerisation. The aim of the present review is to provide an overview of PPy chemistry and of the most relevant advances attained in the production of PPy/wood derived materials conducting composites.

  7. Exposure to wood dust and endotoxin in small-scale wood industries in Tanzania.

    NARCIS (Netherlands)

    Rongo, L.M.B.; Msamanga, G.I.; Burstyn, I.; Barten, F.J.M.H.; Dolmans, W.M.V.; Heederik, D.

    2004-01-01

    Workers in small-scale wood industries (SSWI) have increased risks of developing asthma and other respiratory diseases. Wood dust and microbial agents have both been suggested to play a role, but few studies have measured endotoxin exposure in SSWI in Africa. We assessed inhalable dust levels in 281

  8. Service Life Prediction of Wood Claddings by in-situ Measurement of Wood Moisture Content

    DEFF Research Database (Denmark)

    Engelund, Emil Tang; Lindegaard, Berit; Morsing, Niels

    2009-01-01

    of wood moisture are done by in-situ resistance moisture meters (Lindegaard and Morsing 2006). The aim is that the test should form the basis of evaluation of the maintenance requirements and the prediction of service life of the surface treatment and the wood/construction. At the moment 60 test racks...

  9. BROAD PHONEME CLASSIFICATION USING SIGNAL BASED FEATURES

    Directory of Open Access Journals (Sweden)

    Deekshitha G

    2014-12-01

    Full Text Available Speech is the most efficient and popular means of human communication Speech is produced as a sequence of phonemes. Phoneme recognition is the first step performed by automatic speech recognition system. The state-of-the-art recognizers use mel-frequency cepstral coefficients (MFCC features derived through short time analysis, for which the recognition accuracy is limited. Instead of this, here broad phoneme classification is achieved using features derived directly from the speech at the signal level itself. Broad phoneme classes include vowels, nasals, fricatives, stops, approximants and silence. The features identified useful for broad phoneme classification are voiced/unvoiced decision, zero crossing rate (ZCR, short time energy, most dominant frequency, energy in most dominant frequency, spectral flatness measure and first three formants. Features derived from short time frames of training speech are used to train a multilayer feedforward neural network based classifier with manually marked class label as output and classification accuracy is then tested. Later this broad phoneme classifier is used for broad syllable structure prediction which is useful for applications such as automatic speech recognition and automatic language identification.

  10. DNA Damage among Wood Workers Assessed with the Comet Assay

    Science.gov (United States)

    Bruschweiler, Evin Danisman; Wild, Pascal; Huynh, Cong Khanh; Savova-Bianchi, Dessislava; Danuser, Brigitta; Hopf, Nancy B.

    2016-01-01

    Exposure to wood dust, a human carcinogen, is common in wood-related industries, and millions of workers are occupationally exposed to wood dust worldwide. The comet assay is a rapid, simple, and sensitive method for determining DNA damage. The objective of this study was to investigate the DNA damage associated with occupational exposure to wood dust using the comet assay (peripheral blood samples) among nonsmoking wood workers (n = 31, furniture and construction workers) and controls (n = 19). DNA damage was greater in the group exposed to composite wood products compared to the group exposed to natural woods and controls (P < 0.001). No difference in DNA damage was observed between workers exposed to natural woods and controls (P = 0.13). Duration of exposure and current dust concentrations had no effect on DNA damage. In future studies, workers’ exposures should include cumulative dust concentrations and exposures originating from the binders used in composite wood products. PMID:27398027

  11. Giant Broad Line Regions in Dwarf Seyferts

    CERN Document Server

    Devereux, Nick

    2015-01-01

    High angular resolution spectroscopy obtained with the Hubble Space Telescope (HST) has revealed a remarkable population of galaxies hosting dwarf Seyfert nuclei with an unusually large broad-line region (BLR). These objects are remarkable for two reasons. Firstly, the size of the BLR can, in some cases, rival those seen in the most luminous quasars. Secondly, the size of the BLR is not correlated with the central continuum luminosity, an observation that distinguishes them from their reverberating counterparts. Collectively, these early results suggest that non-reverberating dwarf Seyferts are a heterogeneous group and not simply scaled versions of each other. Careful inspection reveals broad H Balmer emission lines with single peaks, double peaks, and a combination of the two, suggesting that the broad emission lines are produced in kinematically distinct regions centered on the black hole (BH). Because the gravitational field strength is already known for these objects, by virtue of knowing their BH mass, ...

  12. Silicon micromachined broad band light source

    Science.gov (United States)

    George, Thomas (Inventor); Jones, Eric (Inventor); Tuma, Margaret L. (Inventor); Eastwood, Michael (Inventor); Hansler, Richard (Inventor)

    2004-01-01

    A micro electromechanical system (MEMS) broad band incandescent light source includes three layers: a top transmission window layer; a middle filament mount layer; and a bottom reflector layer. A tungsten filament with a spiral geometry is positioned over a hole in the middle layer. A portion of the broad band light from the heated filament is reflective off the bottom layer. Light from the filament and the reflected light of the filament are transmitted through the transmission window. The light source may operate at temperatures of 2500 K or above. The light source may be incorporated into an on board calibrator (OBC) for a spectrometer.

  13. General Regularities of Wood Surface Roughness

    Directory of Open Access Journals (Sweden)

    MAGOSS, Endre

    2008-01-01

    Full Text Available The surface roughness of wood products is depending on many factors related both towood properties and wood working operational parameters. Probably this is the reason why there areno generally valid correlation determining surface roughness parameters as a function of influencingfactors. In particular, the account of wood structure in the surface roughness interpretation proved tobe difficult.In the last years an important progress was made in recognizing the role of the anatomicalstructure of wood species in the attainable surface roughness. The introduction of a structure numbermade it possible to express and characterize the different wood species numerically.The aim of these studies was the separation of roughness components due to the anatomicalstructure and the woodworking operation. Using a special finishing technique, the roughnesscomponent due to woodworking operations was not significant and could be separated. The samespecimens were also subjected to different woodworking operations using cutting velocities between10 and 50 m/s. The processing of experimental data resulted in a chart showing the minimumroughness component due to different woodworking operations. Special experimental investigationwas conducted to clear the influence of edge dullness on the surface roughness, especially on itsAbbott-parameters. The measurements showed that the Rk-parameter is a good indicator to predictedge dullness.

  14. MICROBIAL LOAD AND MULTIPLE DRUG RESISTANCE OF PATHOGENIC BACTERIA ISOLATED FROM FEACES AND BODY SURFACES OF COCKROACHES IN AN URBAN AREA OF SOUTHWESTERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Monsuru Adebayo Adeleke

    2012-06-01

    Full Text Available This study investigates the microbial load and antibiotic susceptibility pattern of pathogenic bacteria isolated from the faeces and body surfaces of cockroaches in Osogbo, Southwestern Nigeria. The cockroaches collected from residential areas and hospital vicinities were screened for microbial load and antibiotic susceptibility pattern using standard protocols. A total of twenty- three microorganisms namely Klebsiella aerogenes, Bacillius cereus, Proteus spp, Staphyloccocus aureus, S. saprophyticus, Enteroccocus faecalis, Staphylococus epididermis, E. coli, Listeria monoctogene, Proteus mirabilis, Citrobacter species, Pseudomonas aeruginosa, Psuedomonas species, Seretia mensence, Candida albicans, Candida spp., Aspergilius spp., A. flavus, A. fumigates, Mucor species and Penicilium species were isolated. The microbial load of the microorganisms was significantly higher in the isolates from hospital as compared with the residential area (p<0.05 with the exception of Canidida species, Mucor and Penicillium which had higher or equal microbial load at the residential areas. All the pathogenic bacteria isolated had multiple resistance to antibiotics most importantly, Ampicillin, Augumentin, Amoxicillin and Septrin (30μg. Efforts geared towards controlling the insects will be indispensable in curbing the wide spread of multi-drug resistant pathogens in the study area.

  15. Isolation and Identification of Two Novel Attractant Compounds from Chinese Cockroach (Eupolyphaga sinensis Walker by Combination of HSCCC, NMR and CD Techniques

    Directory of Open Access Journals (Sweden)

    Bin Wu

    2013-09-01

    Full Text Available High-speed counter-current chromatography (HSCCC with a two-phase solvent system composed of n-hextane-ethyl acetate-methanol-water (1.5:1:1.5:1, v/v/v/v was applied to the isolation and purification of attractants from Chinese cockroach, Eupolyphaga sinensis Walker. Two new attractants with attractant activity towards the male insects were obtained from the extract sample in a one-step separation. Their purities were determined by HPLC. Subsequent MS, NMR and CD analyses have led to the characterization of (R-3-ethyl-6,8-dihydroxy-7-methyl-3,4-dihydroisochromen-1-one (1 and (R-6,8-dihydroxy-3,7-dimethyl-3,4-dihydroisochromen-1-one (2, two novel isocumarin type attractants. Based on these results, it is concluded that HSCCC is a viable separation method option for purifying insect attractants, while effectively maintaining the attracting activity of the isolates. This is the first attempt to apply counter-current chromatography technique to separate attractants from Chinese cockroach.

  16. A sodium channel mutation identified in Aedes aegypti selectively reduces cockroach sodium channel sensitivity to type I, but not type II pyrethroids.

    Science.gov (United States)

    Hu, Zhaonong; Du, Yuzhe; Nomura, Yoshiko; Dong, Ke

    2011-01-01

    Voltage-gated sodium channels are the primary target of pyrethroid insecticides. Numerous point mutations in sodium channel genes have been identified in pyrethroid-resistant insect species, and many have been confirmed to reduce or abolish sensitivity of channels expressed in Xenopus oocytes to pyrethroids. Recently, several novel mutations were reported in sodium channel genes of pyrethroid-resistant Aedes mosquito populations. One of the mutations is a phenylalanine (F) to cysteine (C) change in segment 6 of domain III (IIIS6) of the Aedes mosquito sodium channel. Curiously, a previous study showed that alanine substitution of this F did not alter the action of deltamethrin, a type II pyrethroid, on a cockroach sodium channel. In this study, we changed this F to C in a pyrethroid-sensitive cockroach sodium channel and examined mutant channel sensitivity to permethrin as well as five other type I or type II pyrethroids in Xenopus oocytes. Interestingly, the F to C mutation drastically reduced channel sensitivity to three type I pyrethroids, permethrin, NRDC 157 (a deltamethrin analogue lacking the α-cyano group) and bioresemthrin, but not to three type II pyrethroids, cypermethrin, deltamethrin and cyhalothrin. These results confirm the involvement of the F to C mutation in permethrin resistance, and raise the possibility that rotation of type I and type II pyrethroids might be considered in the control of insect pest populations where this particular mutation is present.

  17. The effects of huwentoxin-I on the voltage-gated sodium channels of rat hippocampal and cockroach dorsal unpaired median neurons.

    Science.gov (United States)

    Wang, Meichi; Rong, Mingqiang; Xiao, Yucheng; Liang, Songping

    2012-03-01

    Huwentoxin-I (HWTX-I) is a 33-residue peptide isolated from the venom of Ornithoctonus huwena and could inhibit TTX-sensitive voltage-gated sodium channels and N-type calcium channels in mammalian dorsal root ganglion (DRG) neurons. However, the effects of HWTX-I on mammalian central neuronal and insect sodium channel subtypes remain unknown. In this study, we found that HWTX-I potently inhibited sodium channels in rat hippocampal and cockroach dorsal unpaired median (DUM) neurons with the IC(50) values of 66.1±5.2 and 4.80±0.58nM, respectively. Taken together with our previous work on DRG neurons (IC(50)≈55nM), the order of sodium channel sensitivity to HWTX-I inhibition was insect central DUM≫mammalian peripheral>mammalian central neurons. HWTX-I exhibited no effect on the steady-state activation and inactivation of sodium channels in rat hippocampal and cockroach DUM neurons. PMID:22094230

  18. Structure of a heterogeneous, glycosylated, lipid-bound, in vivo-grown protein crystal at atomic resolution from the viviparous cockroach Diploptera punctata.

    Science.gov (United States)

    Banerjee, Sanchari; Coussens, Nathan P; Gallat, François-Xavier; Sathyanarayanan, Nitish; Srikanth, Jandhyam; Yagi, Koichiro J; Gray, James S S; Tobe, Stephen S; Stay, Barbara; Chavas, Leonard M G; Ramaswamy, Subramanian

    2016-07-01

    Macromolecular crystals for X-ray diffraction studies are typically grown in vitro from pure and homogeneous samples; however, there are examples of protein crystals that have been identified in vivo. Recent developments in micro-crystallography techniques and the advent of X-ray free-electron lasers have allowed the determination of several protein structures from crystals grown in cellulo. Here, an atomic resolution (1.2 Å) crystal structure is reported of heterogeneous milk proteins grown inside a living organism in their functional niche. These in vivo-grown crystals were isolated from the midgut of an embryo within the only known viviparous cockroach, Diploptera punctata. The milk proteins crystallized in space group P1, and a structure was determined by anomalous dispersion from the native S atoms. The data revealed glycosylated proteins that adopt a lipocalin fold, bind lipids and organize to form a tightly packed crystalline lattice. A single crystal is estimated to contain more than three times the energy of an equivalent mass of dairy milk. This unique storage form of nourishment for developing embryos allows access to a constant supply of complete nutrients. Notably, the crystalline cockroach-milk proteins are highly heterogeneous with respect to amino-acid sequence, glycosylation and bound fatty-acid composition. These data present a unique example of protein heterogeneity within a single in vivo-grown crystal of a natural protein in its native environment at atomic resolution. PMID:27437115

  19. The GREGOR Broad-Band Imager

    Science.gov (United States)

    von der Lühe, O.; Volkmer, R.; Kentischer, T. J.; Geißler, R.

    2012-11-01

    The design and characteristics of the Broad-Band Imager (BBI) of GREGOR are described. BBI covers the visible spectral range with two cameras simultaneously for a large field and with critical sampling at 390 nm, and it includes a mode for observing the pupil in a Foucault configuration. Samples of first-light observations are shown.

  20. Broad resonances and beta-decay

    DEFF Research Database (Denmark)

    Riisager, K.; Fynbo, H. O. U.; Hyldegaard, S.;

    2015-01-01

    Beta-decay into broad resonances gives a distorted lineshape in the observed energy spectrum. Part of the distortion arises from the phase space factor, but we show that the beta-decay matrix element may also contribute. Based on a schematic model for p-wave continuum neutron states it is argued...

  1. Directed abstraction: Encouraging broad, personal generalizations following a success experience.

    Science.gov (United States)

    Zunick, Peter V; Fazio, Russell H; Vasey, Michael W

    2015-07-01

    People with negative self-views may fail to generalize appropriately from success experiences (e.g., Wood, Heimpel, Newby-Clark, & Ross, 2005). We drew on theories regarding self-views (Swann, Griffin, Predmore, & Gaines, 1987) and abstraction (Semin & Fiedler, 1991), as well as past linguistic framing work (e.g., Marigold, Holmes, & Ross, 2007, 2010; Salancik, 1974), to create a new technique to encourage people with negative self-views to generalize broadly from a success experience to the self-concept. We call this technique directed abstraction. In Experiment 1, participants with negative self-views who completed a directed abstraction writing task following success feedback regarding a novel laboratory task generalized more from that success, reporting higher ability levels and greater expectations of future success in the relevant domain. In Experiment 2, directed abstraction produced similar results (including more positive self-related affect, e.g., pride) after participants recalled a past public speaking success. In Experiment 3, participants high in fear of public speaking gave two speeches in a context designed to be challenging yet also to elicit successful performances. Directed abstraction helped these participants generalize from their success to beliefs about their abilities, expectations about the future, and confidence as a speaker. In Experiment 4, directed abstraction following success on a verbal task increased persistence in the face of failure on a subsequent verbal task. We discuss implications for understanding how and when people generalize from a success, compare directed abstraction to existing interventions, and suggest practical applications for this influence technique. PMID:25984786

  2. Bamboo and Wood in Musical Instruments

    Science.gov (United States)

    Wegst, Ulrike G. K.

    2008-08-01

    Over centuries and millennia, our ancestors worldwide found the most appropriate materials for increasingly complex acoustical applications. In the temperate climate of Europe, where the instruments of the Western symphony orchestra were developed and perfected, instrument makers still primarily take advantage of the unique property combination and the aesthetic appeal of wood. In all other continents, one material dominates and is frequently chosen for the manufacture of wind, string, and percussion instruments: the grass bamboo. Here, we review from a materials science perspective bamboo's and wood's unique and highly optimized structure and properties. Using material property charts plotting acoustic properties such as the speed of sound, the characteristic impedance, the sound radiation coefficient, and the loss coefficient against one another, we analyze and explain why bamboo and specific wood species are ideally suited for the manufacture of xylophone bars and chimes, flutes and organs, violins and zithers, violin bows, and even strings.

  3. Brazilian Market Structure of Wood Briquettes

    Energy Technology Data Exchange (ETDEWEB)

    Gentil, L.V. (Univ. of Brasilia, Forest Dept, Brasilia (Brazil)). E-mail: gentil22@unb.br; Vieira, A.M.C. (Univ. of Brasilia, Dept. of Statistics, Brasilia (Brazil))

    2008-10-15

    The bioenergy market and wood briquette market grew starting from the oil crisis in 1973, when it began the fossil fuels replacement. Lignocellulosic wastes have larger specific calorific power and quality than agricultural, peat and sugar cane bagasse. Knowledge of the briquette market with larger efficient scientific tools and smaller costs, is as important in this work as using improved SWOT Analysis of research market with a Multiple Mode and a Correspondence Analysis Mode. The results of this research show that the supply strengths are the quality and amount of energy from wood briquette. The supply weaknesses are expensive freight and briquette vulnerability to the moisture. The demand opportunities are the many uses of wood briquette in several market segments. The demand threats are the absence of a good distribution and expensive freight for the delivery

  4. Wood flow problems in the Swedish forestry

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Dick [Forestry Research Inst. of Sweden, Uppsala (Sweden); Roennqvist, M. [Linkoeping Univ. (Sweden). Dept. of Mathematics

    1998-12-31

    In this paper we give an overview of the wood-flow in Sweden including a description of organization and planning. Based on that, we will describe a number of applications or problem areas in the wood-flow chain that are currently considered by the Swedish forest companies to be important and potential in order to improve overall operations. We have focused on applications which are short term planning or operative planning. We do not give any final results as much of the development is currently ongoing or is still in a planning phase. Instead we describe what kind of models and decision support systems that could be applied in order to improve co-operation within and integration of the wood-flow chain 13 refs, 20 figs, 1 tab

  5. Research advance in wood composites in China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Wood composites can generally be classified in three parts: laminated composites, mixed composites and penetrated composites. Every part has its own characteristic and can be further divided. This paper introduces the history and the state of development of wood composites in China. The research about glue-laminated timber is rare and the industry hardly comes to being. A great of achievements have been obtained in mixed composites and it is well industrialized. Many studies on scrimber have been done and the Chinese researchers are looking for a feasible way to develop the scrimber industry in China. Chinese researchers also spent so much energy in studying wood plastic composites (WPC), but it has not been industrialized due to the high cost.

  6. Properties of Wood/Montmorillonite Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    LV Wenhua; ZHAO Guangjie

    2006-01-01

    With montmorillonite (MMT) organically modified as organophilic-MMT (OMMT) and water-soluble phenol formaldehyde resin (PF) as intermediate, the nanocomposites of Chinese fir (Cunninghamia lanceolata) wood and MMT, i.e. WMNC, were prepared via nano intercalation compounding, some properties of WMNC were analyzed. Results show that, compared with Chinese fir wood and its PF-impreg, WMNC has lower humidity and water absorption, better dimension stability, higher longitudinal compressive strength, abrasive resistance, fire-resistance, and water-leaching resistance with a very low mass ratio about 3% of MMT. The nano intercalation compounding of wood and exfoliated MMT nanolamellae is very promising. More studies should be carried out to fully reveal the nanosize effects and the special properties of WMNC.

  7. How to quantify conduits in wood?

    Science.gov (United States)

    Scholz, Alexander; Klepsch, Matthias; Karimi, Zohreh; Jansen, Steven

    2013-01-01

    Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.

  8. How to quantify conduits in wood?

    Directory of Open Access Journals (Sweden)

    Alexander eScholz

    2013-03-01

    Full Text Available Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.

  9. Thermal Diffusion in Masson Pine Wood

    Institute of Scientific and Technical Information of China (English)

    Li Xian-jun; Zhang Bi-guang; Li Wen-jun

    2005-01-01

    In order to analyze the effects of the temperature gradient on moisture movement during the highly intensive microwave-vacuum drying, thermal diffusion of Masson pine wood was studied. Internal distribution of temperature and moisture in Masson pine samples sealed by epoxy resin and aluminum foil was measured, the magnitude of thermal diffusion was calculated and the influencing factors of thermal diffusion were discussed. Results showed that with the transfer of moisture toward the low temperature in wood, opposite temperature and moisture gradient occurred. The initial moisture content (MC), temperature and time are important factors affecting this process; the thermal diffusion is in proportion to wood temperature, its initial moisture and time. The temperature and distance from hot surface is strongly linearly correlated, and the relationship between MCs at different locations and distance from the hot end surface changes from logarithmically form to exponentially form with the increase in experimental time.

  10. Genetic improvement of trees for wood production, with particular refeference to wood traits

    Directory of Open Access Journals (Sweden)

    Nocetti M

    2008-03-01

    Full Text Available The use of selected propagation material from tree improvement programs is expected to lead to a more homogenous product, generally appreciated by industry. So far, breeding strategy have been mainly targeted to maximize acclimation/adaptation to specific environment conditions, tree growth and disease resistance, but it is not obvious that such strategy might lead to improvement of wood characteristics at the same time. Therefore, it seems important to introduce wood traits improvement as specific target of the selection process in tree breeding programs, and/or to assess heritability of wood technological properties of trees previously selected based on different criteria. Investigations reported so far have revealed that several wood traits are under a medium to high genetic control. The main goal of this work is to discuss the suitability of wood traits improvement as main target of specific breeding programs, with particular attention to wood technological characteristics to be considered in the tree selection process. Finally, we focused on noble hardwoods, that have been the target species for many improvement programs developed in Italy, and particularly on wild cherry, where studies on the genetic control of wood traits are rare.

  11. Characteristics of heat-treated Turkish pine and fir wood after ThermoWood processing.

    Science.gov (United States)

    Kol, Hamiyet Sahin

    2010-11-01

    The Finnish wood heat treatment technology ThermoWood, was recently introduced to Turkey. Data about the mechanical and physical properties of Turkish wood species are important for industry and academia. In this study two industrially important Turkish wood species, pine (Pinus nigraArnold.) and fir (Abies bornmülleriana Matf.) were heat-treated using the ThermoWood process. Pine and fir samples were thermally modified for 2 hr at 212 and 190 degrees C, respectively. The modulus of rupture (MOR), modulus of elasticity in bending (MOE), impact bending strength (IBS), and compression strength (CS), in addition to swelling (Sw) and shrinkage (Sh) of thermally-modified wood were examined. The results indicate that the heat treatment method clearly decreased the MOR, MOE and lBS of pine and fir. However, a small increase was observed for CS values of heat treated wood species. The most affected mechanical properties were MOR and lBS for both pine and fir. The reduction in MOE was smaller than that in MOR and lBS. Volumetric shrinkage and swelling of these species were also improved by approximately half. In Addition, the changes in the mechanical and physical properties studied in pine were larger than that of fir.

  12. Temperature Evolution in Poplar (Populus nigra Tension Wood and Normal Wood during a Conventional Drying Process

    Directory of Open Access Journals (Sweden)

    Asghar TARMIAN

    2011-08-01

    Full Text Available In this paper, temperature evolution through tension wood and normal wood in poplar (Populus nigra under a convective drying condition was investigated. Flat-sawn boards with green dimensions 80�40�25 mm were dried at constant dry-bulb temperature of 60�C and relative humidity (RH of 50% to a final moisture content of about 8%. They were coated on four surfaces using aluminum foil bonded with polyurethane (PU glue to confine moisture movement along the board thickness. The measurement of board temperature was carried out at 2.5, 5, 7.5, 10 and 12.5 mm along the board thickness every 20 minutes by means of 1 mm-thermocouples. The pattern of temperature profile was observed to be almost similar for both tension wood and normal wood. However, a slightly steeper temperature gradient occurred in the normal wood compared to the tension wood. In both types of woods, the surface temperature rose progressively from the initial value to the dry-bulb temperature but the core temperature remained at an almost constant value as the wet-bulb temperature even at the end of drying.

  13. Lung function: occupational exposure to wood dust

    Directory of Open Access Journals (Sweden)

    Baran S

    2009-12-01

    Full Text Available Abstract Objectives Occupational exposure to wood dust has been shown to cause several respiratory disorders, such as allergic rhinitis, chronic bronchitis, asthma, sino-nasal adenocarcinoma, and impairment of lung function. The aim of the study was to estimate lung function (in the woodworking industry among workers employed by wood processing, who run the risk of being expose to wood dust. Methods The study concerns a group of 70 workers aged 24-55. All the workers underwent general and laryngological examination. A group of 20 workers, working at the positions where dustiness exceeded TLV (threshold limit value took X-ray of the chest and spirometry. The following parameters were measured: VC, IC, ERV, TV, BF, FEV1, FVC, PEF, MEF25-75, FEV1%FVC, FEV1%VC. The data are presented as means ± SD and the authors applied references values according to ERS guidelines. Results The results show that there was no decline in FEV1 (3.7 ± 0.7 and FVC (4.5 ± 0.8. Normal lung function was defined as FEV1/VC ratio ≥0.7. None of the tested workers had obstructive pattern in spirometry. The mean FEV1%VC was 77.1 ± 10.2. These results suggest that wood dust exposure might not lead to significant pulmonary damage. Conclusions These data do not corroborate that wood dust plays significant role in lung function impairment. Future studies of respiratory health among workers exposed to wood dust are needed.

  14. Chemical and physical characterization of emissions from birch wood combustion in a wood stove

    Science.gov (United States)

    Hedberg, Emma; Kristensson, Adam; Ohlsson, Michael; Johansson, Christer; Johansson, Per-Åke; Swietlicki, Erik; Vesely, Vaclav; Wideqvist, Ulla; Westerholm, Roger

    The purpose of this study was to characterize the emissions of a large number of chemical compounds emitted from birch wood combustion in a wood stove. Birch wood is widely used as fuel in Swedish household appliances. The fuel load was held constant during six experiments. Particles dust, range 30-330 for the former and 0.8±0.15 for the latter. The source profile of common elements emitted from wood burning differed from that found on particles at a street-level site or in long-distance transported particles. The ratio toluene/benzene in this study was found to be in the range 0.2-0.7, which is much lower than the ratio 3.6±0.5 in traffic exhaust emissions. Formaldehyde and acetone were the most abundant compounds among the volatile ketones and aldehydes. The emission factor varied between 180-710 mg/kg wood for formaldehyde and 5-1300 mg/kg wood for acetone. Of the organic acids analyzed (3,4,5)-trimethoxy benzoic acid was the most abundant compound. Of the PAHs reported, fluorene, phenanthrene, anthracene, fluoranthene and pyrene contribute to more than 70% of the mass of PAH. Of the elements analyzed, K and Si were the most abundant elements, having emission factors of 27 and 9 mg/kg wood, respectively. Although fluoranthene has a toxic equivalence factor of 5% of benzo(a)pyrene (B(a)P), it can be seen that the toxic potency of fluoranthene in wood burning emissions is of the same size as B(a)P. This indicates that the relative carcinogenic potency contribution of fluoranthene in wood smoke would be about 40% of B(a)P.

  15. Strength of glue line for reforestation wood

    Directory of Open Access Journals (Sweden)

    Pedro Gutemberg de Alcântara Segundinho

    2015-05-01

    Full Text Available This paper aims to evaluate the shear strength of glued laminated timber (glulam made of three wood species: Tectona grandis, Pinus oocarpa and Eucalyptus sp.. The bonds were made with lamellae with no chemical treatment, using two-component adhesive based on melamine-urea-formaldehyde (MUF. Glue line shear tests were made for wood in local moisture content and high humidity, as well as delamination tests. The results presented in the glue line shear strength tests in dry condition and delamination for the three species indicate better performance of Pinus oocarpa. It was concluded that this species there is potential to produce MLC utilizing the MUF adhesive.

  16. Application of Nanoindentation Technique in Wood Science

    Institute of Scientific and Technical Information of China (English)

    WU Yan; ZHOU Dingguo; WANG Siqun; ZHANG Yang

    2006-01-01

    Nanoindentation technique is a technique that determines the mechanical properties of a material in sub-micron scale. The technique involves penetrating a sample material using an indenter, while the penetration depth and load are recorded so that stiffness and hardness of the indented location can be subsequently calculated. The micron spatial resolution in nanoindentaion tests renders the technique very useful in the investigation of the wood cell-wall level and polymer interphase. This review mainly discussed the principle of nanoindentation and its current applications in wood science field.

  17. International Trade of Wood Pellets (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-05-01

    The production of wood pellets has increased dramatically in recent years due in large part to aggressive emissions policy in the European Union; the main markets that currently supply the European market are North America and Russia. However, current market circumstances and trade dynamics could change depending on the development of emerging markets, foreign exchange rates, and the evolution of carbon policies. This fact sheet outlines the existing and potential participants in the wood pellets market, along with historical data on production, trade, and prices.

  18. Wood-Plastic Composites in the Wood-Carving Industry in the Far East

    International Nuclear Information System (INIS)

    Only the Republic of China (Taiwan) and the Philippines have shown interest in the use of WPC for wood-carving purposes. Japan and Korea, however, are interested in the possibilities of WPC for the manufacture of such specialized items as shuttles (used in weaving), musical instruments, furniture and sporting goods (such as tennis rackets, baseball bats, skis, etc.). Viet Nam, Korea and Thailand have at present little or no experience with WPC, but they intend to start work in this area. Generally speaking, these countries possess abundant hard and soft woods and are interested in using soft woods for WPC. The main problem concerns the high cost and the availability of monomers

  19. Community turnover of wood-inhabiting fungi across hierarchical spatial scales.

    Directory of Open Access Journals (Sweden)

    Nerea Abrego

    Full Text Available For efficient use of conservation resources it is important to determine how species diversity changes across spatial scales. In many poorly known species groups little is known about at which spatial scales the conservation efforts should be focused. Here we examined how the community turnover of wood-inhabiting fungi is realised at three hierarchical levels, and how much of community variation is explained by variation in resource composition and spatial proximity. The hierarchical study design consisted of management type (fixed factor, forest site (random factor, nested within management type and study plots (randomly placed plots within each study site. To examine how species richness varied across the three hierarchical scales, randomized species accumulation curves and additive partitioning of species richness were applied. To analyse variation in wood-inhabiting species and dead wood composition at each scale, linear and Permanova modelling approaches were used. Wood-inhabiting fungal communities were dominated by rare and infrequent species. The similarity of fungal communities was higher within sites and within management categories than among sites or between the two management categories, and it decreased with increasing distance among the sampling plots and with decreasing similarity of dead wood resources. However, only a small part of community variation could be explained by these factors. The species present in managed forests were in a large extent a subset of those species present in natural forests. Our results suggest that in particular the protection of rare species requires a large total area. As managed forests have only little additional value complementing the diversity of natural forests, the conservation of natural forests is the key to ecologically effective conservation. As the dissimilarity of fungal communities increases with distance, the conserved natural forest sites should be broadly distributed in space, yet

  20. Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia.

    Science.gov (United States)

    Distel, Daniel L; Amin, Mehwish; Burgoyne, Adam; Linton, Eric; Mamangkey, Gustaf; Morrill, Wendy; Nove, John; Wood, Nicole; Yang, Joyce

    2011-11-01

    The ability to consume wood as food (xylotrophy) is unusual among animals. In terrestrial environments, termites and other xylotrophic insects are the principle wood consumers while in marine environments wood-boring bivalves fulfill this role. However, the evolutionary origin of wood feeding in bivalves has remained largely unexplored. Here we provide data indicating that xylotrophy has arisen just once in Bivalvia in a single wood-feeding bivalve lineage that subsequently diversified into distinct shallow- and deep-water branches, both of which have been broadly successful in colonizing the world's oceans. These data also suggest that the appearance of this remarkable life habit was approximately coincident with the acquisition of bacterial endosymbionts. Here we generate a robust phylogeny for xylotrophic bivalves and related species based on sequences of small and large subunit nuclear rRNA genes. We then trace the distribution among the modern taxa of morphological characters and character states associated with xylotrophy and xylotrepesis (wood-boring) and use a parsimony-based method to infer their ancestral states. Based on these ancestral state reconstructions we propose a set of plausible hypotheses describing the evolution of symbiotic xylotrophy in Bivalvia. Within this context, we reinterpret one of the most remarkable progressions in bivalve evolution, the transformation of the "typical" myoid body plan to create a unique lineage of worm-like, tube-forming, wood-feeding clams. The well-supported phylogeny presented here is inconsistent with most taxonomic treatments for xylotrophic bivalves, indicating that the bivalve family Pholadidae and the subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic, and that the principle traits used for their taxonomic diagnosis are phylogenetically misleading.

  1. USE OF CANDEIA’S (Eremanthus erythropappus WASTE WOOD

    Directory of Open Access Journals (Sweden)

    Rosimeire Cavalcante dos Santos

    2008-09-01

    Full Text Available The candeia (Eremanthus erythropappus is a native forest species with multiple uses and specially utilized as essential oils source. The use of the candeia´s waste wood after oil extraction for particle panels production becomes a viable alternative, avoiding environmental problems and increasing the availability of these products in the consuming market. This work verified the viability of producing wood-cement panels using waste wood generated after the extraction of candeia’s oil, in association with pinus and eucalipto woods. The experiment was installed according to a completely randomized design with three repetitions. The treatments were arranged according to a factorial 2 x 3 scheme (two wooden species and three replacement percentages of the woods by candeia’s waste. The results of the physical and mechanical property tests showed high potentiality of candeia waste wood, after oil extraction, in association with pinus and eucalipto wood for manufacturing wood-cement panels.

  2. Investigation of modified cottonseed protein adhesives for wood composites

    Science.gov (United States)

    Several modified cottonseed protein isolates were studied and compared to corresponding soy protein isolates for their adhesive properties when bonded to wood composites. Modifications included treatments with alkali, guanidine hydrochloride, sodium dodecyl sulfate (SDS), and urea. Wood composites...

  3. Biodeterioration of wood in estuarine ecosystem of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Yennawar, P.L; Thakur, N.L; Venkat, K.; Anil, A.C.; Wagh, A.B.

    community was dominated by Martesia striata in pre-monsoon and post-monsoon seasons and by L. pedicellatus in monsoon. The macrofouling and wood boring communities which mainly contributes in biodeterioration of wood is discussed in this paper...

  4. Wood anatomy of Argyroxiphium (Asteraceae): adaptive radiation and ecological correlations

    International Nuclear Information System (INIS)

    Wood anatomy shows close correlation with ecology: A. kauense, A. sandwicense (stem), and A. virescens, which occur in dry localities, show xeromorphic wood patterns. The most mesomorphic woods are those of the bog species A. grayanum and root wood of A. sandwicense. The wood of A. caliginis is xeromorphic, despite the bog habitat of the species, a fact explainable if A. caliginis is a recent entrant into the bog habitat Libriform wall thickness appears correlated with habit. Quantitative features of stem woods of Argyroxiphium are comparable to woods ranging from desert to moist montane forest areas in California. The similarities to woods from each Californian habitat are correlative to the relative moisture availability of the respective Hawaiian habitats of the Argyroxiphium species. (author)

  5. PRESERVATIVE LEACHING FROM WEATHERED CCA-TREATED WOOD

    Science.gov (United States)

    Disposal of discarded CCA-treated wood in landfills raises concerns with respect to leaching of preservative compounds. When unweathered CCA-treated wood is leached using the toxicity characteristic leaching procedure (TCLP), arsenic concentrations exceed the toxicity characteris...

  6. Profitability of wood harvesting enterprises

    Energy Technology Data Exchange (ETDEWEB)

    Penttinen, M. email: markku.penttinen@metla.fi; Mikkola, J. email: jarmo.mikkola@metla.fi; Rummukainen, A. email: arto.rummukainen@metla.fi

    2009-07-01

    The forest machine business is about 50 years old. The rapid technical development of machinery increased productivity up to the end of last century. In 2007, the total value of round and energy wood harvesting and silvicultural work operated by forest machine enterprises exceeded 570 mill. euro. According to the materials of the Vehicle Administration Finland and Statistics Finland there are about 1 600 active harvesting enterprises in the personal and business taxation system. Beside this, there are according to the Ministry of Agriculture and Forestry about 1 300 farmers who do harvesting as side business. About 1 000 enterprises working in June 2007 were studied with their retrospective economic analyses from 2001. The data includes all enterprises that had supplied closing of the accounts data. One-machine entrepreneurs represent more than a third of the number of enterprises, but only 13 percent of the turnover. Enterprises with seven or more machines represent less than ten percent of the number, but over twenty percent of the turnover. Enterprises are largest in eastern and northern Finland, where the average number of machines per enterprise exceeds three. Small enterprises are mostly singleowner business enterprises with a median turnover of 125 000 euros per annum. Partnerships and limited enterprises have double the median turnover of single-owner businesss. Limited companies turn over a median of 450 000 euro/y, representing 67 percent of total turnover. Median net profit varied between 6 and 10 percent of turnover in 2001-2007, but only between 2 and 4 percent where the wage adjustment is deducted from the profit. The wage adjustment is estimated as if the owners of single-owner businesses earn an operator's salary. Profit was highest in 2002 and lowest 2006. In the smallest enterprise class with a turnover of less than 75 000 euro/y, profit was lowest and negative in 2006 and 2007. The variation in profits between enterprises was also biggest in

  7. Oral tolerance inhibits pulmonary eosinophilia in a cockroach allergen induced model of asthma: a randomized laboratory study

    Directory of Open Access Journals (Sweden)

    Natarajan Sudha

    2010-11-01

    Full Text Available Abstract Background Antigen desensitization through oral tolerance is becoming an increasingly attractive treatment option for allergic diseases. However, the mechanism(s by which tolerization is achieved remain poorly defined. In this study we endeavored to induce oral tolerance to cockroach allergen (CRA: a complex mixture of insect components in order to ameliorate asthma-like, allergic pulmonary inflammation. Methods We compared the pulmonary inflammation of mice which had received four CRA feedings prior to intratracheal allergen sensitization and challenge to mice fed PBS on the same time course. Respiratory parameters were assessed by whole body unrestrained plethysmography and mechanical ventilation with forced oscillation. Bronchoalveolar lavage fluid (BAL and lung homogenate (LH were assessed for cytokines and chemokines by ELISA. BAL inflammatory cells were also collected and examined by light microscopy. Results CRA feeding prior to allergen sensitization and challenge led to a significant improvement in respiratory health. Airways hyperreactivity measured indirectly via enhanced pause (Penh was meaningfully reduced in the CRA-fed mice compared to the PBS fed mice (2.3 ± 0.4 vs 3.9 ± 0.6; p = 0.03. Directly measured airways resistance confirmed this trend when comparing the CRA-fed to the PBS-fed animals (2.97 ± 0.98 vs 4.95 ± 1.41. This effect was not due to reduced traditional inflammatory cell chemotactic factors, Th2 or other cytokines and chemokines. The mechanism of improved respiratory health in the tolerized mice was due to significantly reduced eosinophil numbers in the bronchoalveolar lavage fluid (43300 ± 11445 vs 158786 ± 38908; p = 0.007 and eosinophil specific peroxidase activity in the lung homogenate (0.59 ± 0.13 vs 1.19 ± 0.19; p = 0.017. The decreased eosinophilia was likely the result of increased IL-10 in the lung homogenate of the tolerized mice (6320 ± 354 ng/mL vs 5190 ± 404 ng/mL, p = 0

  8. Are eavesdroppers multimodal?Sensory exploitation of floral signals by a non-native cockroach Blatta orientalis

    Institute of Scientific and Technical Information of China (English)

    Rodrigo C.VERGARA; Alejandra TORRES-ARANEDA; Diego A.VILLAGRA; Robert A.RAGUSO; Mary T.K.ARROYO; Cristian A.BILLAGRA

    2011-01-01

    The study of multi-modal communication has only recently been extended to innate and learned interactions between flowers and their animal visitors,and usually only to pollinators.Here we studied the relevance of floral scent and visual display of a night blooming,putatively hawkmoth-poilinated plant Oenothera acaulis(Onagraceae)in the attraction of non-native cockroaches Blatta orientalis(Blattodea:Blattldae),which function as facultative floral lajrcenists in coastal habitats of central Chile.We experimentally decoupled visual(corolla)and olfactory(fragrance)stimuli by presentlng paper corollas and green mesh bags,with or without a freshly-picked natural flower inside.We then contrasted the behavioral responses of roaches in these treatments with those to the natural combination of traits in actual flowers and their respective control treatments,measuring the roaches'frequency of first visits,mean and total residence time spent in each treatment.The roaches primarily used olfactory cues when approaching O.acaulis flowers at two biologically relevant spatial scaies.In addition,the presence of conspecific roaches bad a strong influence on recruitment to the expenrnental arena,increasing the statlstical differences among treatments.Our results suggest a primacy of floral fragrance over visual stimuli in the foraging responses of B.orientalis.Olfactory cues were necessary and sufficient to attract the roaches,and the visual cues presented in our manipulations only marginally increased their attraction within a 20 cm diameter of the stimulus.The full spectrum of floral visitation behavior was not elicited by the artlficial flowers,suggesting the need for addltional tactile or contact chemosensory stimuli not provided by paper.Although the nitrogenous scent compounds that we found in O.acaulis flowers are almost exclusively found in hawkmoth-pollinated flowers,the attractiveness of these compounds to a non-native,facultative flower-visiting insect indicates that they

  9. Reactivity and burnout of wood fuels

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Ora, M.

    2011-07-01

    This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile in the boiler and thereby the overall operation and efficiency of the plant. Chapter 1 consists of an introduction to thermal conversion of biomass fuels as well as a description of a Danish power plant where a measuring campaign was carried out as part of this project. Chapter 2 is a brief literature review of different aspects relevant to wood combustion, including wood structure and composition, wood pyrolysis, wood char properties and wood char oxidation. The full scale campaign, which is the subject of Chapter 3, included sampling of wood fuel before and after milling and sampling of gas and particles at the top of the combustion chamber. The collected samples and data are used to obtain an evaluation of the mills in operation at the power plant, the particle size distribution of the wood fuel, as well as the char conversion attained in the furnace. In Chapter 4 an experimental investigation on the relation between pyrolysis of wood in boiler-like conditions and wood char properties is presented. Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyser. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperature varied in the range 673-1673 K for slow pyrolysis and 1073-1573 K for fast pyrolysis. The chars were oxidised in a thermogravimetric analyser and the mass loss data were used to determine char oxidation reactivity. Char yield from fast pyrolysis (104-105 K/s) was as low as 1-6% on a dry ash free basis, whereas it was about 15-17% for slow pyrolysis (10-20 K/min); char yield decreased as

  10. Fire Reterdant Chemicals Affecting Combustion Resistance of Wood

    OpenAIRE

    Yalçın ÖRS; Sönmez, Abdullah

    1998-01-01

    Wood is an important material used in construction elements. However since it can be affected by biotic and abiotic deteriorating agents, it should be treated with chemical impregnating materials prior to use. In this study, the effects of water-soluble impregnating chemicals on the combustion resistance of wood was investigated. For this purpose, panels were prepared with oriental beech wood (Fagus orientalis L.) and pine wood (Pinus silvestris L.), which are widely used in industry. These ...

  11. SOURCES OF INNOVATION IN THE ESTONIAN FOREST AND WOOD CLUSTER

    OpenAIRE

    Kadri Ukrainski; Urmas Varblane

    2005-01-01

    The paper aims to identify the role of different sources of innovation for the Estonian wood sector. Comparing data from survey of Innovation in Estonian Enterprises 1998 2000 with similar Finnish data reveals that linkages in Estonian forest and wood cluster are relatively weaker regarding innovation sources. Universities and research institutes are the weakest part identified in the knowledge flows of the emerging Estonian wood cluster. Technological capabilities of Estonian wood and forest...

  12. Flammability Properties of Composites of Wood Fiber and Recycled Plastic

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Flammability properties of composites of wood fiber and recycled plastic were evaluated by the cone calorimeter and oxygen index chamber. Results were shown as follows: 1) Wood-PVC composite showed worse thermal stability on time to ignition (TTI) and mean heat release rate (MHRR), but better performance on heat release rate (HRR) and mean efficient heat of combustion (MEHC); wood-PP composite had better thermal stability properties, but was worse on other fire performance; 2) Compared with wood-PVC composi...

  13. Analysis of China's primary wood products market - sawnwood and plywood

    OpenAIRE

    Wan, Minli

    2009-01-01

    Department of Forest Economics, Forest products marketing China's primary wood processing industry and wood consuming sectors have experienced rapid growth in recent years. Industries like sawnwood and plywood have developed very quickly. The purpose of this study is to: 1) provide an overview of the demand, supply, imports and exports of raw wood and primary wood products in the China market between 1993 and 2007, 2) present quantitative estimates of the relative importance of factors inf...

  14. Economics of marketing wood fuel in south western Nigeria

    OpenAIRE

    OLUGBIRE O.O.; OPUTE O.H.; AREMU F.J.; OJEDOKUN C.A.; ADISA A.

    2016-01-01

    Marketing of fuel wood is an important source of livelihood for most parts of Nigeria. The study examined the economics of marketing of wood fuel in south western Nigeria with a view to determine the socio-economic characteristics of the marketers, the profitability of marketing wood fuel, the market structure and constraints to profitability. Data for the study were obtained from a total sample of 100 randomly selected wood fuel marketers through interviews schedules and application of struc...

  15. Broad iron lines in Active Galactic Nuclei

    CERN Document Server

    Fabian, A C; Reynolds, C S; Young, A J

    2000-01-01

    An intrinsically narrow line emitted by an accretion disk around a black hole appears broadened and skewed as a result of the Doppler effect and gravitational redshift. The fluorescent iron line in the X-ray band at 6.4-6.9keV is the strongest such line and is seen in the X-ray spectrum of many active galactic nuclei and, in particular, Seyfert galaxies. It is an important diagnostic with which to study the geometry and other properties of the accretion flow very close to the central black hole. The broad iron line indicates the presence of a standard thin accretion disk in those objects, often seen at low inclination. The broad iron line has opened up strong gravitational effects around black holes to observational study with wide-reaching consequences for both astrophysics and physics.

  16. Broad line regions in Seyfert-1 galaxies

    International Nuclear Information System (INIS)

    To reproduce observed emission profiles of Seyfert galaxies, rotation in an accretion disk has been proposed. In this thesis, the profiles emitted by such an accretion disk are investigated. Detailed comparison with the observed profiles yields that a considerable fraction can be fitted with a power-law function, as predicted by the model. The author analyzes a series of high quality spectra of Seyfert galaxies, obtained with the 2.5m telescope at Las Campanas. He presents detailed analyses of two objects: Mkn335 and Akn120. In both cases, strong evidence is presented for the presence of two separate broad line zones. These zones are identified with an accretion disk and an outflowing wind. The disk contains gas with very high densities and emits predominantly the lower ionization lines. He reports on the discovery of very broad wings beneath the strong forbidden line 5007. (Auth.)

  17. The wood anatomy of Gardenieae, Ixoreae and Mussaendeae (Rubiaceae)

    NARCIS (Netherlands)

    Koek-Noorman, Jifke

    1972-01-01

    The tribe Gardenieae in the restricted delimitation proposed by Bremekamp and Verdcourt is wood anatomically homogeneous. The genera of the Ixoreae studied by me also agree with each other in wood structure. Within the tribe Mussaendeae in the delimitation accepted by Schumann the wood anatomy shows

  18. Poisoned Playgrounds: Arsenic in "Pressure-Treated" Wood.

    Science.gov (United States)

    Sharp, Renee; Walker, Bill

    This study of 180 pressure-treated wood samples shows that treated wood is a much greater source of arsenic exposure for children than arsenic-contaminated drinking water. The report determines that an average 5-year-old, playing less than 2 weeks on a chromated-copper-arsenate-treated (CCA) wood play set would exceed the lifetime cancer risk…

  19. Advances and expectations of study on wood rheology

    Institute of Scientific and Technical Information of China (English)

    马远荣; 罗迎社; 李贤军

    2008-01-01

    By studying and summarizing the characteristics of wood rheology,the mathematic models of creep and mechano-sorptive creep of wood were analyzed.Rheology behaviors in process,especially drying stress and deformation set were discussed.Application of wood rheology in woodcraft process was elaborated and the research prospects and orientation were forecasted.

  20. 75 FR 75157 - Importation of Wood Packaging Material From Canada

    Science.gov (United States)

    2010-12-02

    .... 319.40-3 of the regulations lists the IPPC requirements, which include either heat treatment or... of Wood Packaging Material From Canada AGENCY: Animal and Plant Health Inspection Service, USDA... unmanufactured wood articles to remove the exemption that allows wood packaging material from Canada to enter...

  1. 7 CFR 2902.42 - Wood and concrete sealers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Wood and concrete sealers. 2902.42 Section 2902.42... Items § 2902.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage caused...

  2. Effect of technological parameters and wood properties on cutting power in plane milling of juvenile poplar wood

    Directory of Open Access Journals (Sweden)

    Barcík Štefan

    2008-10-01

    Full Text Available This paper presents the results of experimental measurements aimed at observing the effect of technological parameters (cutting speed vc and feed speed vf , type of wood (juvenile wood and mature wood andwood species (aspen Populus tremula, L. and hybrid poplar Populus x Euramericana „Serotina“ on cutting power during plane milling of poplar wood. The results showed the reduction of cutting power with the decrease of cutting speed and feed speed. Lower cutting power was also measured in milling hybrid poplar than in milling aspen. The test also confirmed the effect of different anatomical and chemical structure of juvenile wood in relation to mature wood on different physical and mechanical properties of such wood and hence also on the cutting power in processing juvenile wood.

  3. A Study of the Ultrastructure and Chemistry of Beech (Fagus grandifolia Ehrh.) Normal Wood Rays and Tension Wood Rays

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Tension wood and normal wood rays of American Beech Fagus grandifolia Ehrh. were examined by microscopy and chemical means and no significant differences were...

  4. Fourier evaluation of broad Moessbauer spectra

    International Nuclear Information System (INIS)

    It is shown by the Fourier analysis of broad Moessbauer spectra that the even part of the distribution of the dominant hyperfine interaction (hyperfine field or quadrupole splitting) can be obtained directly without using least-square fitting procedures. Also the odd part of this distribution correlated with other hyperfine parameters (e.g. isomer shift) can be directly determined. Examples for amorphous magnetic and paramagnetic iron-based alloys are presented. (author)

  5. Crx broadly modulates the pineal transcriptome

    OpenAIRE

    Rovsing, Louise; Clokie, Samuel; Bustos, Diego M.; Rohde, Kristian; Steven L Coon; Litman, Thomas; Rath, Martin F.; Møller, Morten; Klein, David C.

    2011-01-01

    Cone-rod homeobox (Crx) encodes Crx, a transcription factor expressed selectively in retinal photoreceptors and pinealocytes, the major cell type of the pineal gland. Here, the influence of Crx on the mammalian pineal gland was studied by light and electron microscopy and by use of microarray and qRTPCR technology, thereby extending previous studies on selected genes (Furukawa et al. 1999). Deletion of Crx was not found to alter pineal morphology, but was found to broadly modulate the mouse p...

  6. A Broad View of Macroeconomic Stability

    OpenAIRE

    José Antonio Ocampo

    2005-01-01

    This paper recommends a broad concept of macroeconomic stability, whereby “sound macroeconomic frameworks” include not only price stability and sound fiscal policies, but also a well-functioning real economy, sustainable debt ratios and healthy public and private sector balance sheets. These multiple dimensions imply using multiple policy instruments. The paper elaborates a framework for developing countries that involves active use of counter-cyclical macroeconomic policies (exchange rate, m...

  7. Relativistic redshifts in quasar broad lines

    CERN Document Server

    Tremaine, Scott; Liu, Xin; Loeb, Abraham

    2014-01-01

    The broad emission lines commonly seen in quasar spectra have velocity widths of a few per cent of the speed of light, so special- and general-relativistic effects have a significant influence on the line profile. We have determined the redshift of the broad H-beta line in the quasar rest frame (determined from the core component of the [OIII] line) for over 20,000 quasars from the Sloan Digital Sky Survey DR7 quasar catalog. The mean redshift as a function of line width is approximately consistent with the relativistic redshift that is expected if the line originates in a randomly oriented Keplerian disk that is obscured when the inclination of the disk to the line of sight exceeds ~30-45 degrees, consistent with simple AGN unification schemes. This result also implies that the net line-of-sight inflow/outflow velocities in the broad-line region are much less than the Keplerian velocity when averaged over a large sample of quasars with a given line width.

  8. WOOD-WATER RELATIONSHIPS AND BIOLOGICAL DURABILITY OF HEAT-TREATED TAURUS FIR WOOD

    Directory of Open Access Journals (Sweden)

    Bekir Cihad BAL

    2015-09-01

    Full Text Available In this study, Taurus Fir (Abies cilicica wood was treated with hot air at temperatures of 160, 190 and 220°C for 2h durations. After heat treatment, some physical properties and wood-water relationships were evaluated, such as mass loss, density, tangential swelling, radial swelling, volumetric swelling, swelling anisotropy, and fiber saturation point. In addition, the biological durability of Taurus Fir wood was tested in the laboratory with the soil contact test, and determined weight loss. The relationships between mass loss and some of the tested properties were determined using regression analysis. The results showed that heat treatment at 220°C had significant effects on the physical properties and the biological durability of Taurus Fir wood. Further, it was determined that there was a linear-negative correlation between weight loss and mass loss.

  9. Merkwaardige verschijnselen bij Dictyosphaerium pulchellum Wood

    NARCIS (Netherlands)

    Schroevers, P.J.; Roest, A.C.F.

    1967-01-01

    In a shallow pond, dug in an oligotrophic area, but enriched by recreation, a waterbloom of a micro-organism which at first could not be identified was investigated. Cultivation showed a transformation into distinct colonies of Dictyosphaerium pulchellum Wood, which species was repeatedly recorded f

  10. Boron impregnation treatment of Eucalyptus grandis wood.

    Science.gov (United States)

    Dhamodaran, T K; Gnanaharan, R

    2007-08-01

    Eucalyptus grandis is suitable for small timber purposes, but its wood is reported to be non-durable and difficult to treat. Boron compounds being diffusible, and the vacuum-pressure impregnation (VPI) method being more suitable for industrial-scale treatment, the possibility of boron impregnation of partially dry to green timber was investigated using a 6% boric acid equivalent (BAE) solution of boric acid and borax in the ratio 1:1.5 under different treatment schedules. It was found that E. grandis wood, even in green condition, could be pressure treated to desired chemical dry salt retention (DSR) and penetration levels using 6% BAE solution. Up to a thickness of 50mm, in order to achieve a DSR of 5 kg/m(3) boron compounds, the desired DSR level as per the Indian Standard for perishable timbers for indoor use, it was found that neither the moisture content of wood nor the treatment schedule posed any problem as far as the treatability of E. grandis wood was concerned. PMID:17046244

  11. Narrative Arts in Death in the Woods

    Institute of Scientific and Technical Information of China (English)

    陈雪姐; 郭清泉

    2013-01-01

      As a transitionary writer of modernist American literature, Sherwood Anderson exemplified his characteristic narrative arts in his master piece Death in the Woods. Through direct authorial address to the reader, a circular, not linear narrative structure and simple vocabulary, Anderson disclosed the truth that he wanted to convey to the readers in his unique way.

  12. Relations Between Permeability and Structure of Wood

    Institute of Scientific and Technical Information of China (English)

    Bao Fucheng; Zhao Youke; Lü Jianxiong

    2003-01-01

    The permeability and the structure of heartwood and sapwood of the solvent-exchange dried and the air-dried green-wood of Chinese-fir (Cunninghamia lanceolata (Lamb.) Hook.) and masson pine (Pinus massoniana Lamb.) were measured inorder to study the relations between the permeability and the structure. The results showed that the permeability of sapwood of boththe air-dried and the solvent-exchange dried wood was higher than that of heartwood, and the permeability of the solvent-exchangeddried heartwood and sapwood was higher than that of the air-dried. A higher permeability of wood was attributed to, on the one hand,a bigger number of flow path per unit area of the wood perpendicular to the flow direction resulted from a bigger number ofunaspirated pits per unit area and a bigger number of effective pit openings per membrane, and on the other hand, a smaller numberof tracheid in series connection per unit length parallel to flow direction resulted from a longer tracheid length and an effectivetracheid length for permeability.

  13. Wood anatomy of the Blakeeae (Melastomataceae)

    NARCIS (Netherlands)

    Koek-Noorman, J.; Hogeweg, P.; Maanen, van W.H.M.; Welle, ter B.J.H.

    1979-01-01

    The present paper deals with the wood anatomy of the Blakeeae (Melastomataceae). Generic descriptions of the secondary xylem of Blakea, Topobea, and Huilaea are given and compared with data on 16 genera of the Miconieae. Numerical pattern detection was undertaken. The results confirm our preliminary

  14. Kuidas tuua Eestisse Tiger Woods / Raul Ranne

    Index Scriptorium Estoniae

    Ranne, Raul

    2008-01-01

    Reaalselt arvestades on tõenäosus, et Eestit väisab golfistaar Tiger Woods, muidugi olematu. Teoreetiliselt on see siiski võimalik. Vestlusest Jõelähtme golfiväljakut opereeriv Estonian Golf Country Clubi presidendi Mait Schmidtiga

  15. Evaluation Study of VTAE Wood Technics Programs.

    Science.gov (United States)

    Wisconsin State Board of Vocational, Technical, and Adult Education, Madison.

    A survey of former students of the Wisconsin Vocational, Technical, and Adult Education (VTAE) wood technics programs and employers in woodworking industries was conducted during spring of 1985. General objectives were to determine job classifications, types of businesses, and relative importance of tasks or duties in various woodworking-related…

  16. Dust exposures in the wood processing industry.

    Science.gov (United States)

    Alwis, U; Mandryk, J; Hocking, A D; Lee, J; Mayhew, T; Baker, W

    1999-01-01

    Workers at four different woodworking processes--two logging sites, four sawmills, one major woodchipping operation, and five joineries situated in the state of New South Wales in Australia--were studied for personal inhalable dust exposures (N = 182). The geometric mean exposure at logging sites was 0.6 mg/m3 (N = 7), sawmills 1.6 mg/m3 (N = 93), woodchipping 1.9 mg/m3 (N = 9), and joineries 3.7 mg/m3 (N = 66). Overall, 62% of the exposures exceeded the current standards. Among joineries, 95% of the hardwood exposures and 35% of the softwood exposures were above the relevant standards. A majority of workers (approximately 90%) did not wear appropriate respirators approved for wood dust, while the ones who did wear them, used them on average less than 50% of the time. The significant determinants of personal wood dust exposures (n = 163) were found to be local exhaust ventilation, job title, use of handheld tools, cleaning method used, use of compressed air, and green or dry wood processed. Type of wood processed (softwood or hardwood) was not found to be statistically significant.

  17. Wood gasification system for electricity production

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Heijden, S.; Szladow, A.J.; Barabas, M.; Sirianni, G.

    1981-08-01

    A 65 kVA generation system using wood gasification for electricity production has been tested. The system efficiency, operability and response to load variations was determined. For a range of electric output from 5 to 45 kW, the overall efficiency varied from 9 to 20 percent. Changes in gas composition with load variation did not affect gas heating values. 3 refs.

  18. Adhesives; A Base Syllabus on Wood Technology.

    Science.gov (United States)

    Eastern Kentucky Univ., Richmond.

    Prepared by participants in the 1968 National Defense Education Act Institute on Wood Technology, this syllabus is one of a series of basic outlines designed to aid college level industrial arts instructors in improving and broadening the scope and content of their programs. The guide is divided into three sections, the first of which deals with…

  19. Duration of load effects of solid wood

    DEFF Research Database (Denmark)

    Svensson, Staffan

    Test methods for studying the effect of long-term loading on the load carrying capacity of structural wood are discussed. The impact of sampling procedures on test results is investigated and is exemplified. It is concluded from this investigation that the sampling method has a significant impact...

  20. Anisotropy of Wood in the Microwave Region

    Science.gov (United States)

    Ziherl, Sasa; Bajc, Jurij; Urankar, Bernarda; Cepic, Mojca

    2010-01-01

    Wood is transparent for microwaves and due to its anisotropic structure has anisotropic dielectric properties. A laboratory experiment that allows for the qualitative demonstration and quantitative measurements of linear dichroism and birefringence in the microwave region is presented. As the proposed experiments are based on the anisotropy (of…

  1. Modelling piloted ignition of wood and plastics

    NARCIS (Netherlands)

    Blijderveen, van M.; Bramer, E.A.; Brem, G.

    2012-01-01

    To gain insight in the startup of an incinerator, this article deals with piloted ignition. A newly developed model is described to predict the piloted ignition times of wood, PMMA and PVC. The model is based on the lower flammability limit and the adiabatic flame temperature at this limit. The inco

  2. Milnor-Wood inequalities for products

    CERN Document Server

    Bucher, Michelle

    2012-01-01

    We prove Milnor-Wood inequalities for local products of manifolds. As a consequence, we establish the generalized Chern Conjecture for products $M\\times \\Sigma^k$ for any product of a manifold $M$ with a product of $k$ copies of a surface $\\Sigma$ for $k$ sufficiently large.

  3. NeighbourWoods for Better Cities

    DEFF Research Database (Denmark)

    Konijnendijk, Cecil Cornelis; Schipperijn, Jasper Jan

    This publication aims to contribute to the development af NeighbourWoods through socially-inclusive planning, design and management. It presents experiences from an international project supported by the European Commission which evaluated and developed approaches and tools to assist NeighbourWoo...

  4. Wood energy Technology Program; Puuenergian teknologiaohjelma

    Energy Technology Data Exchange (ETDEWEB)

    Hakkila, P. [VTT Energy, Espoo (Finland)

    1999-07-01

    The National Wood Energy Technology Program focuses on developing the production technology and improving the quality of forest chips from logging residues and small- sized trees. In 1998, energy use of forest chips in Finland amounted to 0.5 million solid-m{sup 3}. The main research areas of the program are: integration of energy production into industrial wood production in the conventional forestry; development of planning and logistics in the production and storage of forest chips; development of technology for chipping, handling and storage including operations at chip terminals and at the end-users facilities; development of long-distance transport of fuel chips and unchipped forest residues; preparing forest machine and truck contractors for the production of forest chips on a large scale; development of quality control to improve the heat value of the chips; and the operational reliability of wood chip-fired plants improving the handling and combustion properties of bark, sawdust and other solid wood residues from forest industry. The total budget for 1999 - 2003 is million FIM 250, Tekes' share of which amounts to million FIM 50.

  5. Chemical Composition, Antioxidant, and Antibacterial Activity of Wood Vinegar from Litchi chinensis.

    Science.gov (United States)

    Yang, Jyh-Ferng; Yang, Cheng-Hong; Liang, Ming-Tsai; Gao, Zi-Jie; Wu, Yuh-Wern; Chuang, Li-Yeh

    2016-01-01

    The antioxidant and antibacterial activities of wood vinegar from Litchi chinensis, and its components have been studied. The chemical compositions of wood vinegar were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 17 chemical compounds were identified, representing 83.96% of the compositions in the wood vinegar. Three major components, included 2,6-dimethoxyphenol (syringol, 29.54%), 2-methoxyphenol (guaiacol, 12.36%), and 3,5-dimethoxy-4-hydroxytoluene (11.07%), were found in the wood vinegar. Antioxidant activities of the acids were investigated from the aspects of 1,1-Diphyl-2-picrylhydrazyl (DPPH) free radicals scavenging capacity, superoxide anion radical scavenging capacity, and reducing power. The pyroligneous acid exhibited high antioxidant activity which was comparable to the reference standards (vitamin C and butylated hydroxyl toluene) at the same dose with IC50 values of 36.5 ppm calculated by the DPPH radical scavenging assay, 38.38 g Trolox equivalent/100 g DW by the trolox equivalent antioxidant capacity (TEAC) assay, and 67.9 by the reducing power analysis. Antibacterial activity was evaluated using the disc diffusion and microdilution methods against a group of clinically antibiotic resistant isolates. The major components exhibited broad spectrum inhibition against all the bacterial strains with a range of disc inhibition zoon between 15-19 mm. The minimum inhibition concentration and minimum bactericide concentration against the test strains was ranging in 0.95-3.80 μL/100 μL and 1.90-3.80 μL/100 μL, respectively. Most of the antibiotic resistant strains were more susceptible to the wood vinegar than the non-antibiotic resistant strain except the strain of ornithine resistant Staphylococcus aureus. Based on the chemical profile, it was considered that the strongest antioxidant and antibacterial activity of Litchi chinensis wood vinegar was due to its highly phenolic compositions. This study revealed that the Litchi

  6. Chemical Composition, Antioxidant, and Antibacterial Activity of Wood Vinegar from Litchi chinensis

    Directory of Open Access Journals (Sweden)

    Jyh-Ferng Yang

    2016-08-01

    Full Text Available The antioxidant and antibacterial activities of wood vinegar from Litchi chinensis, and its components have been studied. The chemical compositions of wood vinegar were analyzed by gas chromatography-mass spectrometry (GC-MS. A total of 17 chemical compounds were identified, representing 83.96% of the compositions in the wood vinegar. Three major components, included 2,6-dimethoxyphenol (syringol, 29.54%, 2-methoxyphenol (guaiacol, 12.36%, and 3,5-dimethoxy-4-hydroxytoluene (11.07%, were found in the wood vinegar. Antioxidant activities of the acids were investigated from the aspects of 1,1-Diphyl-2-picrylhydrazyl (DPPH free radicals scavenging capacity, superoxide anion radical scavenging capacity, and reducing power. The pyroligneous acid exhibited high antioxidant activity which was comparable to the reference standards (vitamin C and butylated hydroxyl toluene at the same dose with IC50 values of 36.5 ppm calculated by the DPPH radical scavenging assay, 38.38 g Trolox equivalent/100 g DW by the trolox equivalent antioxidant capacity (TEAC assay, and 67.9 by the reducing power analysis. Antibacterial activity was evaluated using the disc diffusion and microdilution methods against a group of clinically antibiotic resistant isolates. The major components exhibited broad spectrum inhibition against all the bacterial strains with a range of disc inhibition zoon between 15–19 mm. The minimum inhibition concentration and minimum bactericide concentration against the test strains was ranging in 0.95–3.80 μL/100 μL and 1.90–3.80 μL/100 μL, respectively. Most of the antibiotic resistant strains were more susceptible to the wood vinegar than the non-antibiotic resistant strain except the strain of ornithine resistant Staphylococcus aureus. Based on the chemical profile, it was considered that the strongest antioxidant and antibacterial activity of Litchi chinensis wood vinegar was due to its highly phenolic compositions. This study revealed

  7. Fast Curing of Composite Wood Products

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Arthur J. Ragauskas

    2006-04-26

    The overall objective of this program is to develop low temperature curing technologies for UF and PF resins. This will be accomplished by: • Identifying the rate limiting UF and PF curing reactions for current market resins; • Developing new catalysts to accelerate curing reactions at reduced press temperatures and times. In summary, these new curing technologies will improve the strength properties of the composite wood products and minimize the detrimental effects of wood extractives on the final product while significantly reducing energy costs for wood composites. This study is related to the accelerated curing of resins for wood composites such as medium density fiberboard (MDF), particle board (PB) and oriented strandboard (OSB). The latter is frequently manufactured with a phenol-formaldehyde resin whereas ureaformaldehyde (UF) resins are usually used in for the former two grades of composite wood products. One of the reasons that hinder wider use of these resins in the manufacturing of wood composites is the slow curing speed as well as inferior bondability of UF resin. The fast curing of UP and PF resins has been identified as an attractive process development that would allow wood to be bonded at higher moisture contents and at lower press temperatures that currently employed. Several differing additives have been developed to enhance cure rates of PF resins including the use of organic esters, lactones and organic carbonates. A model compound study by Conner, Lorenz and Hirth (2002) employed 2- and 4-hydroxymethylphenol with organic esters to examine the chemical basis for the reported enhanced reactivity. Their studies suggested that the enhance curing in the presence of esters could be due to enhanced quinone methide formation or enhanced intermolecular SN2 reactions. In either case the esters do not function as true catalysts as they are consumed in the reaction and were not found to be incorporated in the polymerized resin product. An

  8. Wood torrefaction. Pilot tests and utilisation prospects

    Energy Technology Data Exchange (ETDEWEB)

    Wilen, C.; Jukola, P.; Jarvinen, T.; Sipila, K. [VTT Technical Reseach Centre of Finland, Espoo (Finland); Verhoeff, F.; Kiel, J. [Energy research Centre of the Netherlands, LE Petten (Netherlands)

    2013-09-15

    The research project 'Torrefaction of woody biomasses as energy carriers for the European markets' was carried out within the Tekes BioRefine programme in 2010-2012 and was coordinated by VTT. The main objective of the project was to create a discussion platform and collate basic information for the Finnish industrial stakeholders involved in developing torrefaction technology or planning to include torrefied biomass in their fuel supply for energy production. Given the availability of torrefaction pilot facilities in Europe, it was decided at an early phase of the national torrefaction research project not to build and operate separate pilot equipment, and thus save time and money. Experimental research was conducted in cooperation with ECN, The Netherlands. Finnish wood chips and crushed forest residue were tested at different torrefaction temperatures in the PATRIG torrefaction test rig with great success, and large quantities of torrefied wood chips and pellets were produced. CFD simulation work was carried out at VTT to investigate the feasibility of torrefied fuels to replace part of the coal. From the combustion point of view it seems feasible to replace coal by torrefied wood biomass with shares up to 50% by weight. Basic, small-scale experiments were carried out to compare torrefied wood pellets with conventional wood and straw pellets with regard to their handling and storage properties. The experiments showed that the torrefied pellets are clearly more hydrophobic than wood and straw pellets and do not disintegrate completely on exposure to water. A study on dust explosion and self-ignition characteristics indicated that the torrefied dust does not differ significantly from the normal biomass dust, but is clearly more reactive than coal dust. Commercial development of torrefaction is currently in its early phase. The current general view is that most of the demonstration plants have technical problems, which have delayed their commercial

  9. The influence of irradiated wood filler on some properties of polypropylene - wood composites

    Directory of Open Access Journals (Sweden)

    Điporović-Momčilović Milanka

    2007-01-01

    Full Text Available The problem of compatibility between the wood filler and thermoplastic matrix is of essential importance in composite production. Numerous methods have been developed for increasing this compatibility, which is still representing a challenging objective of composite research throughout the world. The research into these methods is primarily directed towards their efficiency from the viewpoint of the composite performance and their economical acceptability. The latter is of particular importance for the composite production in the developing countries with respect to the shortage of the corresponding funds. With this respect, the utilization of ionizing radiation might have considerable advantages. In this research, the beech wood flour was irradiated by a dose of 10 kGy of 60Co gamma rays for purpose of provoking the changes by the ionizing effect. The effects of ionizing radiation upon the properties of wood particles have been examined by IR spectroscopy and by determination of contents of hydroxyl groups in wood by acetylating as an indirect method. All these methods have been expected to reveal the chemical effects of the applied radiation treatment. The irradiated and the control wood flour were used in order to produce the samples of composite with polypropylene. The polypropylene-wood flour (PP-WF composites were produced with 40% of wood particles having fraction size 0.3 mm. The melt-blended composites were modified with amido-acrylic acid (AMACA as a new coupling agent synthesized for this propose in amount of 6 wt.% (based on wood filler and successively with 0.05 wt.% (based on PP of organic peroxide during mixing step. The composites containing coupling agents showed superior mechanical properties, compared to the untreated one. The highest extent of improvement of tensile was achieved in PP-WFl composites modified with AMACA coupling agent.

  10. Moisture-Cure Polyurethane Wood Adhesives: Wood/Adhesive Interactions and Weather Durability

    OpenAIRE

    Ren, Dakai

    2010-01-01

    This project addresses two main subjects of moisture-cure polyurethane (PUR) wood adhesives: wood/PUR interactions and structure-property behavior emphasizing on weather durability. For these purposes, one simplified model PUR (MPUR) and three more commercially significant PURs (CPURs) with different hard segment contents were prepared. Separately, an early side project involved the synthesis of a 13C and 15N double-labeled polymeric methylenebis(phenylisocyanate) (pMDI) resin; this was use...

  11. Genetic improvement of trees for wood production, with particular refeference to wood traits

    OpenAIRE

    Nocetti M

    2008-01-01

    The use of selected propagation material from tree improvement programs is expected to lead to a more homogenous product, generally appreciated by industry. So far, breeding strategy have been mainly targeted to maximize acclimation/adaptation to specific environment conditions, tree growth and disease resistance, but it is not obvious that such strategy might lead to improvement of wood characteristics at the same time. Therefore, it seems important to introduce wood traits improvement as sp...

  12. Exposure to wood dust and heavy metals in workers using CCA pressure-treated wood.

    Science.gov (United States)

    Decker, Paul; Cohen, Beverly; Butala, John H; Gordon, Terry

    2002-01-01

    Chemical pesticide treatment enables relatively nonresistant woods to be used in outdoor construction projects. The most prevalent procedure used to protect these woods is pressure treatment with chromium, copper, and arsenic (CCA). This pilot study examined the airborne concentration and particle size distribution of wood particles, chromium, copper, and arsenic at both outdoor (measured over the whole work day) and indoor (measured during the performance of specific tasks) work sites. At the outdoor residential deck construction sites, the arithmetic mean total dust concentration, measured using personal filter cassette samplers, was 0.57 mg/m3. The mass median aerodynamic diameter (da) of the outdoor wood dust was greater than 20 microm. Indoor wood dust concentrations were significantly greater than those measured outdoor and were job category-dependent. The highest mean breathing zone dust concentration, 49.0 mg/m3, was measured at the indoor sanding operation. Personal impactor sampling demonstrated that the mean total airborne concentration of arsenic, but not chromium or copper, was consistently above recommended occupational exposure levels at the indoor work site, and occasionally at the outdoor work sites. At the indoor sanding operation, the mean total chromium, copper, and arsenic concentrations were 345, 170, and 342 microg/m3, respectively. Thus, significant exposure to airborne heavy metals can occur as a result of indoor and outdoor exposure to CCA pressure-treated wood dust. Therefore, current standards for wood dust may not adequately protect workers from the heavy metals commonly used in CCA pressure-treated wood.

  13. Signature wood modifications reveal decomposer community history.

    Directory of Open Access Journals (Sweden)

    Jonathan S Schilling

    Full Text Available Correlating plant litter decay rates with initial tissue traits (e.g. C, N contents is common practice, but in woody litter, predictive relationships are often weak. Variability in predicting wood decomposition is partially due to territorial competition among fungal decomposers that, in turn, have a range of nutritional strategies (rot types and consequences on residues. Given this biotic influence, researchers are increasingly using culture-independent tools in an attempt to link variability more directly to decomposer groups. Our goal was to complement these tools by using certain wood modifications as 'signatures' that provide more functional information about decomposer dominance than density loss. Specifically, we used dilute alkali solubility (DAS; higher for brown rot and lignin:density loss (L:D; higher for white rot to infer rot type (binary and fungal nutritional mode (gradient, respectively. We first determined strength of pattern among 29 fungi of known rot type by correlating DAS and L:D with mass loss in birch and pine. Having shown robust relationships for both techniques above a density loss threshold, we then demonstrated and resolved two issues relevant to species consortia and field trials, 1 spatial patchiness creating gravimetric bias (density bias, and 2 brown rot imprints prior or subsequent to white rot replacement (legacy effects. Finally, we field-tested our methods in a New Zealand Pinus radiata plantation in a paired-plot comparison. Overall, results validate these low-cost techniques that measure the collective histories of decomposer dominance in wood. The L:D measure also showed clear potential in classifying 'rot type' along a spectrum rather than as a traditional binary type (brown versus white rot, as it places the nutritional strategies of wood-degrading fungi on a scale (L:D=0-5, in this case. These information-rich measures of consequence can provide insight into their biological causes, strengthening the

  14. Signature wood modifications reveal decomposer community history.

    Science.gov (United States)

    Schilling, Jonathan S; Kaffenberger, Justin T; Liew, Feng Jin; Song, Zewei

    2015-01-01

    Correlating plant litter decay rates with initial tissue traits (e.g. C, N contents) is common practice, but in woody litter, predictive relationships are often weak. Variability in predicting wood decomposition is partially due to territorial competition among fungal decomposers that, in turn, have a range of nutritional strategies (rot types) and consequences on residues. Given this biotic influence, researchers are increasingly using culture-independent tools in an attempt to link variability more directly to decomposer groups. Our goal was to complement these tools by using certain wood modifications as 'signatures' that provide more functional information about decomposer dominance than density loss. Specifically, we used dilute alkali solubility (DAS; higher for brown rot) and lignin:density loss (L:D; higher for white rot) to infer rot type (binary) and fungal nutritional mode (gradient), respectively. We first determined strength of pattern among 29 fungi of known rot type by correlating DAS and L:D with mass loss in birch and pine. Having shown robust relationships for both techniques above a density loss threshold, we then demonstrated and resolved two issues relevant to species consortia and field trials, 1) spatial patchiness creating gravimetric bias (density bias), and 2) brown rot imprints prior or subsequent to white rot replacement (legacy effects). Finally, we field-tested our methods in a New Zealand Pinus radiata plantation in a paired-plot comparison. Overall, results validate these low-cost techniques that measure the collective histories of decomposer dominance in wood. The L:D measure also showed clear potential in classifying 'rot type' along a spectrum rather than as a traditional binary type (brown versus white rot), as it places the nutritional strategies of wood-degrading fungi on a scale (L:D=0-5, in this case). These information-rich measures of consequence can provide insight into their biological causes, strengthening the links

  15. XPS characterization of naturally aged wood

    Science.gov (United States)

    Popescu, Carmen-Mihaela; Tibirna, Carmen-Mihaela; Vasile, Cornelia

    2009-12-01

    Wood deterioration over time (by a simultaneously biological, chemical or physical attack) is an inevitable continuous process in the environment. This process destroys all heritage resulting in a loss of valuable old wooden structures and their properties. What type of deterioration occurs and how these processes impact the wood are important questions that need consideration if old wooden structures are to be studied and properly preserved. X-ray photoelectron spectroscopy (XPS) was employed to analyze the undegraded (sound wood of ˜6 years) and degraded lime wood (˜150 years, ˜180 years, ˜250 years) from painting supports, differing in terms of the provenance, conservation status and environmental conditions of storage. Elaborated XPS analysis (comparison of C and O individual spectra, decomposition for each atomic component, calculation of O/C ratio) provided a view of the composition of the sample surfaces analyzed. On the basis of these results, it was confirmed that significant changes occurred in the first period of ageing, the ˜150 years lime wood sample having the highest percent of the carbon atoms and the lowest percentage of oxygen atoms and, respectively O/C ratio. According to our previous studies (X-ray diffraction, FTIR spectroscopy, analytical pyrolysis combined with gas chromatography/mass spectrometry and ESR-spectroscopy results), these features could be attributed to the fact that hemicelluloses and amorphous cellulose are degraded in time, whereas the crystalline fraction of cellulose decreases more slowly than the amorphous one. Consequently, the observation may be made that lignin is not so easily degraded under the environmental conditions where paintings are frequently exposed.

  16. Dry vs soaked wood: modulating the volatile extractible fraction of oak wood by heat treatments.

    Science.gov (United States)

    Duval, Charlie J; Sok, Nicolas; Laroche, Jérémy; Gourrat, Karine; Prida, Andréi; Lequin, Sonia; Chassagne, David; Gougeon, Régis D

    2013-05-01

    The aim of this study was to analyze the impact of the water content of wood on the concentrations of volatile compounds which can be extracted after heat treatments. Head Space-Solid Phase Micro Extraction Gas Chromatography coupled to Mass Spectrometry (HS-SPME GC-MS) has been used to compare the concentrations of six aroma compounds (vanillin, furfural, eugenol, guaïacol and cis- and trans-whisky lactones) in hydroalcoholic extracts of heated oak wood samples either previously soaked in hot water or not. Except for eugenol, concentrations of extracted aromas appeared to be lower in soaked woods than in dry woods for temperatures up to 200 °C. If a delaying effect of water could explain such overall lower extracted concentrations from soaked woods, a PCA analysis revealed that for the longer duration (25 min of heat treatment), the adsorbed water could promote a higher impact of furfural, eugenol and both whisky lactones on the composition of hydroalcoholic extracts, suggesting that alternative mechanisms of thermal modifications of the wood macromolecular network could exist at high temperatures in presence of adsorbed water.

  17. Demineralization of wood using wood-derived acid: Towards a selective pyrolysis process for fuel and chemicals production

    NARCIS (Netherlands)

    Oudenhoven, S.R.G; Westerhof, R.J.M.; Aldenkamp, N.; Brilman, D.W.F.; Kersten, S.R.A.

    2013-01-01

    A process concept for the pyrolysis of demineralized wood to obtain high organic and especially levoglucosan yields is proposed and tested experimentally. The wood is demineralized using organic acids, produced and concentrated within the same pyrolysis process. Pine wood was pyrolyzed in a fluidiz

  18. To Broad-Match or Not to Broad-Match : An Auctioneer's Dilemma ?

    CERN Document Server

    Singh, Sudhir Kumar

    2008-01-01

    We initiate the study of an interesting aspect of sponsored search advertising, namely the consequences of broad match-a feature where an ad of an advertiser can be mapped to a broader range of relevant queries, and not necessarily to the particular keyword(s) that ad is associated with. Starting with a very natural setting for strategies available to the advertisers, and via a careful look through algorithmic and complexity theoretic glasses, we first propose a solution concept called broad match equilibrium(BME) for the game originating from the strategic behavior of advertisers as they try to optimize their budget allocation across various keywords. Next, we consider two broad match scenarios based on factors such as information asymmetry between advertisers and the auctioneer, and the extent of auctioneer's control on the budget splitting. In the first scenario, the advertisers have the full information about broad match and relevant parameters, and can reapportion their own budgets to utilize the extra i...

  19. The use of wood waste for energy production

    International Nuclear Information System (INIS)

    The paper presents some technical aspects and management issues of wood waste reuse end disposal. It refers to the Greek and European legislation which determines the framework for rational and environmental friendly practices for woos waste management. It refers also to the wood waste classification systems and the currently applied methods of wood waste disposal and reuse. Emphasis is given to the wood waste-to-energy conversion system, particularly to the pretreatment requirements, the combustion techniques, and the environmental constrains. Finally, the decision making process for the investments in the wood waste firing thermal units is discussed

  20. Wood fuel markets in Northern Europe. Price formation and internationalization

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Olle

    2012-07-01

    High fossil fuel prices and ambitions to reduce greenhouse gas emissions have increased demand for renewable energy and are changing wood fuel market structures. Wood fuels are to a rapidly growing degree used in industrial proportions and traded in commercial markets. Wood fuels are seen as a key component to achieve policy goals related to climate change, especially in the EU. In the six papers that form the basis for this thesis, prices of wood fuels in Northern Europe are analyzed by means of time series analysis to increase understanding about the factors that govern market development. In Paper I, it is found that whereas the Austrian and German residential-quality wood pellet markets are integrated, Sweden is a separate market. The conclusion from Paper II is that despite a long history of trade in wood fuels between Estonia and Sweden, the two markets cannot be considered integrated. The results from Paper III indicate that refined and unrefined wood fuels should be seen as two separate markets, and that forest chips prices follow different trajectories depending on whether they are used in district heating or in forest industries. In Paper IV, it is acknowledged that although high and volatile oil prices are an important driver for the growth in demand for wood fuels, no significant spillover from oil price developments into Swedish wood fuel prices could be discerned in the time period 1993-2010. In Paper V, the conclusion is that prices of industrial roundwood and unrefined wood fuels followed a common trend in Sweden in the first decade of the 21st century. Paper VI shows that there is a significantly higher level of market maturity and internationalization in the Danish wood pellet market compared to the wood chip market in the country. In conclusion, this thesis uncovers some of the mechanisms that affect wood fuel markets, including the differences between unrefined wood fuels - such as wood chips - and the dynamic market for wood pellets. Whereas

  1. Energy use of decayed wood; Lahopuun maeaerae, sisaeltoe ja hankintakustannukset

    Energy Technology Data Exchange (ETDEWEB)

    Maekelae, M.; Lipponen, K. [Metsaeteho Oy, Helsinki (Finland)

    1997-12-01

    A study of the quality, amounts and delivery costs of decayed wood available for possible energy use will be carried out in co-operation by Metsaeteho and Forest Research Institute. The work will consist of the following sub-studies: Quality of decayed wood available for possible energy use, quantities of decayed wood available for possible energy use by municipalities in Western and Southern Finland, harvesting, transport and chipping costs of decayed wood in different delivery alternatives and as a practical example, quantities of decayed wood available for possible energy use in two potential consumption municipalities. (orig.)

  2. Wood pellets : is it a reliable, sustainable, green energy option?

    International Nuclear Information System (INIS)

    The Wood Pellet Association of Canada was formerly called the BC Pellet Fuel Manufacturers Association, and was renamed and re-organized in January 2006. The association serves as an advocate for the wood pellet industry in addition to conducting research projects. This power point presentation presented an overview of the wood pellet industry in North America and Europe. Canada's 23 pellet plants currently produce just over 1,000,000 tons of wood pellets annually. Pellet producers in the United States produce approximately 800,000 tons annually for the residential bagged market. There are currently 240 pellet plants in Europe, and district heating is the largest growth market for wood pellets in Europe. British Columbia (BC) pellet producers will ship 450,000 tons to European power plants in 2005. Wood pellet specifications were presented, with details of calorific values, moisture and ash contents. An outline of wood pellet production processes was provided. New pellet plants currently under construction were reviewed. Domestic, North American and overseas exports were discussed, along with production estimates for BC for the next 5 years. A chart of world production and consumption of wood pellets between 2000 to 2010 was presented. North American wood pellet technologies were described. The impact of the pine beetle infestation in BC on the wood pellet industry was evaluated, and a worldwide wood pellet production growth forecast was presented. Issues concerning off-gassing, emissions, and torrifracation were also discussed. tabs., figs

  3. Penetration and Effectiveness of Micronized Copper in Refractory Wood Species

    Science.gov (United States)

    Civardi, Chiara; Van den Bulcke, Jan; Schubert, Mark; Michel, Elisabeth; Butron, Maria Isabel; Boone, Matthieu N.; Dierick, Manuel; Van Acker, Joris; Wick, Peter; Schwarze, Francis W. M. R.

    2016-01-01

    The North American wood decking market mostly relies on easily treatable Southern yellow pine (SYP), which is being impregnated with micronized copper (MC) wood preservatives since 2006. These formulations are composed of copper (Cu) carbonate particles (CuCO3·Cu(OH)2), with sizes ranging from 1 nm to 250 μm, according to manufacturers. MC-treated SYP wood is protected against decay by solubilized Cu2+ ions and unreacted CuCO3·Cu(OH)2 particles that successively release Cu2+ ions (reservoir effect). The wood species used for the European wood decking market differ from the North American SYP. One of the most common species is Norway spruce wood, which is poorly treatable i.e. refractory due to the anatomical properties, like pore size and structure, and chemical composition, like pit membrane components or presence of wood extractives. Therefore, MC formulations may not suitable for refractory wood species common in the European market, despite their good performance in SYP. We evaluated the penetration effectiveness of MC azole (MCA) in easily treatable Scots pine and in refractory Norway spruce wood. We assessed the effectiveness against the Cu-tolerant wood-destroying fungus Rhodonia placenta. Our findings show that MCA cannot easily penetrate refractory wood species and could not confirm the presence of a reservoir effect. PMID:27649315

  4. Factors Affecting the Resinification of Liquefied Phenolated Wood

    Institute of Scientific and Technical Information of China (English)

    Zhang Qiu-hui; Zhao Guang-jie1; Hu Shi-yu

    2005-01-01

    Wood of Chinese fir and poplar were liquefied in phenol at 150℃ and atmospheric pressure. The liquefied wood were reacted with formaldehyde to synthesize the liquefied wood-based resin. The factors affecting the resinification and the properties of new resin were investigated. The results show that the formaldehyde/liquefied wood molar ratio, reaction temperature, reaction time and sodium hydroxide/liquefied wood molar ratio have important influence on the resin characteristics. With the increase of formaldehyde/liquefied wood molar ratio, the yield of resin increases, and the free phenol content of resins decreases, showing that the resinification of liquefied wood is more complete at higher formaldehyde/liquefied wood molar ratios. The reaction temperature on the viscosity of the liquefied resin has considerable effect; the viscosity of resin increased with increasing reaction temperature,and the amount of liquefied poplar resin increased more quickly than that of liquefied Chinese fir resin. The resinification time also has obvious influence on the viscosity of resin; the viscosity of liquefied poplar resin is more sensitive to resinification time compared with that of liquefied Chinese fir. The amount of sodium hydroxide can improve the water miscibility of liquefied wood resin.The optimum sodium hydroxide/liquefied wood molar ratio for preparation of liquefied wood-based resins exceeds 0.4.

  5. Health effects assessment of exposure to particles from wood smoke

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Elsa; Dybdahl, M. (Technical Univ. of Denmark, National Food Institute, Dept. of Toxicology and Risk Assessment, Soeborg (Denmark)); Larsen, Poul Bo (Danish Environmental Protection Agency, Copenhagen (Denmark))

    2008-07-01

    The number of residential wood burning devices has increased in Denmark during the latest years and it has been estimated that there in 2005 were about 551,000 wood stoves and about 48,000 wood boilers in Denmark. This has resulted in an increased exposure of the general Danish population to pollutants associated with residential wood smoke. New Danish monitoring results on particulate matter (PM) in ambient air have shown elevated PM levels in areas with many wood stoves, particularly during wintertime when wood burning is common. Due to the size distribution of wood smoke particles essentially all will be contained in the PM{sub 2.5} fraction. It has been estimated that about 17,665 tonnes PM{sub 2.5} per year (2005) in Denmark come from residential wood combustion. Therefore, there is an increasing concern that adverse human health effects might be associated with the increased exposure to residential wood smoke. This project has been set up in order to review the scientific literature concerning adverse health effects of pollutants associated with residential wood smoke with the main focus on particulate matter and to quantify and evaluate, if possible, the impact on human health of the increased exposure to particles in residential wood smoke. (au)

  6. Broad spectrum antibiotic compounds and use thereof

    Energy Technology Data Exchange (ETDEWEB)

    Koglin, Alexander; Strieker, Matthias

    2016-07-05

    The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.

  7. Instream wood in a steep headwater channel: geomorphic significance of large and small wood

    Science.gov (United States)

    Galia, Tomáš; Šilhán, Karel; Ruiz-Villanueva, Virginia; Tichavský, Radek

    2016-04-01

    Besides the well-known significance of large wood (LW), also small woody pieces (SW; here defined as pieces with dimensions at least 0.5 m length and 0.05 m diameter), can play an important role in steep narrow headwaters. We inventoried instream wood in the 0.4 km long Mazák headwater channel, Moravskoslezské Beskydy Mts, Czech Republic (2attached by bed sediments or other wood), % of influenced channel width by a wood, the geomorphic function of a wood (step, wood jam) and % of length of a wood in channel were assessed. The total number of inventoried instream wood was 90 LWs and 199 SWs. In addition, dendrogeomorphic dating of 36 LWs and 17 SWs was performed to obtain residence time of local instream wood and to provide some insights into its mobility. Practically all investigated pieces were European beeches (Fagus sylvatica L.); only two pieces were Norway spruces (Picea abies (L.) Karst.). First results showed an increase in the number of LWs in channel-reaches confined by the steepest adjacent hillslopes (especially at 0.15-0.20 km). Increasing downstream amount of SW most likely reflected transport processes in the stream, and the later deposition of SWs on the lowest channel gradients. Also LWs and SWs in the downstream channel-reaches were more decayed than wood presented in the upper reaches. The orientation of instream wood was connected with its length and stability, and LWs longer than 5 m were usually attached to adjacent hillslopes. Pieces longer than 2 m, which were unattached or were somehow stabilized in the channel bed, had often orientation of 0° or 337°. LWs were mostly unattached in the upstream channel-reaches, while often stabilized by adjacent hillslopes in the middle part. At 0.05-0.10 km, there were also many logs stabilized by bed sediments. By contrast, SWs were mostly unattached in the whole longitudinal profile. We observed higher % of influenced channel width by SWs than LWs. Also, SWs were usually entirely located in the

  8. Wood decay in desert riverine environments

    Science.gov (United States)

    Andersen, Douglas; Stricker, Craig A.; Nelson, S. Mark

    2016-01-01

    Floodplain forests and the woody debris they produce are major components of riverine ecosystems in many arid and semiarid regions (drylands). We monitored breakdown and nitrogen dynamics in wood and bark from a native riparian tree, Fremont cottonwood (Populus deltoides subsp. wislizeni), along four North American desert streams. We placed locally-obtained, fresh, coarse material [disks or cylinders (∼500–2000 cm3)] along two cold-desert and two warm-desert rivers in the Colorado River Basin. Material was placed in both floodplain and aquatic environments, and left in situ for up to 12 years. We tested the hypothesis that breakdown would be fastest in relatively warm and moist aerobic environments by comparing the time required for 50% loss of initial ash-free dry matter (T50) calculated using exponential decay models incorporating a lag term. In cold-desert sites (Green and Yampa rivers, Colorado), disks of wood with bark attached exposed for up to 12 years in locations rarely inundated lost mass at a slower rate (T50 = 34 yr) than in locations inundated during most spring floods (T50 = 12 yr). At the latter locations, bark alone loss mass at a rate initially similar to whole disks (T50 = 13 yr), but which subsequently slowed. In warm-desert sites monitored for 3 years, cylinders of wood with bark removed lost mass very slowly (T50 = 60 yr) at a location never inundated (Bill Williams River, Arizona), whereas decay rate varied among aquatic locations (T50 = 20 yr in Bill Williams River; T50 = 3 yr in Las Vegas Wash, an effluent-dominated stream warmed by treated wastewater inflows). Invertebrates had a minor role in wood breakdown except at in-stream locations in Las Vegas Wash. The presence and form of change in nitrogen content during exposure varied among riverine environments. Our results suggest woody debris breakdown in desert riverine ecosystems is primarily a microbial process with rates determined by landscape position

  9. Pyrolytic characteristics of burning residue of fire-retardant wood

    Institute of Scientific and Technical Information of China (English)

    ZHAO Guangjie; LUO Wensheng; Furuno T; REN Qiang; MA Erni

    2007-01-01

    In order to investigate the pyrolytic characteristics of the burning residue of fire-retardant wood,a multifunctional fire-resistance test oven aimed at simulating the course of a fire was used to burn fire-retardant wood and untreated wood.Samples at different distances from the combustion surface were obtained and a thennogravimetric analysis (TG) was applied to test the pyrolytic process of the burning residue in an atmosphere of nitrogen.The results showed that:1) there was little difference between fireretardant wood and its residue in the initial temperature of thermal degradation.The initial temperature of thermal degradation of the combustion layer in untreated wood was higher than that in the no burning wood sample;2) the temperature of the flame retardant in fire-retardant wood was 200℃ in the differential thermogravimetry (DTG).The peak belonging to the flame retardant tended to dissipate during the time of burning;3) for the burning residue of fire-retardant wood,the peak belonging to hemicellulose near 230℃ in the DTG disappeared and there was a gentle shoulder from 210 to 240℃;4) the temperature of the main peaks of the fireretardant wood and its burning residue in DTG was 100℃ lower than that of the untreated wood and its burning residue.The rate of weight loss also decreased sharply;5) the residual weight of fire-retardant wood at 600~C clearly increased compared with that of untreated wood.Residual weight of the burning residue increased markedly as the heating temperature increased when burning;6) there was a considerable difference with respect to the thermal degradation temperature of the no burning sample and the burning residue between fire-retardant wood and untreated wood.

  10. The effects of heat treatment on the physical properties of juvenile wood and mature wood of Eucalyptus grandis

    Directory of Open Access Journals (Sweden)

    Bekir Cihad Bal

    2012-11-01

    Full Text Available Heat treatment can be used to improve the physical properties and durability of wood. The results achieved by heat treatment can be affected significantly by various factors. Juvenile wood and mature wood from the same trunk have different properties, and the effects of heat treatment on their physical properties have not been well defined. Thus, a study to determine the differences in the physical properties of juvenile wood and mature wood of E. grandis after heat treatment was conducted. Samples of both types of wood were treated at temperatures of 120, 150, and 180 oC for durations of 4, 6, and 8 h. The results showed that the physical properties of juvenile and mature wood, e.g., swelling, moisture content, and fiber saturation point, did not decrease to the same extent. Mass loss of mature wood was higher than that of juvenile wood. Generally, percentage decreases of volumetric swelling, moisture content, and fiber saturation point of juvenile wood were more affected than those of mature wood.

  11. Simulated wood budgets in two mountain streams

    Science.gov (United States)

    Hassan, Marwan A.; Bird, Stephen; Reid, David; Hogan, Daniel

    2016-04-01

    Large wood (LW) recruitment, transport, and storage were evaluated over a century in Gregory and Riley creeks (Haida Gwaii, British Columbia) by modeling a reach-scale LW budget using two frameworks for output: LW loss through decay and downstream transport, and loss through depletion. At reach and at watershed scales, mass movement and bank erosion dominated inputs, and fluvial transport was an important flux term in several reaches. Large wood recruitment by mortality was relatively minor in comparison. Large proportions of the in-channel LW were stored in jams with a mean age of 40-50 years. Overall, both modeling approaches yielded reasonable stored LW predictions in the study creeks, with the omission/inclusion of transport responsible for the largest differences between models. Modeled storage generally was within 30% of that measured in the field, and our results illustrate the large temporal variation in storage resulting from episodic inputs of LW from hillslopes.

  12. Properties of blue-stained wood

    Directory of Open Access Journals (Sweden)

    Miha Humar

    2008-07-01

    Full Text Available Discoloration of wood is frequently caused by blue-stain fungi. Among them Aureobasidium pullulans and Sclerophoma pithyophila are reported as the most important staining organism. In previous researches, it was generally considered that blue-stain fungi do not influence mechanical properties. However, there were some opposite results published as well. In order to elucidate this issue, specimens made of Scots pine (Pinus sylvestris sapwood were exposed to two blue stain fungi A. pullulans and S. pithyophila for periods between two and eight weeks. FTIR, weight, colour and non-destructive modulus of elasticity measurements were performed before and after exposure. The results showed that blue stain fungi, besides considerable discoloration, do not cause any significant damage to wood. Surprisingly the non-destructive MoE analysis showed that modulus of elasticity even slightly increase after fungal exposure.

  13. Remarks on the Woods-Saxon Potential

    CERN Document Server

    Capak, M

    2016-01-01

    More recently, comprehensive application results of approximate analytical solutions of the Woods-Saxon potential in closed form for the 5-dimensional Bohr Hamiltonian have been appeared [14] and its comparison to the data for many different nuclei has clearly revealed the domains for the sucsess and failure in case of using such potential forms to analyse the data concerning with the nuclear structure of deformed nuclei within the frame of the collective model. Gaining confidence from this work, exact solvability of the Woods-Saxon type potentials in lower dimensions for the bound states having zero angular momentum is carefully reviewed to finalize an ongoing discussion in the related literature and clearly shown that such kind of potentials have no analytical solutions even for l=0 case.

  14. Economic analysis of wood energy valorization

    International Nuclear Information System (INIS)

    Companies linked to the lumber activities began to concern about the valorization of their industrial residues: either by creating new products or by utilizing them for energy generation. At the same time, companies from other sectors began investing in reforestations dedicated to energy generation (mainly eucalyptus), induced by the possibility of obtaining tax incentives and by the need of assuring their own provisions of wood, thus minimizing this raw-material, as well as its sensibility to the variation of its price in the market. However almost nothing have been researched, either about the economical feasibility of energetic valorization of the lumber in the form of industrial residues or as wood supplied by reforestation dedicated to energy generation. This dissertation propose to examine those cases analysing the concerned costs and their economical feasibility. (author). 20 refs., 19 figs., 32 tabs

  15. Wood-framed houses for earthquake zones

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg

    Wood-framed houses with a sheathing are suitable for use in earthquake zones. The Direction describes a method of determining the earthquake forces in a house and shows how these forces can be resisted by diaphragm action in the walls, floors, and roof, of the house. An appendix explains how to d...... to design the wall, roof, and floor panels. The Direction is intended for design engineers and architects.......Wood-framed houses with a sheathing are suitable for use in earthquake zones. The Direction describes a method of determining the earthquake forces in a house and shows how these forces can be resisted by diaphragm action in the walls, floors, and roof, of the house. An appendix explains how...

  16. ELASTIC CHARACTERIZATION OF Eucalyptus citriodora WOOD

    Directory of Open Access Journals (Sweden)

    Adriano Wagner Ballarin

    2003-01-01

    Full Text Available This paper contributed to the elastic characterization of Eucalyptus citriodora grown inBrazil, considering an orthotropic model and evaluating its most important elastic constants.Considering this as a reference work to establish basic elastic ratios — several important elasticconstants of Brazilian woods were not determined yet - the experimental set-up utilized one tree of 65years old from plantations of “Horto Florestal Navarro de Andrade”, at Rio Claro-SP, Brazil. All theexperimental procedures attended NBR 7190/97 – Brazilian Code for wooden structures –withconventional tension and compression tests. Results showed statistical identity between compressionand tension modulus of elasticity. The relation observed between longitudinal and radial modulus ofelasticity was 10 (EL/ER ≈ 10 and same relation, considering shear modulus (modulus of rigidity was20 (EL/GLR ≈ 20. These results, associated with Poisson’s ratios herein determined, allow theoreticalmodeling of wood mechanical behavior in structures.

  17. Solid Wood Products from Eucalypts Plantations

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    To improve and diversify the use of tropical plantation timbers in Southern China, with support from International Tropical Timber Organizations (ITTO), a research project was started in 2002 focusing on development of processing and manufacturing technologies to promote production of value-added wood products from eucalypts plantations. This project will also facilitate the formulation of forest management strategy in China to supplement the diminishing supply of timber from the natural forests. The sp...

  18. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-31

    There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

  19. Natural Protection of Wood with Antagonism Fungi

    Directory of Open Access Journals (Sweden)

    Alba ZAREMSKI

    2011-03-01

    Full Text Available Biological environments contain a certain number of microbial populations which, within a givenecological niche, display various relations ranging from symbiosis to parasitism. Researchers have beeninterested in these types of relations for around fifty years, especially in one very particular type ofrelationship: the antagonism exerted between individuals of the same microbial population.Today, the role played by biological agents, bringing into play inhibitive or destructive antibioticsubstances, reveals a certain potential for their use in controlling microorganisms associated with suchdegradation processes.The work undertaken by HydroQuébec and CIRAD involved two types of experiment: 1 in Petri dishes toassess and characterize the antagonistic capacity of Trichoderma against white rot and brown rot fungi; 2on pieces taken from untreated poles in order to study confrontation between the basidiomycete and theantagonistic strain in wood.This study investigated the antagonism of three ascomycetes of the genus Trichoderma against two whiterot basidiomycetes, Pycnoporus sanguineus and Coriolus versicolor, and two brown rot basidiomycetes,Antrodia sp. and Coniophora puteana, through direct confrontation in Petri dishes and in the wood ofHydroQuébec poles.The results obtained seemed to complete each other coherently. They revealed that the Trichodermagroup of fungi was not aggressive to wood and the results obtained after direct confrontation in Petri disheswere confirmed in wood.By directly exposing the different basidiomycetes and antagonists to each other in Petri dishes, two bytwo, we effectively revealed an antagonism effect for a large majority of the pairs. However, there wassubstantial variability in reactions from one pair to the next.

  20. Product development in the wood industry

    OpenAIRE

    Stendahl, Matti

    2009-01-01

    It is common advice from strategy consultants that companies in the wood industry should increase their rate of innovation in order to survive global competition. Neither consultants nor academics, however, provide much advice on how this is to be achieved. For example, what resources are crucial for product innovation to take place and are current organizational structures suitable for development work? In this study, the product development processes of companies in this industry were exami...

  1. Willow wood production on radionuclide polluted areas

    Directory of Open Access Journals (Sweden)

    Rodkin Oleg I.

    2010-01-01

    Full Text Available ABSTRACT: One of the key environmental problems in Belarus is effective use of agricultural lands contaminated by radionuclide due to the Chernobyl disaster. The alternative method to traditional agricultural crops is fast growing willow cultivation. It is possible to use biomass of willow as renewable energy source. The goal of our investigation was the estimation of environmental aspects of willow wood production on polluted areas. The field study experiments (2007-2010 were conducted at Krichev district of Mogilev region in eastern Belarus. This region characterized by high level of Cs-137 contamination as well as high level of heavy metals pollution. In the first stage of experiments, the concentration of cesium-137 in different parts of willow biomass had been measured and transfer factor calculated. The measuring had been done for leaves, roots, and wood. To control cesium-137 accumulation in willow biomass we apply different types (nitrogen N, phosphorus P and potassium K and dose of fertilizer. The experiments show that potassium mineral fertilizer is the key factor for radionuclide accumulation control. The optimal dose of potassium is 90 kg per hectare. On the base of experimental results the model of cesium-137 accumulation in the wood for a 21 year has been developed. In accordance with calculation to the end of willow cultivation (21 year concentration of cesium-137 in wood will not be higher than permitted even with the level of cesium-137 contamination in the soil 1480 kBq/m2 (maximum 140 kqB/m2 with permitted level for firewood is 740 Bq/kg.. The concentration of cesium-137 in the roots increases gradually and get maximum in 21 year (3000 kqB/m2. Our results confirm that in the sum about 0.8 million hectares of radionuclide polluted arable lands partly excluded from agricultural practice in Belarus could be used for willow biomass production.

  2. ELASTIC CHARACTERIZATION OF Eucalyptus citriodora WOOD

    OpenAIRE

    Adriano Wagner Ballarin; Marcelo Nogueira

    2003-01-01

    This paper contributed to the elastic characterization of Eucalyptus citriodora grown inBrazil, considering an orthotropic model and evaluating its most important elastic constants.Considering this as a reference work to establish basic elastic ratios — several important elasticconstants of Brazilian woods were not determined yet - the experimental set-up utilized one tree of 65years old from plantations of “Horto Florestal Navarro de Andrade”, at Rio Claro-SP, Brazil. All theexperimental pro...

  3. Radioactivity of wood ash; Puun tuhkan radioaktiivisuus

    Energy Technology Data Exchange (ETDEWEB)

    Rantavaara, A.; Moring, M

    2000-01-01

    STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg{sup -1}, in decreasing order: {sup 137}Cs, {sup 40}K, {sup 90}Sr, {sup 210}Pb,{sup 226}Ra, {sup 232}Th, {sup 134}Cs, {sup 235}U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and {sup 210}Pb was hardly detectable. The NH{sub 4}Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

  4. Enzymatic hydrolysis of biomass from wood

    OpenAIRE

    Álvarez, Consolación; Reyes‐Sosa, Francisco Manuel; Díez, Bruno

    2016-01-01

    Summary Current research and development in cellulosic ethanol production has been focused mainly on agricultural residues and dedicated energy crops such as corn stover and switchgrass; however, woody biomass remains a very important feedstock for ethanol production. The precise composition of hemicellulose in the wood is strongly dependent on the plant species, therefore different types of enzymes are needed based on hemicellulose complexity and type of pretreatment. In general, hardwood sp...

  5. Health evaluation of volatile organic compound (VOC) emissions from wood and wood-based materials.

    Science.gov (United States)

    Jensen, L K; Larsen, A; Mølhave, L; Hansen, M K; Knudsen, B

    2001-01-01

    In this study, the authors describe a method for evaluation of material emissions. The study was based on chemical analysis of emissions from 23 materials representing solid wood and wood-based materials commonly used in furniture, interior furnishings, and building products in Denmark in the 1990s. The authors used the emission chamber testing method to examine the selected materials with a qualitative screening and quantitative determination of volatile organic compounds. The authors evaluated the toxicological effects of all substances identified with chamber testing. Lowest concentration of interest and standard room concentrations were assessed, and the authors calculated an S-value for each wood and wood-based material. The authors identified 144 different chemical substances with the screening analyses, and a total of 84 individual substances were quantified with chamber measurements. The irritative effects dominated at low exposure levels; therefore, the lowest concentration of interest and the S-value were based predominantly on these effects. The S-values were very low for solid ash, oak, and beech. For solid spruce and pine, the determining substances for size of the S-value were delta3-carene, alpha-pinene, and limonene. For the surface-treated wood materials, the S-value reflected the emitted substances from the surface treatment. PMID:11777023

  6. BIOENERGIA - Focus on wood in bioenergy research

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, D. [Jyvaeskylae Science Park, Jyvaeskylae (Finland)

    1996-12-31

    The most important area of research on wood fuel production is the development of various methods, machines and systems connected to this area, in order to produce economically competitive fuels. The integrated harvesting methods, which supply both raw material to wood products industry and wood fuel for energy production, have been chosen the main research area because they seem to be most promising. The growing amount of small-sized trees ant the need of their first thinnings have created a demand for new harvesting methods. At the moment the economical aspects restrict the harvesting of the first thinning trees either for industrial use or energy production. Research on peat production focuses on the complete use of a bog and on the development of peat production methods and machines. Development work in this area aims at decreasing production costs and also at reducing the drainage water and other elements in environmental load around the peat production sites. The use of bioenergy research will be focused on the small-scale (<20 MW{sub th},) applications. In the long term, the increase of bioenergy in heating of small houses and farms and buildings, as well as in the production of heat and power has been estimated. Research into the conversion of biomass is concentrated on the production of biomass-based liquid fuels

  7. FINITE ELEMENT ANALYSIS OF WOOD ADHESIVE JOINTS

    Directory of Open Access Journals (Sweden)

    Thomas GEREKE

    2016-03-01

    Full Text Available Engineered wood products such as glulam or cross-laminated timber are widely established in the construction industry. Their structural behaviour and reliability clearly bases on the adhesive bonding. In order to understand and improve the performance of glued wood members a finite element modelling of standard single lap shear samples was carried out. A three-dimensional model of a longitudinal tensile-shear specimen with quasi-centric load application was developed. The main influences of wood and adhesive parameters on structural performance were identified. Therefore, variations of the elasticity, the annual ring angle, fibre angle, and the interface zone and their effect on the occurring stresses in the adhesive bond line were investigated numerically. The adhesive bond line is most significantly sensitive to the Young´s modulus of the adhesive itself. A variation of the fibre angle of the glued members in the standard test is an essential criterion and to be considered when preparing lap shear specimens. A model with representation of early- and latewood gives a more detailed insight into wooden adhesive joints.

  8. Impregnation mode in wood plastic composite

    Science.gov (United States)

    Mozaffar Husain, M.; Khan, Mubarak A.; Azam Ali, M.; Idriss Ali, K. M.; Mustafa, A. I.

    1996-12-01

    Bulk monomer MMA was impregnated into simul, a fuel wood of Bangladesh, under vacuum and under normal temperature and pressure conditions in order to compare the mode of impregnation and its effect on various characteristic parameters of wood plastic composites. Methanol (MeOH) was used as the swelling solvent with methylmethacrylate (MMA) at MMA: MeOH = 70:30, v/v. Impregnation of the bulk monomer was very high under vacuum compared to that at normal condition; but the difference of grafting of MMA to the wood cellulose under these two impregnating conditions was much lower as compared to that of the uptakes of impregnating solution MMA + MeOH under these two modes of impregnation. Incorporation of additives to MMA + MeOH has substantially enhanced grafting, tensile strength, bending strength and compression strength of thcomposite of such an extent that there is virtually very little difference between vacuum impregnation and normal impregnation. Considering the available data it is suggested that the impregnation under normal condition is preferable beacuse different substrates of various sizes and shapes can be suitably impregnated under normal condition while vacuum impregnation has several limitations in this respect.

  9. Performance Simulation of Solid Wood Chairs

    Directory of Open Access Journals (Sweden)

    Silviu NEMEŞ

    2014-03-01

    Full Text Available Chairs made of solid wood belong to a category which requires special attention due to its frequent structural stressing. This study proposes the identification through load simulation of those structural elements, which can potentially become vulnerable. In this way measures can be taken during the design process to avoid eventual drawbacks and appropriate solutions can be found. The chair types that were the subject of this analysis have a simple construction, being commonly used in various human activities, but also the sitting ergonomics were kept in mind. When determining their dimensions, standards, studies and existing research were followed. The chair types were chosen as follows: a chair without stretchers, one with lateral stretchers and a lounge chair. The wood species for which the study was made is Fraxinus excelsior – ash wood, which shows average mechanical performance when compared to other hardwoods preferred by chair manufacturers. Its properties were used for a further analysis. Identifying the areas of the chair structure which are stressed by the human body was necessary in order to simulate real-life conditions. The finite element method was used, with a dedicated software. The interpretation of results is able to prove the quality of the design process. The proposed methodology may be applicable also for more complex chair structures.

  10. Weathering of copper-amine treated wood

    International Nuclear Information System (INIS)

    In this study, the effect of ultraviolet light (UV) irradiation and water spray on color, contact angle and surface chemistry of treated wood was studied. Southern pine sapwood (Pinus Elliottii.Engelm.) treated with copper ethanolamine (Cu-MEA) was subjected to artificially accelerated weathering with a QUV Weathering Tester. The compositional changes and the surface properties of the weathered samples were characterized by Fourier transform infrared (FTIR) spectroscopy, color and contact angle measurements. FTIR indicated that MEA treatment was not found to slow down wood weathering. FTIR spectrum of MEA-treated sample was similar to that of the untreated SP. However, the Cu-MEA treatment retarded the surface lignin degradation during weathering. The main changes in FTIR spectrum of Cu-MEA treatment took place at 915, 1510, and 1595 cm-1. The intensity of the bands at 1510 and 1595 cm-1 increased with the Cu-MEA treatment. Both untreated and MEA-treated exhibited higher ΔE than the Cu-MEA treated samples, indicating that MEA treatment did not retard color changes. However, ΔE decreased with increasing copper concentration, suggesting a positive contribution of Cu-EA to wood color stability. The contact angle of untreated and MEA-treated samples changed rapidly, and dropped from 75 ± 5o to 0o after artificial weathering up to 600 h. Treatment with Cu-MEA slowed down the decreasing in contact angle. As the copper concentration increases, the rate of change in contact angle decreases.

  11. Thermophotovoltaics, wood powder and fuel quality

    Energy Technology Data Exchange (ETDEWEB)

    Marks, J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Operational Efficiency; Broman, L.; Jarefors, K. [Solar Energy Research Center, Borlaenge (Sweden)

    1998-06-01

    PV cells can be used for electricity production based on other heat sources than the sun. If the temperature of the source is around 1500 K it is possible to get reasonably high conversion efficiency from heat radiation to electricity. This is due to recent advances in low-bandgap PV cells and selectively emitting fibrous emissive burners. There are some different biomass fuels capable of producing this temperature in the flame, especially gas and liquid fuels of different kinds. Wood powder is the only solid wood fuel with a sufficiently stable quality and properties for this high temperature combustion. A joint project between SERC, SLU and National Renewable Energy Laboratory NREL in Golden, Colorado, USA aims at building a wood powder fuelled thermophotovoltaic (TPV) generator for cogeneration of heat and electricity. A stable flame temperature of 1500 K has been achieved in a prototype pilot-scale burner that includes feeder and combustion chamber. Furthermore, a setup for measuring TPV cell efficiency for a wide region of black body emitter temperatures and cell irradiation has been constructed and several 0.6 eV GaInAs TPV cells have been investigated. A setup for testing the chain IR emitter - selectively reflecting filter - TPV cell has been designed. In order to limit the region of filter incident angles, which will make the filter act more efficiently, a special geometry of the internally reflecting tube that transmits the radiation is considered 23 refs, 4 figs

  12. THE MEASUREMENT AND DISTRIBUTION OF WOOD DUST

    Directory of Open Access Journals (Sweden)

    Andrea Rosario Proto

    2010-03-01

    Full Text Available In Italy, the woodworking industry presents many issues in terms of occupational health and safety. This study on exposure to wood dust could contribute to the realization of a prevention model in order to limit exposure to carcinogenic agents to the worker. The sampling methodology illustrated the analysis of dust emissions from the woodworking machinery in operation throughout the various processing cycles. The quantitative and qualitative assessment of exposure was performed using two different methodologies. The levels of wood dust were determined according to EN indications and sampling was conducted using IOM and Cyclon personal samplers. The qualitative research of wood dust was performed using an advanced laser air particle counter. This allowed the number of particles present to be counted in real time. The results obtained allowed for an accurate assessment of the quality of the dust emitted inside the workplace during the various processing phases. The study highlighted the distribution of air particles within the different size classes, the exact number of both thin and ultra-thin dusts, and confirmed the high concentration of thin dust particles which can be very harmful to humans.

  13. A cockroach for victory

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

    From 1 – 5 July, CERN had the pleasure of welcoming Céline, Fanny and Ophélia, the three winners of the special EIROforum prize donated by CERN in the EU Competition for Young Scientists 2012 (EUCYS). Between visits to the installations and meetings, the young French women had a memorable week.   Fanny Risbourg, Ophélia Bolmin and Céline Lay (from left to right), alongside their CERN guide, Marc Goulette. The rules of EUCYS, organised by the EU since 1989, require all candidates to have first won a scientific prize in their own country. That’s easily said… and done for these young scientists, who have won two! After coming first in France’s Engineering Science Olympiad in 2011, they then took home the top prize in the C. Génial competition the following year. “It all started three years ago, with our travaux personnels encadrés (supervised project),” Fanny explained...

  14. Functional lignocellulosic materials prepared by ATRP from a wood scaffold

    Science.gov (United States)

    Cabane, Etienne; Keplinger, Tobias; Künniger, Tina; Merk, Vivian; Burgert, Ingo

    2016-01-01

    Wood, a natural and abundant source of organic polymers, has been used as a scaffold to develop novel wood-polymer hybrid materials. Through a two-step surface-initiated Atom Transfer Radical Polymerization (ATRP), the porous wood structure can be effectively modified with polymer chains of various nature. In the present study, polystyrene and poly(N-isopropylacrylamide) were used. As shown with various characterization techniques including confocal Raman microscopy, FTIR, and SEM/EDX, the native wood ultrastructure and features are retained and the polymer chains can be introduced deep within the wood, i.e. inside the wood cell walls. The physical properties of the new materials have been studied, and results indicate that the insertion of polymer chains inside the wood cell wall alters the intrinsic properties of wood to yield a hybrid composite material with new functionalities. This approach to the functionalization of wood could lead to the fabrication of a new class of interesting functional materials and promote innovative utilizations of the renewable resource wood. PMID:27506369

  15. Theoretical computation and analysis of benefits of wood cutting power

    Institute of Scientific and Technical Information of China (English)

    MA Yan; YANG Chunmei; ZHAN Li

    2006-01-01

    This paper studies the problem of high energy waste in the course of the wood fiber processing in the wood-based panel industry.In the light of the energy economy principle,the cutting theory on the micron and long-slice wood fiber was put forward.In this paper,by means of analyzing the power waste in traditional processing,a series of analytical measures,such as,cytology,super precision work theory and fiber processing,and so on were utilized in the micron wood fiber formation process,and the cutting conception of the micron and long-slice wood fiber was put forward.Accordingly,the study of the micron and long-slice wood fiber was put into the microstructure study.This paper scientifically explains the reasons why the traditional wood fiber processing consumes more energy and the fiber quality low.In an example,the cutting power on the micron and long-slice wood fiber was calculated,which was compared with the traditional cutting power.The result showed that the energy waste by machining at micron is much lower than by heat grind and the high quality and long-slice wood fiber was gained.Thus,a revolutionary step was taken in the paper-making and wood-based panel industry of China.

  16. CHANGES IN THE CHEMICAL STRUCTURE OF THERMALLY TREATED WOOD

    Directory of Open Access Journals (Sweden)

    Birol Uner

    2010-07-01

    Full Text Available Changes in the chemical structure of hornbeam and uludag fir woods during thermal treatment were investigated at three temperatures (170, 190, and 210 oC and three durations (4, 8, and 12 hours. After thermal treatment, the extents of degradation in the chemical structure of the samples were determined, and the effects on the chemical composition of hornbeam wood and uludag fir wood were investigated. The data obtained were analyzed using variance analysis, and Tukey’s test was used to determine the changes in the chemical structure of uludag fir and hornbeam woods. The results showed that heating wood permanently changes several of its chemical structures and that the changes are mainly caused by thermal degradation of wood polymers. It was found that decreasing of the cellulose and holocelluloses ratio had a favorable effect on the interaction of the wood with moisture. According to the obtained results, hornbeam wood is affected more than uludag fir wood. For each wood, the maximum decreases of holocellulose and α-cellulose were found at 210oC for 12 hours, and the maximum increase of lignin occurred at the same treatment combination.

  17. Functional lignocellulosic materials prepared by ATRP from a wood scaffold

    Science.gov (United States)

    Cabane, Etienne; Keplinger, Tobias; Künniger, Tina; Merk, Vivian; Burgert, Ingo

    2016-08-01

    Wood, a natural and abundant source of organic polymers, has been used as a scaffold to develop novel wood-polymer hybrid materials. Through a two-step surface-initiated Atom Transfer Radical Polymerization (ATRP), the porous wood structure can be effectively modified with polymer chains of various nature. In the present study, polystyrene and poly(N-isopropylacrylamide) were used. As shown with various characterization techniques including confocal Raman microscopy, FTIR, and SEM/EDX, the native wood ultrastructure and features are retained and the polymer chains can be introduced deep within the wood, i.e. inside the wood cell walls. The physical properties of the new materials have been studied, and results indicate that the insertion of polymer chains inside the wood cell wall alters the intrinsic properties of wood to yield a hybrid composite material with new functionalities. This approach to the functionalization of wood could lead to the fabrication of a new class of interesting functional materials and promote innovative utilizations of the renewable resource wood.

  18. Against a Broad Definition of "Empathy"

    Directory of Open Access Journals (Sweden)

    Sarah Songhorian

    2015-04-01

    Full Text Available In this paper I will try to provide some arguments against a broad definition of “empathy”. Firstly, I will deal with attempts to define empathy as an umbrella concept. Then, I will try to point out the four main elements which contribute to the confusion that researchers in both the social and political as well as the scientific and philosophical domains face when dealing with empathy. In order to resolve this confusion, I suggest applying David Marr’s distinction to the field of empathy. Instead of providing an umbrella definition for empathy, which tries to account for all the data coming from different disciplines, I believe understanding that there are different levels of explanations and that different disciplines can contribute to each of them will provide a more detailed and less confused definition of empathy.

  19. Broad-band acoustic hyperbolic metamaterial

    CERN Document Server

    Shen, Chen; Sui, Ni; Wang, Wenqi; Cummer, Steven A; Jing, Yun

    2015-01-01

    Acoustic metamaterials (AMMs) are engineered materials, made from subwavelength structures, that exhibit useful or unusual constitutive properties. There has been intense research interest in AMMs since its first realization in 2000 by Liu et al. A number of functionalities and applications have been proposed and achieved using AMMs. Hyperbolic metamaterials are one of the most important types of metamaterials due to their extreme anisotropy and numerous possible applications, including negative refraction, backward waves, spatial filtering, and subwavelength imaging. Although the importance of acoustic hyperbolic metamaterials (AHMMs) as a tool for achieving full control of acoustic waves is substantial, the realization of a broad-band and truly hyperbolic AMM has not been reported so far. Here, we demonstrate the design and experimental characterization of a broadband AHMM that operates between 1.0 kHz and 2.5 kHz.

  20. A broad view of model validation

    International Nuclear Information System (INIS)

    The safety assessment of a nuclear waste repository requires the use of models. Such models need to be validated to ensure, as much as possible, that they are a good representation of the actual processes occurring in the real system. In this paper we attempt to take a broad view by reviewing step by step the modeling process and bringing out the need to validating every step of this process. This model validation includes not only comparison of modeling results with data from selected experiments, but also evaluation of procedures for the construction of conceptual models and calculational models as well as methodologies for studying data and parameter correlation. The need for advancing basic scientific knowledge in related fields, for multiple assessment groups, and for presenting our modeling efforts in open literature to public scrutiny is also emphasized. 16 refs

  1. Magnetohydrodynamic stability of broad line region clouds

    CERN Document Server

    Krause, Martin; Burkert, Andreas

    2012-01-01

    Hydrodynamic stability has been a longstanding issue for the cloud model of the broad line region in active galactic nuclei. We argue that the clouds may be gravitationally bound to the supermassive black hole. If true, stabilisation by thermal pressure alone becomes even more difficult. We further argue that if magnetic fields should be present in such clouds at a level that could affect the stability properties, they need to be strong enough to compete with the radiation pressure on the cloud. This would imply magnetic field values of a few Gauss for a sample of Active Galactic Nuclei we draw from the literature. We then investigate the effect of several magnetic configurations on cloud stability in axi-symmetric magnetohydrodynamic simulations. For a purely azimuthal magnetic field which provides the dominant pressure support, the cloud first gets compressed by the opposing radiative and gravitational forces. The pressure inside the cloud then increases, and it expands vertically. Kelvin-Helmholtz and colu...

  2. Impact of Wood Species, Dimensions and Drying Temperature on Sorption Behaviour of Wood

    Directory of Open Access Journals (Sweden)

    Darius Albrektas

    2015-04-01

    Full Text Available This research paper examines the interdependence between wood sorption properties and its dimensions, species and drying temperature. The research was carried out on specimens of six species of wood (oak, ash, aspen, birch, spruce and pine which had different dimensions and were dried at temperatures ranging between 30 and 90 °C. Subsequently specimens underwent the moistening and air drying process, and the following parameters were recorded: moistening and drying rate, moisture content distribution, steady moisture content and sorption hysteresis. It was established that sorption hysteresis was most affected by the cross section dimensions of the specimen. It was determined that, when the thickness of wood specimens increases from 7 to 30 mm, sorption hysteresis grows up to 8 times. The steady moisture content depends on the density, measurements and drying temperature of the specimen.

  3. 引入Logistic混沌映射的连续蟑螂算法应用于函数优化问题%Continuous Cockroach Swarm Optimization with Logistic Chaotic Map for Solving Function Optimization Problems

    Institute of Scientific and Technical Information of China (English)

    程乐; 杨晔; 钱兆楼; 韩锐; 潘永安

    2011-01-01

    For solving function optimization problems ,a new continuous cockroach swarm optimization(CCSO)is put forward in this paper. Some biological characteristics of cockroach has been simulated ,such as gregarious colony, non-fixing nest , disorderly craw-ling path and so on. The argorithm have truck throwing food in solution space. The cockroaches could crawl to these food and search for optimal solutions. Logistic chaotic map is used in nest distribution and throwing food. The experimental results show that CCSO is surpior to API and PPBO in Solving Precision,convergent rates and optimization rate.%通过模拟蟑螂的觅食行为,提出用于解决函数优化问题的连续蟑螂算法(continuous cockroach swarm optimization,CC-SO).算法模拟了蟑螂的群居、巢穴不固定、爬行轨迹杂乱无章等生物特性.通过食物车在解空间内抛洒食物,吸引蟑螂向食物爬行完成搜索.在巢穴分配和食物抛洒环节引入了Logistic混沌映射,增强了巢穴和食物在解空间内分布的随机性和遍历性.仿真实验显示,与API和PPBO算法相比,CCSO算法在求解精度、收敛速度、寻优率等方面均提高显著.

  4. State-of-the-art of the European regulation on wood wastes and wood ashes valorization. Synthesis

    International Nuclear Information System (INIS)

    This study has the objective of comparing the regulations of 10 European countries with that of France, in relation to the classification and recycling of wood waste, in particular lightly treated wood, as well as recycling of wood ash. The first part relating to wood waste presents a detailed analysis by country as well as a summary, on the one hand, of the various sectors for recycling waste wood and, on the other, the emission limits for their energy recovery. Generally, there is a distinction between waste covered by the incineration directive, and the others, without any particular category for lightly treated wood. However, recommendations emerge from this that are based essentially on the regulations or guidelines observed in Germany, Austria and the United Kingdom. The second part relating to wood ash also a presents a detailed analysis by country as well as a summary of the various sectors of recycling and limit values for spreading. Ash is generally considered as waste, and is recycled on a case-by case basis. Only Germany and Austria have clearly integrated wood ash in their regulatory framework. Overall this study shows the need for uniform regulation at European level, establishing environment requirements for recycling wood waste and wood ash, in order to encourage development of the use of biomass

  5. An Analysis of the U.S. Wood Products Import Sector: Prospects for Tropical Wood Products Exporters

    Directory of Open Access Journals (Sweden)

    W.A.R.T.W. Bandara

    2012-10-01

    Full Text Available The U.S. has dramatically altered its wood product imports and exports during the past few years,and at present, it is the second largest wood product importer in the world. Hence, an understanding ofmarket structures, factors in selecting foreign suppliers, and the emphasis placed on environmentalissues/certification are critical to understand from the perspective of wood products importers in the U.S.This study provides an analysis of the U.S. wood products import sector with special emphasis on currentand future opportunities for tropical wood products exporters to the U.S. market.In this study, 158 wood products importers in the U.S. were surveyed using a mailingquestionnaire. The adjusted response rate was 40.6 percent. Results indicated that most of the respondentswere small to medium scale firms, but major importers of wood products. According to respondents,wood products to the U.S. mainly come from Brazil, Chile, and China. From the importers’ perspective,Brazilian wood products ranked first for its quality followed by wood products from Chile and Finland.Product quality, long term customer relationships, on-time delivery of orders, fair prices, and supplierreputation were the factors deemed important in selecting overseas suppliers. Majority of respondentswere importing certified wood products. FSC, SFI, and ISO 14000 were the mostly accepted certificationprograms. However, certification was not a major factor in foreign supplier selection criteria. Whenconsidered the U.S. wood products importers’ tendency to diversify their products and species imported,attractive opportunities exist for wood products suppliers from tropical countries.

  6. Method for improving separation of carbohydrates from wood pulping and wood or biomass hydrolysis liquors

    Science.gov (United States)

    Griffith, William Louis; Compere, Alicia Lucille; Leitten, Jr., Carl Frederick

    2010-04-20

    A method for separating carbohydrates from pulping liquors includes the steps of providing a wood pulping or wood or biomass hydrolysis pulping liquor having lignin therein, and mixing the liquor with an acid or a gas which forms an acid upon contact with water to initiate precipitation of carbohydrate to begin formation of a precipitate. During precipitation, at least one long chain carboxylated carbohydrate and at least one cationic polymer, such as a polyamine or polyimine are added, wherein the precipitate aggregates into larger precipitate structures. Carbohydrate gel precipitates are then selectively removed from the larger precipitate structures. The method process yields both a carbohydrate precipitate and a high purity lignin.

  7. Proceedings of the 8. biennial residual wood conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This conference highlighted practical strategies for managing and utilizing residual wood as a true industry resource. Examples of successful wood energy projects were presented along with the technology and products of more than 30 companies involved in the residual wood business. The topics of discussion ranged from biomass supplies, quality issues, and harvesting guidelines to emerging biomass technologies, project overviews, and financing. The presentations outlined the many opportunities that exist for the forest industry to produce energy from biostock, such as healthy and diseased trees, underbrush, sawdust, wood chips, wood pulp and black liquor. Increasing fuel and energy costs along with advances in technology are improving the economy of forest-based biorefineries. The presentations showed how the industry can gain revenue from residual wood, which is steadily becoming a more valuable resource for pellet production and energy generation The conference featured 20 presentations, of which 3 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  8. Biological durability of wood modified by citric acid

    Directory of Open Access Journals (Sweden)

    Bogoslav Šefc

    2008-07-01

    Full Text Available This paper presents the results of measurement of durability of beech wood (Fagus sylvatica modified by Citric Acid (CA against brown rot fungus Poria placenta according to EN 113. Modification was performedby impregnation with 7.0% CA and 6.5% sodium-hypophosphite (SHP water solution and 10-hour curing at 140 °C. The influence of thermal treatment on durability was also researched. Weight percentage gain (WPG caused by modification, moisture content (MC and mass loss of wood (dm after fungal nutrition were measured. WPG of modified beech wood was 6.1% and that of thermally treated wood was -0.3%. The results showed increased durability of modified wood to be 8.3 times greater than nonmodified, while thermal treatment did not give significant durability improvement. These results indicate modification by CA as a promising alternative, but further research on optimisation of modification parameters is needed to achieve improvement of wood properties.

  9. Effects of wood dust:Inflammation, Genotoxicity and Cancer

    DEFF Research Database (Denmark)

    Lange, Jette Bornholdt

    The present thesis focuses on the inflammatory, genotoxic and carcinogenic effects of exposure to different species of wood dust. The experimental work performed in this thesis consists of two parts. The first part of the study was carried out in an in vitro model with the human lung epithelial...... with incidence rates between of 0.3 to 1.4 per 100,000 for men and 0.1 to 0.8 per 100,000 for women in Europe, depending on country. However, cancer at this site is associated with occupational exposures including wood dust. Especially the adenocarcinoma subtype is strongly associated with exposure to wood dust...... primarily from hard woods. Non-malignant symptoms like allergy, asthma, rhinitis and chronic bronchitis have also been associated with occupational exposure to wood dust in epidemiological studies. In most epidemiological studies hardwoods (e.g. oak and beech wood dust) seems to have greater association...

  10. Acidity of selected industrial wood species in Serbia

    Directory of Open Access Journals (Sweden)

    Popović Mlađan

    2016-01-01

    Full Text Available The acidity of wood has an important role in many areas of wood applications. Hence, this paper presents a study on the acidity of beech, fir and poplar, as the representatives of the most industrially utilized wood species in Serbia. The contents of both the soluble and insoluble acids were determined through the extraction methods with cold distilled water and sodium acetate solution, respectively, followed by the titration with sodium hydroxide solution. The acidity strongly differs among the three wood species used in this research. The amount of insoluble acids was the highest in fir, almost twice as much than in poplar, and about 68 % higher than in fir wood species. Such differences also showed a strong correlation with the gel times of UF adhesive mixes with hot water extracts. [Projekat Ministarstva nauke Republike Srbije, br. TP 31041: Establishment of Wood Plantations Intended for Afforestation of Serbia

  11. Remarks on orthotropic elastic models applied to wood

    Directory of Open Access Journals (Sweden)

    Nilson Tadeu Mascia

    2006-09-01

    Full Text Available Wood is generally considered an anisotropic material. In terms of engineering elastic models, wood is usually treated as an orthotropic material. This paper presents an analysis of two principal anisotropic elastic models that are usually applied to wood. The first one, the linear orthotropic model, where the material axes L (Longitudinal, R( radial and T(tangential are coincident with the Cartesian axes (x, y, z, is more accepted as wood elastic model. The other one, the cylindrical orthotropic model is more adequate of the growth caracteristics of wood but more mathematically complex to be adopted in practical terms. Specifically due to its importance in wood elastic parameters, this paper deals with the fiber orientation influence in these models through adequate transformation of coordinates. As a final result, some examples of the linear model, which show the variation of elastic moduli, i.e., Young´s modulus and shear modulus, with fiber orientation are presented.

  12. Variation in the Growth Traits and Wood Properties of Chinese Fir from Six Provinces of Southern China

    Directory of Open Access Journals (Sweden)

    Hongjing Duan

    2016-08-01

    Full Text Available To determine the phenotypic variation in 700 ten-year grafted Chinese fir collected from six provinces in southern China, 10 phenotypic traits were investigated: tree height, diameter at breast height, bark thickness, volume of timber, heartwood ratio, density of wood, hygroscopicity, tracheid length, tracheid diameter, and ratio of tracheid length to tracheid diameter. Abundant phenotypic variation was found among the six populations; the phenotypic variation coefficients all exceeded 10%, and the largest was for volume of timber. Significant variation (p < 0.01 or 0.05 in traits was found among the populations, except for diameter at breast height, heartwood ratio, and tracheid diameter, while all traits differed significantly (p < 0.01 within populations. The high value of repeatability (broad-sense heritability suggested moderate genetic control of the traits. The 10 traits were strongly correlated within the entire population; strong positive correlations (p < 0.01 were observed between growth traits, and significant negative correlations (p < 0.01 or 0.05 were found between the density of wood and most other characteristics, except for heartwood ratio and ratio of tracheid length to tracheid diameter. Using diameter at breast height and density of wood as criteria, 98 relatively fast-growing genotypes with relatively high wood basic density were identified.

  13. A near infrared spectroscopic study of the structural modifications of lime (Tilia cordata Mill.) wood during hydro-thermal treatment

    Science.gov (United States)

    Popescu, Carmen-Mihaela; Popescu, Maria-Cristina

    2013-11-01

    The modifications and/or degradation of lime (Tillia cordata) wood components during wood heat treatment under low temperature at about 140 °C and 10% percentage of relative humidity were evaluated. The aim of this study was to obtain results by simple NIR coupled with second derivative, principal component analysis and two dimensional correlation spectroscopy in order to better understand how these techniques are able to evaluate structural differences resulted under hydro-thermal treatment of the wood over a period of 504 h. The NIR spectra of treated samples were compared with the reference one. Due to the broad bands in the NIR spectra, the assignment and modifications occurring during treatment is difficult, therefore the second derivative principal component analysis were applied. Principal component analysis by first two components was able to differentiate the samples series, PC1 being considered as the time axis, and PC2 as the axis representing the structural modification of wood components. 2D NIR correlation spectroscopy was able to estimate the sequential order of the groups variations under the hydro-thermal treatment time as external perturbation, indicating as first moment changes the OH and Csbnd O groups from carbohydrates and lignin, followed by Carsbnd H, Csbnd H and CH2 groups from lignin, cellulose and hemicelluloses.

  14. Protagonista lugubris , a cockroach species new to China and its contribution to the revision of genus Protagonista , with notes on the taxonomy of Archiblattinae ( Blattodea , Blattidae )

    OpenAIRE

    Wang, Chenchen; Wang, Zongqing; Che, Yanli

    2016-01-01

    Abstract The blattid genus Protagonista Shelford, 1908, which is tentatively assigned to the subfamily Archiblattinae (= Planeticinae ), is reported from China for the first time with illustrations and description of Protagonista lugubris Shelford, 1908. It is a wood-dwelling and potentially a wood-feeding species. The male and female genitalia of Protagonista are described and illustrated for the first time. The species Protagonista pertristis Hanitsch, 1923 is revived from the synonymy of P...

  15. The Fractal Nature of Wood Revealed by Drying

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experiment on wood drying at different temperatures was conducted to show the fractal nature of the pore space within wood. Cubic blocks made from ginkgo (Ginkgo biloba) and Chinese chestnut (Castanea mollissima) wood were used. Samples were dried in oven at the temperature of 20, 40, 60 and 100 ℃, respectively. All the drying procedures lasted four hours. The mass was weighed and the dimensions were measured immediately for each sample when every procedure of drying ended. The fractal dimensions of ...

  16. Pyrolysis of furniture wood waste: Decomposition and gases evolved

    OpenAIRE

    Moreno Caballero, Ana Isabel; Font Montesinos, Rafael

    2015-01-01

    The pyrolysis of furniture wood waste was studied due to its importance as a thermochemical conversion process, and also because it is a step in the combustion process. Furniture wood contains organic additives and inorganic elements (being noteworthy the high content of Ti). These additives cause changes in the thermal processes. A thermogravimetric analysis of the pyrolysis of furniture wood waste was carried out in a TGA apparatus using dynamic and dynamic + isothermal runs. The pyrolysis ...

  17. Anatomy of wood for bows of string instruments

    OpenAIRE

    Čufar, Katarina; Demšar, Blaž; Zupančič, Martin; Koch, Gerald; Oven, Primož

    2007-01-01

    Four specimens of wood originating from string instrument bows or from the material intended to be used for the repair of bows were obtained from the string instrument workshop "Atelje Demšar". Foreign wood traders supplied the specimens under their commercial names: (1) pernambouc, (2) horse flesh, (3) brasil, and (4) snakewood. Macroscopic and microscopic wood anatomical investigations were carried out in order to verify the nomenclature of the traded specimens. The microscopic identificati...

  18. The role of water in the behavior of wood

    OpenAIRE

    Derome, Dominique; Rafsanjani, Ahmad; Hering, Stefan; Dressler, Martin; Patera, Alessandra; Lanvermann, Christian; Sedighi-Gilani, Marjan; Wittel, Falk K; Niemz, Peter; Carmeliet, Jan

    2015-01-01

    Wood, due to its biological origin, has the capacity to interact with water. Sorption/desorption of moisture is accompanied with swelling/shrinkage and softening/hardening of its stiffness. The correct prediction of the behavior of wood components undergoing environmental loading requires that the moisture behavior and mechanical behavior of wood are considered in a coupled manner. We propose a comprehensive framework using a fully coupled poromechanical approach, where its multiscale impleme...

  19. Test evaluation of a laminated wood wind turbine blade concept

    Science.gov (United States)

    Faddoul, J. R.

    1981-01-01

    A series of tests conducted on a root end section of a laminated wood wind turbine blade are reported. The blade to hub transition of the wood blade uses steel studs cast into the wood D spar with a filled epoxy. Both individual studs and a full scale, short length, root section were tested. Results indicate that the bonded stud concept is more than adequate for both the 30 year life fatigue loads and for the high wind or hurricane gust loads.

  20. Flame retardancy of paulownia wood and its mechanism

    OpenAIRE

    Li, Peng; Oda, Juhachi

    2007-01-01

    Paulownia wood (Pauloumia tomentosa) is a special kind of wood material in that it has especially excellent flame retardancy. Using this property, it has been commonly used to make clothing wardrobes for a long time in Japan. In this research, the flame retardancy of paulownia wood has been verified by heating experiments and cone calorimeter testing. The structure and tissue of the material have been analyzed by scanning electron microscope and other methods. Moreover, the mechanism of the f...

  1. Studies of properties of rubber wood with impregnation of polymer

    Indian Academy of Sciences (India)

    Rashmi R Devi; T K Maji

    2002-11-01

    Impregnation of rubber wood has been carried out under different conditions by using styrene as grafting monomer and glycidyl methacrylate (GMA) as crosslinker. Properties such as dimensional stability, water absorption, hardness, tensile strength, flexural strength, etc of the impregnated wood have been checked and found to be improved by incorporation of GMA as the crosslinker with styrene. The polymer-impregnated wood has also been characterized by FTIR spectroscopy and DSC.

  2. Wood Biomass Sustainability under the Renewable Energy Directive

    OpenAIRE

    GORDEEVA, Yelena

    2014-01-01

    The article studies the role of wood biomass as a source of renewable energy in the EU and the potential sustainability risks associated with the rapid growth in the use of wood stimulated by the Renewable Energy Directive (RED). Secondly the article discusses the RED's sustainability criteria and their applicability to wood biomass. Thirdly, the article analyzes the current legal framework for forest management that is referred to by the European Commission as "enough to provide assurances f...

  3. Wood Use Trends in the Pallet and Container Industry

    OpenAIRE

    Bejune, Jeffery J.

    2001-01-01

    This study was undertaken to determine the use and quantities of new and recovered wood materials utilized by the United States pallet and container industry in 1999. Wood use trends were identified by comparing the results of this study with that of three previous studies (1992, 1993, and 1995) conducted by Virginia Tech and the United States Forest Service. Also, information was gathered on firm employment, plant operations, and production. A mail survey of 3,507 manufacturers of wood pa...

  4. New insights into carbon transport and incorporation to wood

    OpenAIRE

    Mahboubi, Amir

    2015-01-01

    Wood formation in trees requires carbon import from the photosynthetic tissues. In several tree species the majority of this carbon is derived from sucrose transported in the phloem. This thesis describes experimental work on the mechanism of radial sucrose transport from phloem to developing wood and subsequent incorporation of carbon into wood polymers. I investigated the role of active sucrose transport during secondary cell wall formation in hybrid aspen (Populus tremula x tremuloides...

  5. Systematic wood anatomy of the tribe Guettardeae (Rubiaceae)

    OpenAIRE

    Welle, ter, B.J.H.; Loureiro, A.A.; Lisboa, P.L.B.; Koek-Noorman, J.

    1983-01-01

    Systematic wood anatomy of the tribe Guettardeae (Rubiaceae). The wood anatomy of nearly all genera of the Guettardeae (Rubiaceae, Guettardoideae) has been examined, and in this respect the tribe is heterogeneous. Suggestions are made for a delimitation of the tribe. Guettarda, Bobea, Antirhea, Malanea and Chomelia Jacq. are sufficiently similar in their wood anatomical characters to warrant retention in the same tribe. Machaonia, Timonius and Dichilanthe are anomalous. Suggestions are given ...

  6. Plantation Forests for Sustainable Wood Supply and Development in China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    With the implementation of Natural Forests Protection Program, wood resource base in China is shifting from naturally grown forests to plantation forests. This paper reviews: 1) The evolution of Chinese decade-long reforestation program and its contribution to sustainable wood supply and development, and 2) impacts of "China's Natural Forest Protection Program and " Fast-Growing and High-Yield Plantation Program in China " on China's wood supply and sustainability. In addition, this paper highlights Chi...

  7. Energy wood procurement in connection with conventional wood procurement; Energiapuun hankinnan organisointi muun puunhankinnan yhteydessae - PUUT02

    Energy Technology Data Exchange (ETDEWEB)

    Maekinen, P. [The Finnish Forest Research Institute, Vantaa (Finland)

    2000-08-01

    The research consists of three sub-projects. The present role of forestry associations in purchase of wood fuels is studied in the sub-project no. one. The possibilities and willingness of them to increase their share in purchase of wood fuels is also studied. The roles of forest machine and forest service entrepreneurs in purchase of wood fuels are investigated in the sub-project number two. The effects of energy wood harvesting on the operation of forest machine entrepreneur will also be studied this sub-project. The requirements of customers for the suppliers of energy wood are studied in the sub-project no. three. All the data in these sub-projects will be collected using personal interviews. It appeared that the harvesting of energy wood had no effect on the degree of employment of forest machine entrepreneurs, and that the energy wood entrepreneurs did not differ from other entrepreneurs. The activity of forest machine entrepreneurs was estimated to grow in the harvesting of energy wood in the near future. Measuring and accrual basis practices seemed also to differ widely from each other. The technologies appeared also to be targets of continuous development, so the technologies were relatively impermanent. Harvesting of energy wood was not seen to play a significant role in increment of the employment and turnover. However, the effect of energy wood harvesting on the aggravation of industrial wood harvesting was estimated to be more significant. In the future the end-users of energy wood word like to have more competition in the markets. However, the suppliers were wanted to be fairly large, so that the reliability of deliveries could be guaranteed. The potential for increasing the utilization of wood fuels is high, but the competitiveness of peat was estimated to be high, and simultaneously it was estimated to be a threat to increment of the utilization of wood fuels. As the end users want to decrease the price of the wood fuels, the wood chipping companies

  8. Photoionisation modelling of the broad line region

    Science.gov (United States)

    King, Anthea

    2016-08-01

    Two of the most fundamental questions regarding the broad line region (BLR) are "what is its structure?" and "how is it moving?" Baldwin et al. (1995) showed that by summing over an ensemble of clouds at differing densities and distances from the ionising source we can easily and naturally produce a spectrum similar to what is observed for AGN. This approach is called the `locally optimally emitting clouds' (LOC) model. This approach can also explain the well-observed stratification of emission lines in the BLR (e.g. Clavel et al. 1991, Peterson et al. 1991, Kollatschny et al. 2001) and `breathing' of BLR with changes in the continuum luminosity (Netzer & Mor 1990, Peterson et al. 2014) and is therefore a generally accepted model of the BLR. However, LOC predictions require some assumptions to be made about the distribution of the clouds within the BLR. By comparing photoionization predictions, for a distribution of cloud properties, with observed spectra we can infer something about the structure of the BLR and distribution of clouds. I use existing reverberation mapping data to constrain the structure of the BLR by observing how individual line strengths and ratios of different lines change in high and low luminosity states. I will present my initial constraints and discuss the challenges associated with the method.

  9. Neutralization of low energy broad ion beam

    International Nuclear Information System (INIS)

    The paper is devoted to experimental and theoretical investigation of a low energy broad ion beam space charge and current compensation and ion-beam plasma (IBP), which would be created in transport space of the beam. The beam had cylindrical symmetry. The continuous uniform and hole tube like ion beams are used in the experiments. Different channels of electron appearing have been investigated for cases of neutralization due to secondary γ-electrons from the target and by electrons from glow cathode-neutralizer with metal or dielectric target. Results of neutralizing electrons energy distributions function measurements are presented as well as dependences of electron temperature and self-consisted plasma potential vs. beam parameters, ambient gas pressure, neutralizer parameters. Role of the thermoelectrons and dependence of IBP parameters on neutralizer area, location and potential are discussed. Significant role in neutralization of spatial collisional processes has been revealed even in neutralization by thermocathode. On the base of the experimental results self-consistent theoretical model have been developed, which describes the behavior of intense ion beam passing through the neutral gas at low pressure within conductive walls. The collisionless approach is used which means absence of collisional relaxation of the beam. This theory is used to derive the plasma potential and electron temperature within the beam

  10. Preliminary studies of Brazilian wood using different radioisotopic sources

    International Nuclear Information System (INIS)

    Due to availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instrument; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere with the growth of trees. This behavior explains why average physical-chemical properties are important when wood is studied. The majority of researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties of wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: 'freijo', 'jequetiba', 'muiracatiara' and 'ipe'. For wood density determination by non-conventional method, Am-241, Ba-133 and Cs-137 radioisotopic sources; a NaI scintillation detector and a counter were used. The results demonstrated this technique to be quick and accurate. By considering the nuclear parameters obtained as half value layers and linear absorption coefficients, Cs-137 radioisotopic source demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. (author)

  11. Electrodialytic remediation of CCA treated waste wood in pilot scale

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Christensen, Iben Vernegren; Ottosen, Lisbeth M.;

    2005-01-01

    When CCA (Chromated Copper Arsenate) treated wood is removed from service and turns into waste, the contents of Cu, Cr and As is still high due to the strong fixation of CCA in the wood. This high content of toxic compounds presents a disposal challenge. Incineration of CCA treated waste wood......-ples of electrodialysis. It has previously been shown that it is possible to remove Cu, Cr and As from CCA treated wood using electrodialytic remediation in laboratory scale (Ribeiro et al., 2000; Kristensen et al., 2003), but until now, the method had not been studied in larger scale. The pilot scale plant used...

  12. Biological Durability of Oil Heat Treated Alder Wood

    Directory of Open Access Journals (Sweden)

    Robert Lacić

    2014-06-01

    Full Text Available The article presents preliminary results of the biological durability of oil heat treated (OHT alder wood (Alnus glutinosa against pure cultures of rot fungi (Postia placenta and Trametes versicolor in lab conditions. The modification was performed by heating of specimens immersed in soya oil. There were four heating regimes of different duration (6 and 10 hours at final temperature of 180 and 200 ºC. The increase in mass (MI caused by modification and mass loss of wood caused by fungal decay (ML were determined. In addition, the natural durability of alder wood was determined and compared to the natural durability of beech wood as the reference wood species. After modification of alder wood at 200 °C, MI was lower than after treatment at 180 °C. MI was also lower after 10 hours of treatment than after 6 hours of treatment. The results showed significantly increased biological durability of modified alder wood against both tested fungi. The effect of OHT on increasing the biological durability of alder wood was higher against the fungus P. placenta. It seems that the fungus T. versicolor favours the remained oil after modification causing higher mass loss. The results showed that alder wood, thermally modified in soya oil by testing regimens, is not suitable for applications in use classes 3-5.

  13. A study of New Zealand wood workers: exposure to wood dust, respiratory symptoms, and suspected cases of occupational asthma.

    Science.gov (United States)

    Norrish, A E; Beasley, R; Hodgkinson, E J; Pearce, N

    1992-05-27

    A randomly selected group of 50 New Zealand wood workers was studied. The level of airborne wood dust to which they were exposed ranged from 1.0-24.5 mg/m3. The wood workers reported experiencing higher rates of both lower and upper respiratory tract symptoms than a control group of office workers. Inhaled wood dust, in particular from rimu (Dacrydium cupressinum), was frequently cited by workers as being associated with respiratory tract symptoms. The wood workers' responses to the respiratory symptom questionnaire, and serial recordings of peak expiratory flow rate were used to screen the group for suspected cases of occupational asthma. Five cases fulfilled the study's criteria for suspected occupational asthma. In four of these, further evidence was found to support this diagnosis. We conclude that exposure to wood dust may cause occupational asthma in the woodworking industry in New Zealand.

  14. Discovery and Significance of the Grain of Wild Rice in Ancient-Woods Layer in Zhujiajian Island of Zhejiang Province, China

    Institute of Scientific and Technical Information of China (English)

    SHENXian-sheng; LIShu-mei; YANGJie-pin; SUNHao

    2004-01-01

    A large number of plant remains were discovered in the ancient-woods layer of Zhujiajian Island, Zhejiang Province.There were some thick trunks, complete laminas, fruit, seeds and so on. According to radiocarbon tests conducted for plant remains, the ancient-woods layer has been dated back to about 8750 - 6200 years, and the vegetation was a subtropical evergreen and deciduous broad-leaved mixed forests on the island in the past. In the middle of the ancient-woods layer, two grains of wild rice were explored accidentally, which are Oryza rufipogon, along with the fruit and seeds of some water plants, such as Ceratophyllum dcmcrsum, C.oryzetoum, Euryale fetox, Trapa incisa var. quadricaudata , Scirpus yagara and so on. There might be marshy soil and a pond in ancient forest vegetation from where the grains of wild rice and hydrophytic fruit were found. It is of tremendous importance to study the origin of wild rice in China.

  15. Discovery and Significance of the Grain of Wild Rice in Ancient-Woods Layer in Zhujiajian Island of Zhejiang Province, China

    Institute of Scientific and Technical Information of China (English)

    SHEN Xian-sheng; LI Shu-mei; YANG Jie-pin; SUN Hao

    2004-01-01

    A large number of plant remains were discovered in the ancient-woods layer of Zhujiajian Island, Zhejiang Province.There were some thick trunks, complete laminas, fruit, seeds and so on. According to radiocarbon tests conducted for plant remains, the ancient-woods layer has been dated back to about 8750 - 6200 years, and the vegetation was a subtropical evergreen and deciduous broad-leaved mixed forests on the island in the past. In the middle of the ancient-woods layer, two grains of wild rice were explored accidentally, which are Oryza rufipogon, along with the fruit and seeds of some water plants, such as Ceratophyllum demersum, C. oryzetorum, Euryale ferox, Trapa incisa var. quadricaudata , Scirpus yagara and so on. There might be marshy soil and a pond in ancient forest vegetation from where the grains of wild rice and hydrophytic fruit were found. It is of tremendous importance to study the origin of wild rice in China.

  16. Wood fuels consumption in households in Montenegro

    Directory of Open Access Journals (Sweden)

    Glavonjić Branko D.

    2013-01-01

    Full Text Available The paper presents the results of researching wood fuels consumption in households in Montenegro in the heating season 2011/2012. The research was conducted in the period October-November 2012 on the sample of 5% of the total number of households which stated to use solid fuels for heating purposes in the 2011 census. Results of the conducted researches on the presence and amounts of fuels consumed in households in Montenegro showed that total firewood consumption in the heating season 2011/2012 (both urban and rural households was 703,571 m3. Wood consumption is the lowest in the households in the municipalities in the coastal zone, it is somewhat higher in central zone and the highest in the zone on the north of Montenegro. Average wood consumption in households in the coastal zone municipalities is 3.79 m3, in the central zone it is 5.02 m3 and on the north of Montenegro it is 6.74 m3/household. Observed on the level of Montenegro, average firewood consumption per household was 5.49 m3 and as such it best represents relatively low consumption level in the coastal zone and high consumption level on the north of Montenegro. Compared to the neighboring countries, average firewood consumption per household in Montenegro in the amount of 5.49 m3 is significantly lower than the average consumption in Serbia which is 7.3 m3/household as well as in Slovenia in the amount of 6.5 m3.

  17. Energy wood procurement in connection with conventional wood procurement; Energiapuun hankinnan organisointi muun puunhankinnan yhteydessae - PUUT02

    Energy Technology Data Exchange (ETDEWEB)

    Maekinen, P. [Finnish Forest Research Institute, Vantaa (Finland)

    2001-07-01

    The research consisted of two sub-projects. The present role of forestry associations in procurement of energy wood was investigated in the first sub- project. The possibilities and willingness of them to increase the energy wood procurement were also studied. The role of forest machine and forestry service entrepreneurs in procurement of energy wood was investigated in the second sub-project. The effects of energy wood procurement on the operation of the forest machine companies in general were also studied in this sub-project. The sub-project three studied the requirements of the customer companies for the energy wood suppliers. All the material of the sub-projects was collected by personal inquiries. According to the executive directors of the forestry associations the role of the forestry associations in energy wood procurement varied between a by-stander and active participant. Active forestry associations announced the companies for stands available for cutting. They told also that they directed the harvesting to correct sites and deliver stems at the roadside. The role of the forestry association was emphasised especially when the associations on the basis of a letter of attorney carried out the timber trade. It was estimated that in the near future the operation of forest machine entrepreneurs in harvesting of energy wood would increase significantly. From the employment and turnover point of view the role of harvesting of energy wood was not seen as a significant matter. On the other hand, that harvesting of energy wood impede the harvesting of commercial timber was seen as a more significant matter. In the future the end-users of energy wood would like to have more competition in the energy wood markets. However, the energy wood suppliers were desired to be relative large so that the reliability of deliveries could be ensured. Simultaneously as the end-users wanted to decrease the price of forest chips, the machine entrepreneurs estimated the price to

  18. High-strength fiber-reinforced plastic reinforcement of wood and wood composite

    Energy Technology Data Exchange (ETDEWEB)

    Tingley, D.A.; Eng, P. [Oregon State Univ., Corvallis, OR (United States)

    1996-12-31

    Research and development underway since 1982 has led to the development of a method of reinforcing wood and wood composite structural products (WWC) using high-strength fiber-reinforced plastic. This method allows the use of less wood fiber and lower grade wood fiber for a given load capacity. The first WWC in which reinforcement has been marketed is glulam beams. Marketed under the trade name FiRP{trademark} Reinforced glulam, the product has gained code approval and is now being used in the construction of buildings and bridges in the United States, Japan and other countries. The high-strength fiber-reinforced plastic (FiRP{trademark} Reinforced panel (RP)) has specific characteristics that are required to provide for proper use in WWC`s. This paper discusses these characteristics and the testing requirements to develop code approved allowable design values for carbon, aramid and fiberglass RP`s for such uses. Specific issues such as in-service characteristics, i.e. long term creep tests and tension-tension fatigue tests, are discussed.

  19. Wood plastic composites from modified wood. Part 3. Durability of WPCs with bioderived matrix

    NARCIS (Netherlands)

    Westin, M.; Larsson-Brelid, P.; Segerholm, B.K.; Oever, van den M.J.A.

    2008-01-01

    The decay resistance of fully bio-derived wood plastic composites, WPCs, was tested in both laboratory and field tests. The laboratory tests were performed according to modified versions of AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils) and the field tests according to EN 2

  20. A model of supplying poplar wood for Iranian paper & wood factories

    Institute of Scientific and Technical Information of China (English)

    Majid Azizi

    2008-01-01

    The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran.Due to the destruction of the forests and lack of proper plantation,replacement of the forest wood by the fast growing wood is vital to satisfy all requirements of these factories.A hierarchy was used to prioritize benefits,opportunities,costs and risks (BOCR) using the Analytic Hierarchy Process (AHP) ratings approach.To evaluate the "control criteria" of the system,a control hierarchy was also created and prioritized by applying the Analytic Network Process (ANP).A total of four major control criteria in the system are prioritized where each one controls a network structure evaluated by using ANP.The final synthesis results of the system showed that internal poplar tree farming supplied by the forest product factories was the best choice among three potential alternatives (factory procurement,external procurement and mix procurement).