NEAR INFRARED SPECTROSCOPY FOR ESTIMATING SUGARCANE BAGASSE CONTENT IN MEDIUM DENSITY FIBERBOARD

Medium density fiberboard (MDF) is an engineered wood product formed by breaking down selected lignin-cellulosic material residuals into fibers, combining it with wax and a resin binder, and then forming panels by applying high temperature and pressure. Because the raw material in the industrial process is ever-changing, the panel industry requires methods for monitoring the composition of their products. The aim of this study was to estimate the ratio of sugarcane (SC) bagasse to Eucalyptus wood in MDF panels using near infrared (NIR) spectroscopy. Principal component analysis (PCA) and partial least square (PLS) regressions were performed. MDF panels having different bagasse contents were easily distinguished from each other by the PCA of their NIR spectra with clearly different patterns of response. The PLS-R models for SC content of these MDF samples presented a strong coefficient of determination (0.96) between the NIR-predicted and Lab-determined values and a low standard error of prediction (similar to 1.5%) in the cross-validations. A key role of resins (adhesives), cellulose, and lignin for such PLS-R calibrations was shown. PLS-DA model correctly classified ninety-four percent of MDF samples by cross-validations and ninety-eight percent of the panels by independent test set. These NIR-based models can be useful to quickly estimate sugarcane bagasse vs. Eucalyptus wood content ratio in unknown MDF samples and to verify the quality of these engineered wood products in an online process.

Avaliação tecnológica de painéis MDF de madeira de Eucalyptus grandis confeccionados em laboratório e em linha de produção industrial

MDF panels of Eucalyptus grandis wood fibers were made in either experimentally in a laboratory or on an industrial production line. In order to analyze the influence of the production condition, the anatomical, physical and mechanical properties of the panels were determined. The wood refining induced the transversal rupture of the transversal fiber wall. The MDF panels obtained from the industrial production line presented less swelling in thickness and absorption values and improved mechanical properties in the requirements of bending strength, module of elasticity and surface resistance. For laboratory MDF panels, it was possible to verify a statistically significant correlation between bending strength and module of elasticity, medium density and internal bond and swelling in thickness and absorption. This tendency was also true for the MDF panels obtained in real conditions of production, however without statistical significance. By comparing the quality properties of MDF panels produced in the laboratory with those obtained in real conditions of production, it was sought to standardize the established variables for obtaining panels on a small scale, as well to make possible the safe transfer and divulgation of information obtained in the laboratory.

An improved continuous medium technique for structural frame analysis

This paper presents an improved constitutive equation of frame in the context of continuous medium technique. This improved constitutive equation, which is a consistent formulation of column global bending, is applicable to a complete class of frameworks including the ideal shear frame panel, for which the beams are assumed to be rigid, and the associated column system, for which the rigidity of beams is negligible. Global buckling and second-order effects of the frame structure are discussed. The main results can be extended to other types of lateral stiffening elements as built-up columns. A worked example is presented in order to compare the main results with those obtained by the classic matrix method. Copyright (C) 2007 John Wiley & Sons, Ltd.

Biodeterioration of painted mortar surfaces in tropical urban and coastal situations: Comparison of four paint formulations

Four different architectural acrylic paint formulations were tested by exposure to weathering for 7 years in the urban site of Sao Paulo and the coastal site of Ubatuba, South-East Brazil. Surface discolorations and detachment of coatings were assessed and the components of the biofilms were identified by standard microbiological methods. The painted surfaces of the mortar panels were much more discolored in Ubatuba, where major components of the biofilms were the cyanobacteria Gloeocapsa and Scytonema. In two of the four paint films, a pink coloration on the surface at this coastal site, caused mainly by red-pigmented Gloeocapsa, produced high discoloration ratings, but low degradation (as measured by detachment). Biofilms in Sao Paulo contained the same range of phototrophs, but in lesser quantity. However, fungal numbers, as determined by plating, were higher. Detachment ratings in this urban site were only slightly lower than in Ubatuba. The matt paint performed worst of the four, with silk and semi-gloss finishes giving lowest biodeterioration ratings. The matt elastomeric paint performed well at both sites, apart from becoming almost 100% covered by the pink biofilm in Ubatuba. Unpainted mortar panels became intensely discolored with a black biofilm, showing that all the paints had achieved one of their objectives, that of surface protection of the substrate. The value of PVC (pigment volume content) as an indicator of coatings biosusceptibility, is questioned. (C) 2011 Elsevier Ltd. All rights reserved.

Modeling technique for honeycomb FRP deck bridges via finite elements

Honeycomb structures have been used in different engineering fields. In civil engineering, honeycomb fiber-reinforced polymer (FRP) structures have been used as bridge decks to rehabilitate highway bridges in the United States. In this work, a simplified finite-element modeling technique for honeycomb FRP bridge decks is presented. The motivation is the combination of the complex geometry of honeycomb FRP decks and computational limits, which may prevent modeling of these decks in detail. The results from static and modal analyses indicate that the proposed modeling technique provides a viable tool for modeling the complex geometry of honeycomb FRP bridge decks. The modeling of other bridge components (e.g., steel girders, steel guardrails, deck-to-girder connections, and pier supports) is also presented in this work.

Characterization of tree-rings of Pinus caribaea var. hondurensis Barr. et Golf. trees by X ray densitometry

This work aimed to determining the anatomical structure of wood, through methodology of histology and X-ray densitometry, of resin-tapped and not resin-tapped Pinus caribaea var. hondurensis trees samples, of three diameter classes. Pine trees, in forest plantation established in 1969, in the Ecological Experimental Station of Itirapina, from the Forestry Institute of Sao Paulo State, were measured and stratified into three classes of trunk diameter. The pine trees were resin-tapped since 2004, with the opening of two simultaneous and opposing panels. Sixty samples of pine wood trees were extracted from the tree trunk through a non-destructive method and in the laboratory. Tree rings were determined in the laboratory and wood apparent density by X-ray densitometry. The test results showed that: (i) false tree rings occur in the early wood and late wood of the tree rings due to climate change; (ii) the X-ray densitometry allowed the demarcation of the tree rings limits; (iii) the wood apparent density average was significantly different between the trees in high class diameter and in the medium-low class; (iv) the wood characteristics from the resin-tapped and non resin-tapped faces did not show significant differences.

WHO comparative evaluation of serologic assays for Chagas disease

Evaluation of commercially available test kits for Chagas disease for use in blood bank screening is difficult due to a lack of large and well-characterized specimen panels. This study presents a collaborative effort of Latin American blood centers and the World Health Organization (WHO) to establish such a panel. A total of 437 specimens, from 10 countries were collected and sent to the WHO Collaborating Center in Sao Paulo and used to evaluate 19 screening assays during 2001 through 2005. Specimens were assigned a positive or negative status based on concordant results in at least three of the four confirmatory assays (indirect immunofluorescence, Western blot, radioimmunoprecipitation assay, and recombinant immunoblot). Of the 437 specimens, 168 (39%) were characterized as positive, 262 (61%) were characterized as negative, and 7 (2%) were judged inconclusive and excluded from the analysis. Sensitivity and specificity varied considerably: 88 to 100 and 60 to 100 percent, respectively. Overall, enzyme immunoassays (EIAs) performed better than the other screening assays. Four EIAs had both parameters higher than 99 percent. Of the four confirmatory assays, only the RIPA gave a 100 percent agreement with the final serologic status of the specimens. The sensitivities and specificities of at least four of the commercially available EIAs for Chagas disease are probably high enough to justify their use for single-assay screening of blood donations. Our data suggest that the majority of commercially available indirect hemagglutination assays should not be used for blood donor screening and that the RIPA could be considered a gold standard for evaluating the performance of other assays.

Facade articulation, Neville Bonner Building, Brisbane

Detail of precast concrete sunshading panels to freeway (West) elevation.

Facade articulation, Neville Bonner Building, Brisbane

Detail of precast concrete sunshading panels to freeway (West) elevation.

Sedimentologic, petrographic, and sulfur isotope constraints on fine-grained pyrite formation at Mount Isa Mine and environs, Northwest Queensland, Australia

Fine-grained pyrite is the earliest generation of pyrite and the most abundant sulfide within the Urquhart Shale at Mount Isa, northwest Queensland. The pyrite is intimately interbanded with ore-grade Pb-Zn miner alization at the Mount Isa mine but is also abundant north and south of the mine at several stratigraphic horizons within the Urquhart Shale. Detailed sedimentologic, petrographic, and sulfur isotope studies of the Urquhart Shale, mostly north of the mine, reveal that the fine-grained pyrite (delta(34)S = -3.3 to +26.3 parts per thousand) formed by thermochemical sulfate reduction during diagenesis. The sulfate source was local sulfate evaporites, pseudo morphs of which are present throughout the Urquhart Shale (i.e., gypsum, anhydrite, and barite). Deep-burial diagenetic replacement of these evaporites resulted in sulfate-bearing ground waters which migrated parallel to bedding. Fine-grained pyrite formed where these fluids infiltrated and then interacted with carbon-rich laminated siltstones. Comparison of the sulfur isotope systematics of fine-grained pyrite and spatially associated base metal sulfides from the Mount Isa Pb-Zn and Cu orebodies indicates a common sulfur source of ultimately marine origin for all sulfide types. Different sulfur isotope ratio distributions for the various sulfides are the result of contrasting formation mechanisms and/or depositional conditions rather than differing sulfur sources. The sulfur isotope systematics of the base metal and associated iron sulfide generations are consistent with mineralization by reduced hydrothermal fluids, perhaps generated by bulk reduction of evaporite-sourced sulfate-bearing waters generated deeper in the Mount Isa Group, the sedimentary sequence which contains the Urquhart Shale. The available sulfur isotope data from the Mount Isa orebodies are consistent with either a chemically and thermally zoned, evolving Cu-Pb-Zn system, or discrete Cu and Pb-Zn mineralizing events linked by a common sulfur source.

Strain-dependent fluid flow defined through rock mass classification schemes

Strain-dependent hydraulic conductivities are uniquely defined by an environmental factor, representing applied normal and shear strains, combined with intrinsic material parameters representing mass and component deformation moduli, initial conductivities, and mass structure. The components representing mass moduli and structure are defined in terms of RQD (rock quality designation) and RMR (rock mass rating) to represent the response of a whole spectrum of rock masses, varying from highly fractured (crushed) rock to intact rock. These two empirical parameters determine the hydraulic response of a fractured medium to the induced-deformations The constitutive relations are verified against available published data and applied to study one-dimensional, strain-dependent fluid flow. Analytical results indicate that both normal and shear strains exert a significant influence on the processes of fluid flow and that the magnitude of this influence is regulated by the values of RQD and RMR.

Usefulness of liver biopsy in chronic hepatitis C

Major requirements for performance of liver biopsy (LB) are the benefits for the patient and the impossibility of having the same information by less invasive procedures. In the last two decades physicians have faced the difficult task of convincing a patient positive for hepatitis C, with minimal clinical or laboratory alterations to be submitted to LB in order to evaluate the status of the disease for therapeutic management. The characteristics of the needle used for percutaneous LB interferes with the accuracy of diagnosis. In chronic hepatitis C (CHC), validity is achieved with liver fragments about 25mm in length containing more than 10 portal tracts. Morbidity due to LB is mainly related to bleeding but death is very rare. Severe complications are also uncommon, increasing with number of passes and decreasing with experience of operator and ultrasound guidance. Although CHC is a diffuse disease, the various areas of the liver may not be equally affected and sampling errors are possible. Another potential limitation of LB is the discordance between pathologists in its interpretation. To replace LB, many panels of surrogate markers have been described, aiming to identify extent of fibrosis and inflammation. All of them have used LB as their ""gold standard"". Liver biopsy continues to be the most reliable method to evaluate the possibility of therapy for CHC. Universal treatment of all patients with diagnosis of CHC would be ideal. But, there are mainly three drawbacks. Overall efficacy is as low as 50%, side effects are common and may be severe and treatment is prolonged and expensive. The acceptability of the biopsy by the patient is highly dependent on the physician`s conviction of its usefulness.

A high-resolution genetic map of the familial Mediterranean fever candidate region allows identification of haplotype-sharing among ethnic groups

Familial Mediterranean fever (FMF) is a recessive disorder of inflammation caused by mutations in a gene (designated MEFV) on chromosome 16p13.3, We have recently constructed a 1-Mb cosmid contig that includes the FMF critical region. Here we show genotype data for 12 markers from our physical map, including 5 newly identified microsatellites, in FMF families. Intrafamilial recombinations placed MEFV in the similar to 285 kb between D16S468/D16S3070 and D16S3376. We observed significant linkage disequilibrium in the North African Jewish population, and historical recombinants in the founder haplotype placed MEFV between D16S3082 and D16S3373 (similar to 200 kb). In smaller panels of Iraqi Jewish, Arab, and Armenian families, there were significant allelic associations only for D16S3370 and D16S2617 among the Armenians. A sizable minority of Iraqi Jewish and Armenian carrier chromosomes appeared to be derived from the North African Jewish ancestral haplotype. We observed a unique FMF haplotype common to Iraqi Jews, Arabs, and Armenians and two other haplotypes restricted to either the Iraqi Jewish or the Armenian population. These data support the view that a few major mutations account for a large percentage of the cases of FMF and suggest that same of these mutations arose before the affected Middle Eastern populations diverged from one another. (C) 1997 Academic Press.

Critical review of acid in situ leach uranium mining: 1. USA and Australia

The technique of in situ leach (ISL) uranium mining is well established in the USA, as well as being used extensively in Eastern Europe and the former Soviet Union. The method is being proposed and tested on uranium deposits in Australia, with sulfuric acid chemistry and no restoration of groundwater following mining. Test sites in the USA were required to restore groundwater to ascertain the extent of impacts and compare costs to alkaline ISL mines. The problems encountered include expensive and difficult restoration, gypsum precipitation, higher salinity and some heavy metals and radionuclides after restoration. One of the most critical issues is whether natural attenuation is capable of restoring groundwater quality and geochemical conditions in an acid leached aquifer zone. The history of acid ISL sites in the USA and Australia are presented in this study, with a particular focus on the demonstration of restoration of groundwater impacts.

Experimental infections of pigs with Japanese encephalitis virus and closely related Australian flaviviruses

The flavivirus Japanese encephalitis (JE) virus has recently emerged in the Australasian region. To investigate the involvement of infections with related enzootic flaviviruses, namely Murray Valley encephalitis (MVE) virus and Kunjin (KUN) virus, on immunity of pigs to JE virus and to provide a basis for interpretation of serologic data, experimental infections were conducted with combinations of these viruses. Antibody responses to primary and secondary infections were evaluated using panels of monoclonal antibody-based blocking enzyme-link-ed immuno-sorbent assays and microtiter scrum neutralization tests (mSNTs). Identification of the primary infecting virus was possible only using the mSNTs. Following challenge, unequivocal diagnosis was impossible due to variation in immune responses between animals and broadened and/or anamnestic responses. Viremia for JE virus was readily detected in pigs following primary infection, but was not detected following prior exposure to MVE or KUN viruses. Boosted levels of existing cross-neutralizing antibodies to JE virus suggested a role for this response in suppressing JE viremia.